Controlling Floriday Betony

Now is the time to control Florida betony.  This weed is found throughout the southeast and has the paired leaves and square stem characteristic of the mint family.  Florida betony is also known as wild artichoke or rattlesnake weed.  Both of these names refer to the distinguishing structure of Florida betony – the swollen white tubers that are produced underground.  These tubers resemble the segments of a rattlesnake’s tail or a white grub.  These structures are responsible for the persistent nature of Florida betony.  The tubers are also edible.

Florida betony is a cool season perennial weed.  It goes dormant during the heat of summer but grows enthustiastically in the cooler temperatures of spring and fall.  Control of Florida betony depends on the location – treatment in lawns is easier than landscape beds.  

Controlling Florida betony in lawns requires a multipronged approach.  In lawns, the first step to weed control is to optimize turf growth.  A dense stand of regularly mowed grass will compete better against Florida betony and other weeds.  Follow the correct cultural practices for your lawn to make it as thick and healthy as possible.  This includes mowing at the correct height and frequency, as well as  fertilizing at the right time and rate for your grass type.   Cultural requirements vary depending on the type of grass you have in your lawn.  For more information, request a lawn maintenance calendar for your turf type from your local Cooperative Extension Office.  

There are selective herbicides that can be used for control in lawns but the herbicide option will depend on the type of grass you have.  Herbicides that contain 2,4-D as the active ingredient work well on zoysia and bermuda lawns.  Centipede and St. Augustine are sensitive to 2,4-D.  For this reason, atrazine is frequently used to control Florida betony in these turfs.  That said, combination products that contain 2,4-D, MCPP and dicamba (Weed-B-Gone, Spectracide 33 Plus) can be used on St. Augustine and centipede lawns as long as the lower label rates indicated for the turf type are used.  When using any product, it is important that your sprayer be properly calibrated to apply herbicide at an accurate rate.  As with any chemical, make sure you read and follow all label directions.  Stay out of the border of shrub beds or the drip line of individual trees or shrubs in the landscape when using these products.

Regardless of the herbicide you use, you will need to make more than one application to achieve control.  It often takes two years to completely control Florida betony.  The best time to spray for control is in the fall as the weed is starting to grow for the season (October-November) and again in the spring (February-March). 

Controlling Florida betony in perennial beds is more of a challenge.  Pulling is not very effective since it leaves tubers behind in the soil.  If you are going to remove Florida betony by hand, dig carefully to remove the tubers.  This technique is effective in small areas.  Make sure that tuber-infested soil is disposed of carefully so the Florida betony doesn’t spread to a new area.  Do not compost the tubers.  Applying a thick mulch, 3-4 inches deep, can help slow the spread of Florida betony but will not control it completely. 

Glyphosate (RoundUp and other brands) can be used to control larger infestations in flowerbeds.  Glyphosate is a non-selective herbicide so it will damage or kill any plant it comes in contact with.  However, careful targeted spraying can provide control.  Spray only when there is little to no wind and air temperatures are less than 85 degrees.  Some spray nozzles come with a cone that be used to prevent drift.  Certain product formulations marketed to homeowners now come with a “foam” setting that helps reduce drift and allow you to track application better.  Glyphosate application is particularly effective when the Florida betony is in flower – typically in mid to late spring. 

The key to effective Florida betony control is good management, appropriate herbicide selection, accurate timing of application and persistence.

Brand names are included as examples only and are not intended as an endorsement.  Active ingredients may be marketed under many different formulation and brand names.

Trees and Hurricanes

Hurricane Irene was not kind to the trees in Onslow County.  During my post-storm inspection of the county I noticed a lot of trees that were down or damaged to the extent that they needed to be removed.  However, it was interesting to note that the majority of the damage was limited to a very small number of tree species.  Bradford pears and pecan trees definitely bore the brunt of the damage but there were a smattering of water oaks down as well. 

So what do we do now?  Many people are afraid of any tree in a hurricane but it is obvious that some tree species withstand these high wind events much better than others.  The University of Florida (UF) has done extensive research on tree survival in hurricanes.  This study looked at many factors that related to tree survival in hurricanes but today we are going to look at just one factor: species selection.  Some tree species are simply more resistant to wind than others.  It would be wise to take this fact into consideration when choosing trees for your property. 

Good trees for our area that show the highest level wind resistance based on this study include: American holly, yaupon holly, crape myrtle, southern magnolia, live oak, bald cypress, pond cypress, and sabal palm.  Those rated medium-high for wind resistance include: Japanese maple, river birch, ironwood, sweet bay magnolia, shumard oak and hickories.  Consider using these species to reduce future storm damage potential on your property.

Equally important to note is which trees fared most poorly in the UF study.  Common local landscape trees that showed the lowest wind resistance include: pecan, tulip poplar, Bradford pear, southern red, laurel and water oaks, Chinese elm, and Leyland cypress.  These species should be avoided in landscape plantings.  Pecans should be situated well away from structures and power lines.  Likewise, red and silver maples, sycamore, white and willow oaks, weeping willow, and American elm scored medium-low wind resistance so avoid these as well or use them only with caution. 

We will discuss how to assess a storm-damaged tree and other factors relating to hurricane-survival in future posts.  Meanwhile for more information about hurricanes and trees, check out the University of Florida’s site Trees and Hurricanes here http://hort.ifas.ufl.edu/treesandhurricanes/. 

Slime Flux or Wet Wood

Several weeks ago, I had a very interesting home visit.  A woman told me that the sap was bubbling out of the base of her tree.  When I arrived, the sap was indeed bubbling out of the base of a mature oak tree.  It was bubbling along so quickly it made me think of a pot simmering on the stove.  There was a strong wine-grape smell in the air as well.  The sap was attracting a lot of green June beetles and an assortment of wasps and bees.  This is what I saw:

When I pried some of the outer bark off, the inner bark was soft and spongy:

After a little research, I found out that this a bacterial disease called "slime flux" or "wet wood".  Slime flux is a bacterial disease common in large, mature landscape oaks, tulip poplars and elms.  Bacteria carry out fermentation under the bark of the tree and produce carbon dioxide gas in the process.  The gas forces sap out of the bark under pressure - hence the bubbling. 

Slime flux isn't a serious problem if the tree is otherwise healthy.  These is no cure or prevention for slime flux other than maintaining trees in good health and minimizing wounds or injuries.If there is lose or dead bark in the affected area, remove the loose bark and allow the area to air dry.  Do not apply any sort of wound dressing.


You can learn more about slime flux here:
http://www.ces.ncsu.edu/depts/pp/notes/oldnotes/od8.html

Bradford Pears Blooming Out of Season

In my last email, I mentioned that a lot of bradford pears damaged by Hurricane Irene are reblooming now.  Blooming out of season is a normal response of plants that have been stressed.  This storm left behind an interesting phenomena - many of the affected trees are blooming only on the windward side.  This is same side that they lost most of the their leaves on during the hurricane.  The loss of leaves triggers a hormone response that promotes flowering.  The tree shown above is a perfect example - this tree is in front of the public library in Richlands.  

As long as these trees haven't lost large limbs, they will probably recover well over the longterm.  You may see some decrease in bloom next spring if your tree is blooming this fall.  I have also seen some cherry trees and azalea shrubs reblooming.
 

Fairy Ring

Rings of mushrooms may crop up after rain in the fall.  These rings are referred to as “fairy rings”.  The mushrooms are the fruiting bodies of a larger fungus that is growing in the ground.  Generally fairy rings only pose an aesthetic issue in home lawns.  Frequent moving will remove the mushrooms or you can knock them over with your foot as you see them coming up.  Over time, the fungus in the soil may make the soil resistant to water infiltration.  If grass starts to brown around the ring, frequent regular aeration (with a plug aerator or the tines of a pitch fork) will help promote water infiltration, soil rewetting and grass survival. 

Dividing Perennials

Dividing perennials is an enjoyable garden task that promotes plant growth while allowing you to create more plants in an easy, low-maintenance way.  Vigorously growing perennials like chrysanthemums and asters may need to be divided every season or two, while slower growing plants may never need to be divided except to propagate them.

Many perennial plants benefit from regular division but don’t divide on a time schedule, let the plant’s growth habit dictate whether you need to divide it.  Perennials need to be divided when: flowering is reduced or flowers get smaller, the center growth dies out but there is growth around the edges, bottom foliage is sparse, the plant loses vigor, the plant flops over or requires staking or it has simply gotten too large for its space in the garden.  Of course, even if your plant is growing and blooming well, you may choose to divide it to create more plants for your garden or to share with friends.    

Perennials should not be divided while they are in flower; flowering demands a lot of energy from the plant and you do not want to stress a plant by dividing it at the same time.  The general rule of thumb is to divide spring-flowering plants in the fall and fall-flowering plants in the spring.  Fall division should take place early enough that the plant has at least 4 to 6 weeks to establish roots before the ground freezes.  Spring divisions should be carried out early enough that the plant establishes new roots before hot weather sets in.

Prepare ahead of time.  Water your plants thoroughly a day or two before you plan to divide them and prepare the area that you plan to put your new divisions in.  You want to minimize the amount of time that the plants’ roots are out and exposed to the air.  If appropriate, prune the stems and foliage down to about 6 inches from the crown to ease division and cut down on moisture loss. 

Use a sharp pointed shovel or a spading fork to dig down and lift the plant or section of plant.  You will want to dig down all around the plant about 4 to 6 inches away from the base.  Slide your tool underneath the root mass and lift the clump out.  Shake loose soil off the root ball and remove any dead leaves or stems.

Division of the clump will depend on the growth habit of the plant you are dividing.  For any plant, remember that you need to maintain a portion of the growing point (crown) and a portion of the root system intact. 

Some plants can easily by divided by teasing the root system apart and separating the crowns by hand.  If the clump is more substantial, you may need to use two digging forks placed back to back to pull the crowns apart.  In some cases, you may need to divide the clump by cutting with a sharp heavy knife or handsaw.  Work your knife between the crowns and cut down through the clump and root ball making sure that each crown has a healthy portion of root attached.  Likewise, a sharp pointed shovel can be worked between the crowns and used to cut down through the root clump.  Whatever technique or tool you use, make sure each division contains at least 3 to 5 shoots.

Never allow your divisions to dry out.  Keep a bucket of water close by to keep them moistened until planting.  Prune off any broken or damaged roots prior to planting.  Plant your new divisions immediately in the prepared garden bed or in containers with a clean, coarse potting mix.  Plant divisions at the same depth that they were growing originally.  Firm the soil around the roots and water well after planting.  New divisions should be watched carefully and protected from drying out until the root system is well established. 

Not all plants benefit from division.  Butterflyweed, euphorbias, oriental poppies, Japanese anemones, and false indigo are all examples of plants that should not be divided.  Likewise, many woody plants don’t divide well.  Instead, look for a branch that has naturally layered near the base of the plant.  This can be dug up and replanted instead.

Caterpillars in the Garden or "It Pays to be Pretty"

Sometimes we get our blinders on when we get in the garden.  It is easy to get into an “us versus them” mentality when it comes to insects.  Often when we find a caterpillar in the garden, we consider it a pest and usually try to kill it.  However, I ran into two caterpillars this month that I didn't kill (mostly!).  

The first caterpillar I found in the HELP Garden earlier in the month.  This tomato hornworm is a pest of tomatoes.  If left unchecked, a couple of tomato hornworms can defoliate an entire tomato plant.  What made this particular hornworm interesting were the white tufts covering his back.  These white cottony protrusions are actually the cocoons of tiny braconid wasps. 

Braconid wasps are parasitoids of tomato hornworms.  The female wasp lays her eggs just under the skin of an unlucky tomato hornworm.  When the eggs hatch, the larvae feed on the hornworm – literally from the inside.  As the large mature, they work their way to the skin of the hornworm and spin their tiny cocoons.  After only four days in their cocoons, the newly mature wasps will emerge and fly away.  The weakened hornworm will die. 

As gruesome as this story is for the tomato hornworm, the little wasps are actually very beneficial to the gardener.  The wasps are tiny, less than an 1/8 of an inch long, and pose no threat to humans but they help naturally control the population of tomato hornworms in the garden.

The affected hornworm stops eating soon after the eggs hatch, so a parasatized hornworm does no additional harm in the garden.  If you see a hornworm that is covered with wasp cocoons, leave it in place so the braconid wasps can hatch and help control hornworm in your garden.

The second caterpillar I found in my home vegetable garden.  On my morning walk through, I noticed that my fennel was starting to look a little sparse.  Upon closer inspection I found a little green, black and yellow caterpillar.

 And then I found another one, and another one, and another one!

All of them were chomping away.

The bright color pattern clued me in that this was probably the caterpillar of a butterfly.  A quick visit to my butterfly field guides revealed the culprit, these were the caterpillars of a Black Swallowtail butterfly.  Because I like butterflies (and because the caterpillars had only infested the fennel in one bed), I let the caterpillars survive.  I guess the moral of this story is that it pays to grow up into a big, beautiful butterfly rather than a small, nondescript moth. 

Only a couple of days after that, the caterpillars had defoliated both of the fennel plants in that bed and had started in on the parsley.  Since I don’t eat much parsley, I left them alone.  

The largest caterpillar had already formed a chrysalis.  (Most butterflies only take about four weeks to reach maturity from an egg under ideal conditions.) 

 This morning, I inspected my now leafless (and soon to be lifeless) fennel plants but other than the chrysalis the caterpillars are gone.  Apparently the cowpeas, tomatoes and pepper plants left in that bed weren’t to their tastes.  When I went to check the other bed however, I found a big, fat caterpillar starting to chow down on my last remaining fennel plant.  Even I have my limits, I practiced a mechanical control technique – I picked the caterpillar off the fennel and carried him to the chicken yard.  The girls took care of the rest.

Did someone say caterpillar???

Hey, you have to have balance.

Happy gardening. 

Tomato Cracking

Tomatoes are susceptible to skin cracking, especially this time of year.  Cracking is a result of rapid fruit development usually combined with fluctuations in water availability.  If a tomato starts to ripen during dry weather and is then subjected to lots of moisture (heavy rain or excessive irrigation) and high temperatures, the fruit will swell quickly bursting the skin.  Tomatoes may split radially (as in the photo above) or in concentric circles around the the shoulders.  Either way, the cause of the cracking remains the same.

There are several steps you can take to reduce the likelihood of cracking in your garden:

• Provide regular, consistent irrigation (approximately one inch of water per week, may need to increase amount or frequency in sandy soil).  Monitor rainfall with a rain gauge and don’t irrigate if it isn’t necessary.  Containerized plants may need more frequent watering depending on the size of the container.

• Mulch the soil to conserve soil moisture. 

• Fertilize according to your soil sample report – plants that are subject to high nitrogen and low potassium levels are more susceptible to cracking. 

Some varieties of tomatoes are more susceptible to cracking than others when grown under the same conditions.  Supersonic and Jetstar are two varieties that show relatively low incidence of cracking in studies.  In my garden, Cherokee Purple cracks consistently (on right above) while Carolina Gold (on left above) cracks very little.  As for my cherry tomatoes, Supersweet 100 (below) is intermediate, while Jolly Elf (not shown) cracks very little. 

Certain varieties, particularly some heirloom varieties, will crack early in their development.  The cracks may become very deep but often callus over and do not rot if the weather isn't too wet.  This is Brandywine Red below.

Cracked tomatoes are not pretty but can be harvested and used right away.  They will not keep because decay can set in quickly.  If you have tomatoes on the vine and are anticipating a heavy rain, consider harvesting them before the rain event and letting them ripen at room temperature until you are ready to use them.    

Save Water - Take the 40 Gallon Challenge

Find out how you can save money and live more sustainably:
Take the 40 Gallon Challenge!

Conserving water is important everyday, not just during a drought. Even in years with adequate rainfall, water demand can exceed supply. By reducing your home and landscape water use you can reduce your water bill, live more sustainably, and protect our local environment. The 40 Gallon Challenge can help you do this by introducing simple, inexpensive practices you can put into place in your home and yard to reduce water use.

The 40 Gallon Challenge encourages people to save a minimum of 40 gallons a day by adopting new water-saving techniques. The challenge began in 2011 as a voluntary campaign to increase water conservation. The Challenge was launched by Cooperative Extension in several southeastern states, including North Carolina.

The online pledge card outlines water-saving practices and the daily water-savings to expect. You can use the pledge to review the water-saving practices that you or your family currently puts to use. By pledging new practices, you will see the total daily savings expected for your household.

The 40 Gallon Challenge also provides maps and charts to see pledge activities in your state and across the United States. Currently Onslow County only has four committed participants.  Sign up and help us make an impact on water conservation in our region!

To start saving water and take the challenge, go to the website, http://www.40gallonchallenge.org/state.cfm?state=NC,  and complete the checklist of water-saving practices. The checklist includes both indoor and outdoor water-saving tips.The website also shows the most popular practices being pledged, the pledged practices that are saving the most water daily, and counties and states that are pledging the most daily savings.


Learn more about indoor and outdoor water conservation from these great resources:

• Save Water NC: http://www.savewaternc.org/
• Water Use It Wisely: http://www.wateruseitwisely.com/
• NC Extension Water Conservation Publications: http://www.bae.ncsu.edu/programs/extension/publicat/wqwm/usewtr.html

Freezing Fruit

 

I love the idea of preserving fresh produce.  If I had all the time in the world, I would stay home to can, pickle, jam and preserve to my heart’s content.  The reality is that I'm lucky if I make it home from work in time to pick the tomatoes before they fall off the vines and walk the dogs before I go to bed.  A majority of my fresh, seasonal produce is eaten standing in the garden or leaning over the sink.  If I'm feeling really spunky, I'll make a salad or a quick sauté.  Therefore, my dreams of elaborate food preservation are mostly that - dreams.  However, there is a quick produce preservation technique for which even I can find time: individually freezing berries and fruit.            

Individually frozen fruit is easy to measure out and use throughout the season.  It will lose some of its texture when it thaws but the flavor will remain fresh and vibrant.  If you don’t like the softer texture of the previously frozen fruit, use it in cooked recipes, smoothies or sorbets.  This technique works well for blueberries as well as raspberries, strawberries, peaches and other soft fruits.  You can cut larger fruit into pieces before freezing.              

First, find your produce.  You can harvest your own fruit, visit a pick-your-own-farm or make arrangements to pick up a bulk order of produce at your local farmers’ market.  I made arrangements with a vendor at the farmers’ market to pick up ten pounds of blueberries one afternoon.  This way, I could get all my berries frozen and out of the way in one day.       

Pick out any leaves, stems, unripe or overly ripe fruit. There is very little waste if you process your fruit quickly.  If you are using larger fruit, cut it into smaller pieces. 

Spread the fruit in a single layer on cookie sheets. Place the sheets in the freezer until the fruit is frozen solid (usually just a couple of hours).

Transfer the frozen fruit into heavy-duty freezer bags, squeeze out as much air as possible, seal and return them immediately to the freezer.

The individually frozen fruit will be easy to scoop or pour out as needed.

Frozen blueberries can be used in the same ways that you would fresh berries. Pies, cobblers, muffins, pancakes, and oatmeal are among my favorite ways to enjoy them.  Frozen fruits of all sorts are very versatile.  Consider the following ideas for using frozen fruit:

·      Substitute for fresh fruit in pies, cobblers or crisps

·      Add to pancakes or muffins (don’t thaw them or the juices will bleed through the batter)

·      Use in smoothies, sorbets or ice cream

·      Frozen fruit (especially grapes) makes a neat replacement for ice cubes in beverages or a tasty, refreshing snack eaten straight from the freezer

This technique for individually frozen fruit is quick, easy and versatile.  Don’t miss out on your chance to preserve fresh produce for use through out the year.

Soil 101

This week, I want to share an excellent blog post from garden writer Barbara Ellis.  You can find her blog, Eastern Shore Gardener, at http://easternshoregardener.com/2011/07/19/soil-101/#more-261 .  Barbara is situated on the Eastern Shore of Maryland but her discussion of soil and soil building is very applicable to eastern North Carolina.  Her gardens are lovely and full of interesting plant selections.  Enjoy!

Soil isn’t the sexiest topic for a blog post, but it’s been on my mind quite a bit of late. Part of the reason is I just finished editing/rewriting an e-book on composting for a client, and the organic matter in compost is at the heart of great garden soil. I’ve also had conversations with several friends and gardeners about soil recently. (Yes, I am the nerd that sits under an umbrella at a pool party and talks compost and compost making with fellow gardeners.) So, it’s no surprise that I’ve been thinking about my own composting efforts and the state of my soil’s organic matter.



Above: A stockpile of chopped leaves for amending soil and mulching at Mt. Cuba Center in Greenville, Delaware.

Building Healthy Soil
Since healthy soil is the key to having a successful garden, understanding a bit about what’s going on down there is helpful. I could actually sum up a post about soil improvement in a single sentence: Add organic matter as often as possible. It’s that simple. You really can’t add too much organic matter. Plus, that statement applies to soil improvement everywhere, not just here on the Eastern Shore. In my garden, I mostly add it by amending soil when planting and by mulching with organic matter such as composted wood chips or chopped leaves. I also compost religiously, although I don’t have fast, hot compost piles that need turning regularly.

Organic matter is an essential part of any healthy soil, even though it only makes up about five percent of the total volume of good soil. (The term organic matter refers to plant and animal matter, both living and dead, so it includes things like living and dead plant roots, bacteria, fungi, insects, etc.) It plays multiple roles, but one essential function is that it helps hold water in the soil. Humus is the dark colored stable form of organic matter that remains after organic matter such as compost has been digested completely by soil microorganisms. It can hold 80 to 90 percent of its weight in water. (In laboratory tests, where water doesn’t drain away as it does in soil, humus can hold 180 percent of its weight.) Another essential function of organic matter is that it feeds beneficial microorganisms and animals in the soil—and in a compost heap. These microorganisms and animals are responsible for fueling the decay cycle that releases nutrients to plants.

Understanding Texture and Structure
Most gardeners have heard of soil texture, even if they haven’t heard that term specifically. Soil texture refers to the sand, silt, and clay portion of soil. Here on the Eastern Shore, clay soil is a common complaint, but there also are gardeners who find themselves dealing with sandy soil. According to the USDA Soil Conservation Service’s Soil Survey of Kent County, Maryland, silt loams are a common soil type. My own garden is mostly silt loam. (The Survey contains lots more information about particular soil types, including the fact that all of the soils on our property have a high water table along with moderately slow to slow permeability. That means if I want to grow plants that need well drained soil, especially in winter, I need to pick sites carefully!) In my garden, prior usage also is an important factor. There used to be a public landing on our property, so berms of mixed soil and rock plus areas with solidly compacted soil are constant challenges.

The bad news about soil texture is this: From a practical standpoint, you can’t change it. Adding a bag or three of sand to a clay soil just makes cement. It doesn’t improve conditions for plants. The good news is that you can change another characteristic of soil, and that is its structure. Plus, creating soil with good structure does improve conditions for plants. Gardeners who talk about friable soil are referring to soil that has good structure, and organic matter plays a very important role in creating it.



Above: To prepare beds here at Hackberry Point, I add plenty of organic matter, plus add topsoil as needed to level out sites where there isn’t sufficient soil.

Soil structure refers to the way the individual particles—the sand, silt, and clay—clump together. Organic matter, and the organisms that help decompose it, play major roles in helping soil particles form clumps, called aggregates. Aggregates in good soil break apart easily. (These aren’t the hard clods that develop when clay soil dries out!) The spaces in-between the particles and the clumps are important, too. Soil with good structure has large pores that allow water to drain away easily, to be replaced by oxygen and carbon dioxide (air), along with small pores that hold water in the soil where it is available for plant roots.

Here’s the fact that stunned me when I was first learning about soil: Fully half of the total volume of good soil can be composed of pore space. The percentage of pore space varies, obviously, but in ideal conditions only 45 percent of the volume is composed of minerals (sand, silt, and clay). Five percent is organic matter. The rest of soil is pore space. Half of that pore space (25 percent of the total volume) is composed of large pores that fill up with water during rainstorms, but drain quickly and then hold air in the soil, which roots need to grow and beneficial soil organisms need to survive. The other 25 percent of the pore space consists of small pores that hold water in the soil.

Understanding how soil clumps or aggregates form—and how they can be destroyed—is important for any gardener who wants to improve the performance of their plants. Once you know about the existence of pore space, it’s immediately clear why walking on the soil isn’t a good idea: It crushes aggregates and smashes the pores, and thus affects the balance of water and air available to plant roots. Aggregates form, and soil structure develops, as water in the soil freezes and thaws, as earthworms and other organisms dig around in the soil, and as plant roots tunnel through soil—and also as they die. As they digest organic matter, soil microorganisms also secrete substances that help aggregates form. Organic matter fuels the processes that yields great friable soil, and adding it improves sandy soil as well as clay. Here’s how:

Sandy soil. Droughty and low in nutrients, sandy soil has lots of large pores with very few small ones. (Pure sand has no structure at all.) Sandy soil also has a high metabolism, meaning that microorganisms burn through organic matter at a very high rate. One reason that organic matter gets consumed so quickly is that there’s plenty of air present for microorganisms. While clay particles, and to a lesser extent silt particles, are quite effective at holding nutrients in the soil, sand particles aren’t, which is why sandy soils are low in nutrients. Adding organic matter helps fix both of these problems. To keep pace with sandy soil’s high metabolism, add compost or other organic matter to the soil every time you dig a hole. Also keep sandy soil covered with organic mulch to protect it, replenish organic matter, and help keep it cool.

Clay and silty soil. Unlike sandy soil, clay soil has a multitude of tiny pores. The clay particles and tiny pores are quite effective at tightly holding on to nutrients and water. For this reason, clay can be very fertile. The problem with clay is that nutrients are held so tightly plants can’t take them up. Plus, when it rains, there aren’t enough large pores, so water doesn’t drain through them well, and plant roots can’t get the air they require to grow. Clay can be wet and cold in spring, too. And if clay soils dry out, they turn to concrete and can be very hard to re-wet. Silty soils fall between clay and sand, but organic matter functions the same way: It helps fuel microorganism activity and the formation of soil aggregates, which help form large soil pores and thus bring air down into the root zone.

Preserving Soil Structure
It’s important to remember that soil aggregates are fragile. They are always breaking down and ideally new ones are always forming. Stop adding organic matter, and the process slows down. It’s also really easy to destroy soil structure, regardless of how much organic matter you add. Walking—or driving—on soil as well as tilling frequently are common ways structure gets destroyed. Tilling is especially a problem in vegetable gardens, since it breaks apart aggregates. Break apart the aggregates too many times—especially without adding more organic matter—and the large pore spaces will be destroyed. So, always add more compost or other organic matter whenever you till. Spread a layer of compost or well-rotted manure over the site, then work it in. Better yet, avoid tilling whenever possible. And, the next time you think about walking on soil, cutting through a garden bed, or, worse yet, parking on it, remember that 50 percent of good soil is pore space. Crushing the pores causes compaction and damages the pathways that take air and water through the soil.

Designing beds that are narrow enough to reach in from either side to tend plants is one way to keep from walking on the soil. In my garden, I wanted large, deep beds that are far to wide to tend from either side. So, my beds feature a network of narrow paths that allow access to plants without trampling on the soil. I also have maintenance paths that run behind beds for access. While these steps don’t always keep me off the soil, they eliminate most of my infractions.



Above: A maintenance path runs along the back edge of this border, along the base of the wall to allow access to plants without trampling on soil.

Digging, tilling, or turning soil when it is too wet or too dry also destroys soil structure, again because it breaks up the essential aggregates. Before getting to work in the garden, always pick up a handful of soil and squeeze it into a lump. If the lump crumbles into dust when pressed with a finger, the soil is too dry. Water deeply and test again the next day. If a handful of soil squishes into a lump that can’t be easily broken apart with the press of a finger, the soil is too wet. Wait a day or two, then test again before digging. Finally, if a handful of soil can be squeezed, but breaks apart easily when pressed with a finger, the soil is suitable for digging.

Feed the Community
Finally, it’s important to remember that organic matter gets used up, and replenishing it is an important aspect of gardening. Healthy soil is a living community that is rich with microorganisms, fungi, and a host of insects and other soil-dwelling animals. Organic matter is the fuel that keeps the community going and as it’s this community that releases that feed your plants and help build soil aggregates. A portion of the organic matter microorganisms feed on is supplied naturally, as microorganisms die, for example. But to maintain a robust community, and therefore healthier plants, adding organic matter is essential.

In vegetable gardens replenishing organic matter is especially important, since nutrients from the soil are taken away when produce is harvested. Here, applications of compost, well-rotted manure, mulch, and even cover crops supply the soil. In flower gardens and around permanent plantings of trees and shrubs adding organic matter is a little harder. Keeping the soil covered with composted wood chip mulch, shredded bark, or chopped leaves on the soil is the first step. It’s also a good idea to spread compost or a commercial product like Leaf Gro under mulch and add it to soil whenever you dig or plant. (Avoid using peat moss, which is not a renewal resource and also acidifies the soil. Also avoid using dyed mulch. For one thing, the dye can hide pressure treated wood which contains chemicals you don’t want added to your soil.)

Okay, enough already! (Does this post help you imagine our conversation at that pool party?) I hope this post will help some of you think about your soil a little bit differently next time you step out into the garden. It’s really quite an amazing gardening partner.

Tomato Update

I've been fielding lots of tomato questions in the clinic lately. The top four questions and their answers
follow:

My tomato plants were doing great but then the entire plant suddenly wilted. What’s happened?

Southern bacterial wilt and to a lesser extent southern stem rot are the most common culprits. If you cut the bark off of the stem and see brown discoloration in the vascular tissue, southern bacterial wilt is the culprit. If white fungal growth is visible at the base of the plant, it is likely to be southern stem rot. There is no cure for either of these diseases because both are caused by organisms that live in the soil for years. Pull up and destroy any affected plants. Rotate your tomatoes to another spot in the garden or relocate your garden altogether. If this is not possible, consider growing tomatoes in containers starting with clean, bagged soil or potting mix.


My tomatoes seem to have stopped growing and are starting to look stunted. The young leaves are purplish-brown and appear to be dying. What’s going on?

This could be a viral disease called tomato spotted wilt virus (TSWV). The disease is transmitted to the tomato plants by tiny insects called thrips. The symptoms usually appear first at the top of the plant but eventually spread. There is no cure for this disease either. Remove infected plants from the garden. Eliminate weeds in and around the garden that may harbor thrips. We only have one flush of thrips annually here so you can go ahead and replant tomatoes in your fall garden without fear of the disease returning. There are several TSWV resistant varieties of tomatoes available including Amelia, Crista and Talledega.

Why are my tomatoes flowering but not setting fruit?

Tomato pollination and fruit set occurs best when night temperatures are between 60 and 70 F. When night temperatures consistently stay in the mid-seventies or higher, fruit set will diminish dramatically.

What causes rot on the blossom end of my tomatoes?

“Blossom end rot” is a disease that occurs when tomato plants cannot move enough calcium out of the soil. If blossom end rot is a problem in your garden, make sure you sample your soil and lime according to the sample recommendation. Blossom end rot can occur even with adequate soil calcium levels if the plant is not able to take up the calcium efficiently. This can occur during a drought if plants aren’t watered regularly.

I have also seen several tomato plants (and other crops) that have been damaged by herbicides. Tomatoes are very sensitive to certain chemicals including glyphosate. Take special care when using herbicides around the garden and remember that herbicides can drift if the wind is blowing or volatilize if temperatures are high. Herbicide injury frequently results in abnormal “strappy” growth, marginal burn on the leaves or discoloration of the veins of the leaf.

I am seeing a fair number of aphids on tomatoes. This is probably because of the stress the plants are under due to the drought. Aphids can be easily controlled with insecticidal soap, just make sure that you treat the underside of the leaf and the new growth where most of the aphids are found.

In the Garden Now

The July-August edition of In the Garden Now is available online at:
http://onslow.ces.ncsu.edu/content/In%20The%20Garden%20Now

Topics include: Surviving the Drought, Tomato Update, Ground Pearls and the Onslow County Farmers' Market.  You will also find ideas for using the blueberries and sweet corn that are in the garden now as well as upcoming community classes.

Brandywine Red, one of the most reliable heirlooms in my experience.

Tomato Tips: Things to think about before you buy and plant

Its that time of year and people are rushing out to buy tomatoes.  However, I encourage you to stop and think about what you and your tomatoes need to have a happy, healthy growing season.  This is one time when it doesn't pay to be impatient. 

Tomatoes are a warm weather crop and don't flourish until day time temperatures are well into the 60s and night time temperatures are above 50 F.  If you set your plants out the beginning of April, they will not grow vigorously until the soil and air temperatures warm up towards the end of the month.  Meanwhile, tomatoes are very sensitive to frost.  The last frost date in our area tends to occur around April 15 to 20 although it can occasionally happen as late as the first week in May.  If you buy tomatoes earlier, you will need to protect them from cold nights until the weather warms.  You are better off waiting until after the last frost date to buy and plant your tomato seedlings.  These plants will likely grow more quickly and vigorously than tomatoes planted in cold soils early in the season.

Varietal selection is important when choosing what tomato varieties you want to grow.  At the very least, you need to consider their growing habits (determinant versus indeterminant tomatoes) and disease resistance.

Many of us have heard the terms determinant and indeterminant but what do these terms mean?  Determinate tomatoes bear a single large harvest while indeterminate tomatoes bear fruit over a longer harvesting season. Determinate varieties are often (but not always) more compact while indeterminate varieties tend to grow longer vines and require more support.

So which type should you grow? Determinate varieties are a good choice for people who like to make sauce, can or dry tomatoes. If you use tomatoes mostly for snacking and eating fresh, indeterminate varieties will provide you with tomatoes throughout the season. If you are growing your tomatoes in a container, a determinate variety will tend to be more well-behaved and not require as much support and pruning to maintain as an indeterminate variety. When shopping, look for the abbreviation DET (determinate) or IND (indeterminate) on the label. Most cherry tomato and heirloom varieties are indeterminate.

If you choose to grow determinate tomatoes, you may want to select several different varieties to ensure early, mid and late season crops. Look at the seed package to determine the number of days from seeding until fruit set.  Choose varieties with different maturity dates if you want production throughout the season.  Remember that the seed sowing date and growing conditions will affect the actual fruiting date.

"Suckering", or removing the side shoots that develop between the main stem and a leaf, is a common practice but it is not desirable for determinant varieties because it will decrease yields. You can sucker your indeterminate varieties but it may not be necessary if you have a vigorous, well-caged plant.

Disease resistance is an important characteristic in tomatoes.  Some tomato varieties are naturally more resistant to certain diseases than others.  If you can determine which diseases are issues in your garden, you may be able to choose varieties that are less susceptible.  Two diseases of particular issue in Onslow County are Tomato Spotted Wilt Virus and Southern Bacterial Wilt. 

Tomato Spotted Wilt Virus (TSWV) results in tomato plants that stop growing and look stunted.  The young leaves may look purplish-brown and appear to be dying.  This is a viral disease that is transmitted by tiny insects called thrips.  The thrips transfer the virus from weeds around the garden to the tomato plants.  If you have experienced TSWV in the past, look for a tomato variety that lists TSWV on the package, indicating that the variety carries some natural resistance to this disease.  Also, eliminate the weeds in and around the garden area that harbor this disease.

Southern Bacterial Blight is a common soil-borne disease in our area.  This disease results in plants wilting (despite adequate soil moisture) as the bacteria blocks up the vascular system of the plant.  Initially plants may wilt only on hot afternoons and revive by the next morning.  As the disease progresses, the entire plant will wilt permanently and die.  The bacteria that causes this disease lives in the soil and can persist for years so your best treatment is to relocate your tomatoes (in another part of the garden or another location all together).  You may also consider growing your tomatoes in containers using clean potting mix.  There are very few tomato varieties that are naturally resistant to Southern Bacterial Blight and the few that are do not have high quality fruit.

These are just two of the diseases that can affect tomatoes.   You may see other acronyms on your tomato packet including TMV (Tobacco Mosaic Virus resistance) and N (Nematode resistance). 

So please be patient.  Wait another week or two before buying your tomato plants, choose your varieties carefully, plant them when the soil and nights are warm, and give them the best possible chance to grow and thrive.          

The Impatient Gardener

I am an impatient person.  I can’t wait for spring, warm weather and to start digging in the garden.  I check my seedbeds obsessively until I see the first little green leaves emerging.  Then I stand back and tap my toes until the plants present the first buds, flowers and, finally, fruit.  And then at the end of the season, I impatiently wait for the next growing season to start.  Now don’t get me wrong, I know the schedule and how plants work but I can’t help myself.  I want something growing, all of the time and I don’t want to have to fuss over it too much. 

I finally admitted that I am an impatient gardener several weeks ago when I found myself out in the garden carefully digging to uncover a seed potato.  I had planted the potatoes two weeks before and couldn’t stand it any longer.  I dug down “just to see what was going on”.  In reality the potatoes were only a couple days away from emerging but I couldn’t wait – I just wanted to make sure the little suckers were really doing something!

The potatoes were doing exactly what they were supposed to be doing and emerged right on schedule (yes, even the one I dug up) and I realized just how impatient I really am.  Sometimes being a little impatient is a good thing though.  It makes me look at what I am doing and ask, “Is this really necessary?” or “What can I do make this process more efficient?” 

  

In this blog, I want to focus on the things that make an impatient gardener tick: the principles and practices that give us the most bang for our gardening buck and limited time.  What do we really need to do for our garden to succeed and flourish?  What techniques let us maximize our production in a limited space?  What practices minimize the amount of busy work we need to do in the garden?  What little secrets will let us go out and pick produce out of our own gardens when everyone else is headed to the grocery store? 

I hope that you will join me in this process, even if you aren’t an impatient gardener.