Tomato Hornworms and Parasitic Wasps

Tomato hornworms (Manduca quinquemaculata) are a serious problem for tomato growers. These caterpillars have a large appetite and can quickly defoliate a tomato plant. If you find hornworms in your tomatoes, simply pick them off and drop them in soapy water. However, if you find a hornworm with white oblong obtrusions, leave it!

The white obtrusions are actually the cocoons of a parasitic wasp. A female wasp has laid her eggs under the skin of that hornworm. As the eggs hatch the larvae actually feed on the hornworm insides. The larvae eat their way out of the caterpillar and spin the cocoons you see. Eventually adult wasps will emerge from the cocoons and the weakened hornworm will die.

Photo credit: Texas A&M

The hope is that the emerging wasps will find other tomato hornworms to parasitize and you will have managed that pest. There are some generalist parasitic wasps that will provide that service for you. There is a braconid wasp, Cotesia congregates, that specifically looks for tomato hornworms. This small wasp has clear wings and as an adult they are nectar feeders. To persuade the wasps to stay in your garden you will need to have flowers. The small braconid wasps are attracted to small flowers like yarrow and small asters.

Instead of reaching for an insecticide for tomato hornworms encourage the ecosystem to assist you in managing that pest!

Happy Gardening!

Tomato Terminology for the Georgia Garden

Over the next weeks we will be exploring the world of tomatoes. They are the most popular plant in community gardens. But tomatoes can be problematic. Together we will share the good, the bad, and the delicious of tomato growing. Please share your experiences. To begin our tomato journey we are going to look at some tomato terminology.

Tomatoes in Hay BalesDeterminate vs. Indeterminate

When deciding on what type of tomato plants you want to grow, choose if you want determinate or indeterminate varieties.  Determinate plants bear all of their fruit at one time.  The plants tend to be more compact and easier to manage.  You will probably still need to support them with a tomato cage or staking.  Determinate varieties are popular with growers who want to preserve the fruit, make tomato sauces, or salsas as they get all the fruit at once.

Indeterminate varieties bear their fruit throughout the growing season.  The plants tend to sprawl and will definitely need support by staking or caging.  Growers who like to eat fresh tomatoes throughout the summer prefer indeterminate varieties.

Tomato Disease Resistance

Due to successful tomato breeding gardeners now can choose tomatoes that show resistance to the common diseases that plague all tomato growers.  A note of disclaimer here – remember that disease resistance does not mean disease proof.  You can easily determine the disease resistance of a particular variety by the initials after the name:

Big Boy VFN Tomatoes
Big Boy VFN Tomatoes

V – Resistance to the fungus that causes Verticillium wilt.

F, FF, or FFF – Resistance to the fungus that causes Fusarium wilt.  Sadly, some of the fungi developed immunities to the resistance qualities of the initial “F” tomatoes, so breeders developed cultivars that are resistant to the newer fungal races so now you may see “FF” and “FFF”.

N – Resistance to nematodes

T – Resistance to the Tobacco Mosaic Virus

TSWV– Resistance to the Tomato Spotted Wilted Virus

A – Resistance to the fungus that causes Alternaria Stem Canker

St – Resistance to the fungus that causes Grey Leaf Spot, Stemphylium solani.

Big Boy VFN shows resistance to Verticillium wilt, Fusarium wilt, and nematodes.    Tomato plant sellers in your area should stock the tomatoes with the resistance you need.  Look for the resistant cultivars in seed catalogs as well.

Don’t rely on planting disease resistance cultivars as your only line of defense against disease.  Good cultural practices like proper irrigation, mulching, soil building, fertilization and removal of diseased plants are examples of the integrated pest management (IPM) you should be using.

If you think your tomatoes have one of these diseases contact your local UGA Extension office for confirmation.  Georgia Home Grown Tomatoes is an excellent publication for tomato connoisseurs.

Happy Tomato Gardening!

 

This is My Heirloom Seed Story. What’s Yours?

My family hails from deep in the Appalachian Mountains. My mother’s ancestors came with Daniel Boone’s family through the Cumberland Gap and into what is now Breathitt County, Kentucky. My father’s family settled in Pike County, Kentucky, where he grew up at the back of church house holler. I am a McCoy from Hatfield and McCoy fame and like most people from Appalachia I have an heirloom bean seed story.

Beans in these mountains have been grown and handed down for centuries. Most Appalachian beans are cornstalk beans, meaning traditionally they were grown along with tall, open-pollinated corn. The tall corn stalks supported the long, bean vines. As time went on and hybrid corn stalks became shorter, people grew the beans on poles for support and they became “pole beans.”

As commercial beans became popular, large growers bred their beans for a tough outer shell or pod. The tougher shell meant that the beans could better stand mechanical harvest and handling. Appalachian beans are prized for their softer shell and full bean kernels. They have names like Lazy Wife Greasy Bean and Turkey Craw Bean. Eaten fresh or dried for winter dishes, they are family legacies. There are festivals honoring the Appalachian bean all across the mountains where seed swaps take center stage.

My bean seed was given to me by my Aunt Tillie. She received them from her mother who got them from her mother, and so on. My Jonah Beans are more of a bush bean than a cornstalk bean. In my north Georgia home, I can get three plantings of Jonah Beans each season. I generally grow enough for my family to enjoy and to put up a few canned jars. Of course I save seed year to year.

Jonah Beans in the May Garden

Beans are harvested, strings are removed (usually while sitting on the front porch) and prepared fresh. They are best cooked with a strip or two of bacon and a side of skillet cornbread. Happily, bush beans are a great addition to a community garden plot. They can also be used in school gardens with timely planting.

I am honored to be a keeper of this seed, of this mountain tradition. Planting, harvesting and preparing them is more than just growing beans. It is a way to connect with my heritage and to share that heritage with the next generation. If you are interested in Appalachian heirlooms Bill Best’s book Saving Seeds, Preserving Taste is a fantastic resource full of stories.

That is my heirloom seed story, what’s yours?

Soil Temperatures in Your Georgia Garden

Soil Temperatures in Your Georgia Garden

With the recent warm temperatures it is easy to be seduced into planting your summer crops now.   It is tempting to plant our vegetable transplants and seeds; we can’t wait for that first juicy tomato are a crunch pepper!  Be aware that soil temperatures are very important for success with your early summer plantings.

Soil Temperatures in Your Georgia Garden
Pepper Seedlings

Soil temperatures need to be 60-65 degrees F and rising at the 4 inch soil depth before you plant your summer crops.

If you install a transplant too early the roots won’t grow and the plant will just be sitting in the soil.  If we have a large amount of rain, which seems to be the norm this year, your new plant will just be sitting in wet soil.  This could mean early disease issues.

This morning the Ballground weather station, near my home, indicated a 4-inch soil temperature of 54.6 degrees F. In Griffin the 4-inch soil temperature was 56.8 degrees F while Valdosta reported 63.5 degrees F.

If the soil temperatures are not warm enough for seed germination, early seed plantings could rot.

The roots need to be actively growing to absorb water and nutrients.

If we plant and fertilizer summer vegetables too early we will be wasting fertilizer.  The plant roots simply can’t absorb it.  This fertilizer could get washed away, wasting your time and money. Also, this leached fertilizer could be problematic for our watersheds.

Determine your soil temperatures.

To determine your soil temperature at the 4 inch depth visit www.georgiaweather.net.  Click on the station nearest your garden.  Or, you can see a summary of soil temperatures across the state.

Soil Temperatures in Your Georgia Garden
Newly planted tomatoes. Waiting until the soil temperatures are warm enough is one step to success for your summer garden.

Remember the rule of thumb is play it safe and wait!

Happy Gardening!

Indoor Seed Starting – Part Two

All of this rain has me very excited about getting back to our seed starting project.

I have one note about seed starting media. If you choose to purchase bagged media for starting seeds indoors, do not choose something with fertilizer in the mix. This will be too strong for seedlings. There are plenty of bagged mixes specifically for seed starting so choose one of those.

We are ready to expand our pellets. Notice the seed pellets are fully expanded with no standing water:

Seed pellets are not too wet but moist all the way through.

Next, take a fork and open up the top a bit and fluff the media. I like to take this time to make sure that the moisture is uniform all the way through with no dry spots:

Fluff the planting media with a fork to ensure uniform moisture.

Now you are ready to plant your seeds. If you are mixing seed types in one tray, make sure that they will emerge and grow at about the same rate. I like to use plastic forceps to exactly place the seed where I want them. Some seeds, like lettuce and herbs, are very small and easily lost in the tray. Know how deeply to plant the seeds. Most of the ones you will probably plant just need to be lightly covered with the planting media.

Plastic forceps can be your best friend!

It is worth the effort to do some research on your seed types. For example, cilantro seeds don’t germinate easily when exposed directly to light. Also, there are some seeds that just do better planting directly into the soil, beans and corn are good examples.

At this point it is a great idea to label your seed tray. Sharpie markers on masking tape work well. The tape sticks to the tray but can be removed later. Do not be tempted to label the lid. You will be removing the lid later and you don’t want to forget the original orientation. Finally, put the lid on the tray, making sure it fits tightly.

Do not forget to label your seed trays.

Do not place your seed tray near a window and hope for the best. You will be disappointed. You will not get enough light for healthy seedlings and the temperature fluctuation at the window will be problematic.

Use a light system. The system does not have to be complicated. I have a light fixture with florescent bulbs attached to a structure with moveable chains. This setup was originally housed in a bathroom tub but it is now in my grown daughter’s bedroom. Very simple. You need the chain to move the light so it stays just above the seed tray. To produce robust seedlings you need the light no more than an inch or two above the tray. This will be imperative as the seeds germinate and grow.

If you are germinating seeds in a place that is reasonably warm you do not need a heating mat. Those were designed for outside greenhouses and places like Michigan. By using a heating mat when you don’t need one, you risk drying out your planting media.

So far this is pretty simple, right? If you have any questions or concerns you can comment or email me at beckygri@uga.edu. Send photos! Next week we will discuss seedling care.

Happy Seed Starting!

Indoor Seed Starting – Part One

Just flipping through one garden seed catalog I found 89 varieties of tomatoes, 21 varieties of cucumbers, 20 varieties of eggplant and 26 varieties of sweet peppers, including three types of lunchbox peppers. Compare that to the different types of vegetable plants that you would find at your big box retail store. Add some variety to your life and try starting your own seeds!

The rule of thumb is to start your warm-season seeds 6-8 weeks before planting time so over the next weeks we are going to explore indoor seed starting in-depth. For beginners, follow along with me as you start your first seeds. For seasoned seed-starting veterans, you may pick up a trick or two. I also encourage you to share your experience through the comments.

Let me begin by writing that there are many effective ways to start seeds indoors. I am going to share with you the way that I like to do it. I have been starting seeds indoors for decades and I have found a way that works best for me. You may find a different way that works best for you and that is terrific. I look forward to learning from you all as well.

To start, I like these re-useable plastic trays. They are easy to store and come in many sizes. I have friends who save their old plastic milk jugs and trim them down for seed starting; that works well for them.

These trays are easy to use for seed starting.

Any plastic trays MUST be disinfected before adding soil media and seed. I use a solution of 9-parts water to 1-part bleach. This step is important to eliminate any pathogens that have been overwintering on remaining soil particles. Starting with clean trays is an important step towards healthy seedlings. Don’t skip it.

These soil particles could hold pathogens. Disinfect those trays!

I like to use the peat moss discs for my planting media. As a bonus, the peat moss contains properties that discourage fungal growth. This helps prevent the disease damping off which is a real problem for seedlings.

The pellets expand with the addition of water.

These pellets are readily available and are easy to store. Add water and the pellets expand. I use warm water to create a favorable environment for the seeds. It is important here to not oversaturate the discs with too much water. Too dry is better for the seeds than too wet. Too wet means that the seeds could rot or disease will become a problem. You want the planting media to be just damp. If you can wring water out of the media, it is too wet. If this happens you can let the discs sit outside the tray for a few hours so that they can dry out a bit. You will get the hang of how much is too much as you practice.

Okay, gather your seed starting equipment, and play around with the pellets. Next week we will talk about planting the seeds.

Happy Gardening!

Is Your Garden a Winter Mess?

With the long-lasting cold winter temperatures and snow (snow!!) this winter how does your food garden look and can it be salvaged? According to Home Garden Vegetable Specialist, Bob Westerfield, we are better off just pulling up spent broccoli, cauliflower, cabbage and leafy greens. Leaving them in the garden creates a harbor for disease and insect pests. Brussel sprouts is an exception. If your Brussel sprouts look good, you can leave them and they may still produce.

A mushy winter mess!

Since playing in the garden is limited consider soil testing now and making your Spring garden plan. You will be able to plant new cool-season plants soon enough!

Happy Gardening!

Save the Date(s)

There are many fantastic events planned for 2018 so mark your calendars and save these dates:

Plant Sales – now!
4-H groups and Master Gardener Extension Volunteers across the state are having plant sales. These sales feature high quality plants for reasonable prices. While picking out your plants, find out what classes and workshops are being offered this year. Contact your county Extension office for more details.

Hands-On School Garden Day (Part of Ag Week) – Monday, March 19th
To kick-off Georgia Ag Week, Hands-On School Garden Day will recognize the importance of school gardens. Plan a special workday in your garden or use the day to remind your administrators and community members about the importance of your school garden. What makes your school garden special? We would love to see photos! Post them on the UGA Community and School Garden Facebook Page!

Healthy Soil Festival – May 5th at Truly Living Well Farm
This year’s Healthy Soil Festival will have some special activities for teachers and those who work in school gardens. Stay tuned for more details!

American Community Garden Association Conference in Atlanta – September 14th-16th
This year’s conference is in Atlanta! More details will be coming but definitely put those dates on your calendar.

Great Georgia Pollinator Count – August 2019
In August of 2019 gardeners across the state will be counting pollinators as part of a year long campaign to promote best management practices in getting and keeping pollinators in your garden! You will want to be a part of this! Again, stay tuned for more information as we get closer to 2019.

Do you have an event to add? Let us know!

Happy Gardening!

Deciding on Raised Beds or In-Ground Gardening

Dr. David Berle and Robert Westerfield of UGA have created a series of publications on community/school gardens.  One of the most popular circulars is Raised Beds vs. In-Ground Gardens.  It is an excellent resource when determining whether or not raised beds would work for your garden.

The height of these beds is helpful for the senior gardeners at Tobie Grant Manor garden.
The height of these beds is helpful for the senior gardeners at Tobie Grant Manor garden.

Raised beds are defined as elevated boxes that are manageable in size and are filled with enough soil to support plants without using the soil underneath the box.  The height of the boxes can vary.  Tall boxes can be very beneficial to senior gardeners who are more comfortable working while standing instead of knelling down.  When dealing with native soil of questionable quality, raised beds with imported soil are an easy solution.

Some other advantages of raised beds are:

  • Prevention of soil compaction- raised boxes can limit foot traffic on the soil
  • Less weeding and maintenance
  • Reduced conflict – raised beds are very defined and easy to assign to participating gardeners
  • Better drainage
  • Extended garden area – raised beds can be placed on slopes, compacted soil, and even parking lots
The in-ground gardens at Woodstock Community Garden make it easy for a tiller to work the soil.
The in-ground gardens at Woodstock Community Garden make it easy for a tiller to work the soil.

There are advantages to in-ground gardens.  Raised bed materials can be costly for a garden group just starting and in-ground gardening can allow a tractor or tiller to easily help prepare the area.  Other advantages include:

  • Use of existing soil
  • Less permanent – if the landowner deems the garden temporary or for good crop rotation
  • Easier irrigation
  • Less start-up work
  • Clay soils do have benefits that are not found in man-made soils

As you start, or change, your garden carefully consider which arrangement will work for your group.  Consider your current and future needs and decide how much time and resources you all are willing to commit.  Your local UGA Extension office is a great resource for help.

Happy Gardening!

The Magic of the New Year

Recently I attended a presentation given by a scientist who is known for her expertise in plant genetics. Her lab was one of the first to do work in what we now call genetically modified organisms (GMOs). Between the explanations of plant biochemistry and the future of our food system she snuck in a statement that was so profound it is worth sharing. She said, “plants are magic.” Yes, plants are magic.

One of my first memories involves plants. At about six years old, I received a science kit as a gift where seeds germinated in a substrate so that the grower could see the root radical and shoot as the seed sprouted. I was hooked. Plants were magic.

Basil seedlings

I have never lost that feeling of awe when dealing with gardens. Most of you are shaking your heads in agreement as you read this. The way flowers survive our droughts and our own mismanagement. The way a tiny seed pushes through our hard clay soil. How small seeds yield large amounts of food. You know it; plants are magic.

Savannah Trustess Garden

As we go into the new year and we are planning our 2018 gardens may we never lose that magic. I look forward to gardening with you in the next year.

Happy New Year!