Tomato Talk: Wilts and Tips for a Big Harvest

Nothing causes that sinking feeling like walking into the garden and seeing one or more tomato plants wilting. Not just some lower leaves that are yellowing, curling, or drying up from leaf spot diseases. No, I’m talking about healthy green leaves and stems that start to go limp. Oftentimes, this spells the beginning of the end for the affected plant(s) so it’s important to figure out what’s causing the wilting symptom. Even if you lose one or more plants this year you’ll want to prevent a recurrence next year. UME’s Home & Garden Information Center seems to be getting more tomato wilt questions this year than usual.

Wilting may indicate that roots or stems are injured, soil moisture has been too high or too low, or that the vascular tissue directly below the epidermis (skin) of tomato stems is blocked up with fungal or bacterial pathogens. Plants with disease-caused wilt should be removed. Here are some possible causes for wilted tomato plants in Maryland.

Fusarium wilt– this disease is caused by a soil-dwelling fungus. Lower leaves turn yellow and leaves and stems begin to wilt, often on one side of the plant. Leaves may revive overnight. Cutting affected stems lengthwise with a razor blade (directly below the surface) will reveal brown discoloration or streaking. The disease rarely infects all of the tomato plants in a row or a bed.

This fungus can survive in the soil for years even if the tomato is not grown in that location. One solution is to grow resistant varieties- look for those that are resistant to at least two of the three known races of fusarium wilt. Example:

Nature’s Bites F1: Fusarium Wilt 1, Fusarium Wilt 2, Fusarium Crown & Root Rot, Leaf Mold, Root Knot Nematode, Tobacco Mosaic Virus

Another option is to grow tomato plants in containers filled with compost and soilless growing media. Don’t set the containers on the garden soil that had the fusarium wilt problem last year. 

Continue reading

Growing wheat in Gaithersburg

Wheat sheaves hanging up on a stick to dry
Wheat sheaves hanging to dry. Photo: L. Davis

Wheat is in the news this year (recall export restrictions from Ukraine and India). We don’t usually think of wheat as a home garden crop, but it does grow well in this area.

In 2017, 2019, and 2021 I planted wheat on a small section of my community garden plot in Gaithersburg. I planted hard red winter wheat in late October in a 5′ x 7′ plot in full sun. Winter wheat needs about 8-10 weeks of growth before the ground freezes, at which time it should be about 5-6″ tall. Rows can be 6″ apart, so it also serves as a cover crop over the winter. I surrounded it with a rabbit barrier of chicken wire.

Full grown wheat
Full-grown wheat. Photo: L. Davis

In spring, the wheat grew to about 4′ in height and began to form kernels in May, and I encountered my first challenge – birds. Sparrows swooped in and started eating the young seed heads. Recycling some cicada netting over the top and draping it over the chicken-wire fence surrounding the wheat was effective for a while, but when the stalks began to mature and dry, the pesky little sparrows found ways to get in. I had to use clothespins to secure the netting to the chicken wire.

Harvesting wheat with a scythe
Harvesting the wheat. Photo: L. Davis

Harvest time was in early June. I found an old scythe in my community garden toolshed, sharpened it in my kitchen, and cut the wheat stalks about 18″ long. After gathering them into sheaves and tying each bundle with a shoestring, I hung them to dry for a couple of weeks. The second challenge was threshing.

There are lots of ideas on the internet for threshing; that is, removing the grain from the stalks. An ancient no-machinery method is to walk on the wheat heads, or hitch your animals to a circular contraption and have them walk around and around over it. We preferred a more sanitary way. Other methods repurpose bicycles and other machinery to release the grains. Or you can beat the stalks against the inside of a bucket. In my case, I put my husband to work bashing a pillowcase of wheat heads against the floor and then stomping on the pillowcase.

Next comes winnowing. I set a simple household fan on the kitchen counter and poured the wheat berries into another bowl in front of the fan. The heavy kernels dropped into the new bowl and the chaff, which was much lighter, blew away. (This required a major cleanup of my kitchen. It could definitely be done outdoors!)

To preserve the wheat berries, I packed them into jars and plastic containers and stuffed what I could into the freezer. When we are ready to make bread, I thaw a jar of the wheat and grind it with a NutriMill electric grain grinder. That does an excellent job, and I make bread using half whole wheat and half good quality white bread flour. Pass the raspberry jam!

Linda Davis is a Master Gardener living in Gaithersburg, Maryland. She completed the Master Gardener course in Virginia in 1997.

Do plants get food from the soil?

cabbage plant
Cabbage. Photo: A. Bodkins

People often say you have to feed your plants, but in reality plants make their own food through the process of photosynthesis, which yields oxygen and glucose. Glucose is the food that plants use for energy and growth, they don’t need us to actually feed them. Since plants can make their own food, they are called autotrophs.  The green pigments in plants, called chlorophyll, capture light energy from the sun. The process isn’t nearly as simple as I’ve described it. 

Plants can further be divided into two classifications, C3 or C4, which is determined based on how efficiently the plant can photosynthesize and whether the plant has to go through the process of photorespiration, which is required for C3 plants. This makes C4 plants, like corn, sorghum and  sugarcane more drought resistant because of the complex processes that occur within the plant at molecular levels. The majority of plants are C3 plants. For more information on this topic check out the article from University of Illinois, The difference between C3 and C4 plants

So why do plants need a soil that is sufficient in macronutrients and micronutrients if that is not their food?  Well, the short answer is that nutrients help plants grow and keep them healthy so that they can photosynthesize efficiently. As the plant mass increases, the plant leaf size/surface area increases, which allows the plant to capture more sunlight and turn it into more food.  

You can check out the Home and Garden Information Center’s webpage about fertilizer to learn more about macronutrients and micronutrients. Macronutrients are those elements that the plant needs the most of to be healthy. Water provides hydrogen and oxygen. Carbon dioxide provides oxygen and carbon which are part of the required macronutrients for all plants. The remaining macronutrients are provided by soil (unless the plant is being grown hydroponically, of course). Plants can only take up or use nutrients that are dissolved in soil water. This is why it is so important to make sure that your soil gets sufficient water. Some plants are called heavy feeders and this is generally in relation to their need for larger amounts of the macronutrients, especially nitrogen. Some examples are tomatoes, everything in the cabbage family, and beets.  The University of Maryland provides more information on fertilizing vegetables.  

By providing an optimum growing environment, through correct amounts of light, moisture, and nutrients, the plant will have the best chance at reaching its full potential. As I eagerly wait for the first produce from my vegetable garden this season, I want to be sure that all my plants reach their full potential and produce a large amount of food for me and my family to enjoy this growing season. 

Please comment below with what you are doing this year to ensure that your plants are healthy and happy and growing well. Do you test your soil every 3 years or whenever you are planting a garden in a new area?  Do you research the plant needs (full sun, part sun, or shade) before planting? What questions do you have about managing soil fertility and nutrients? 

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.


This year, the University of Maryland Extension Master Gardener Grow It Eat It Program celebrates the resource that supports all life on earth – soil! Look for soil education programs offered by your local Master Gardener program, and visit the Home & Garden Information Center website for more information about soil health.

2022 is the year of soil health

Heat-tolerant greens

Tender spring lettuce and spinach leaves are just a memory for many Maryland gardeners. As we move into the summer season the types and flavors of garden greens expands significantly. While some, like Swiss chard and kale, can be cut or torn and dropped into fresh salads and dishes, most will benefit from some level of cooking, like sautéing on their own or being added to stovetop or baked dishes. Most of the summer greens below grow quickly and have a long harvest period. They help us improve food security and adapt to climate change.

General growing tips for summer greens:

  • Water, water, water and fertilize to promote rapid, healthy growth and  maintain leaf and stem succulence
  • No row cover! They can cause a heat build-up. Instead, use insect netting to exclude insect pests
  • Plant summer greens in containers and move them to shady spots close to your front or back door 
  • Create some shade for lettuces and other marginal crops like cilantro … plant on the north side of taller crops or try 30% to 50% shade cloth material 
  • Most leafy greens below can be treated as cut-and-come-again crops: they put on new growth below each harvesting cut. Older, stressed foliage is less palatable
  • Explore seed racks and online seed catalogs for heat-tolerant crops and varieties

Leafy amaranth

Two well-adapted species for Maryland gardens are Amaranthus viridis (callaloo, also known as slender amaranth) and Amaranthus tricolor (Chinese spinach; leaves somewhat smaller than A. viridis).

Several species are very popular in Central and South America, India, Southeast Asia, and Africa. Nutritionally, they compare favorably with spinach and Swiss chard. Plants in this family use a special C4 photosynthetic pathway, also present in corn and sugarcane, which allows for vigorous growth under hot, dry growing conditions. 

Leafy amaranth is basically a tasty and productive pigweed. Flowering accelerates with shorter days after the summer solstice. Frequent harvesting delays flowering and promotes branching. Immediately remove any flower stalks that emerge to prevent re-seeding.

Callaloo growing in 3-gallon bags in a high tunnel. UME Small Farms Program
Photo credit: Jon Traunfeld

Callaloo can quickly become a weed problem. Don’t let plants flower. Each plant can produce >100,000 tiny seeds dispersed by water, wind, tools, and animals. Photo credit: Jon Traunfeld

Tri-color amaranth. Photo credit: Jon Traunfeld

Other heat-tolerant greens in the Amaranthus family:

Swiss chard and Perpetual Spinach (a.k.a. leaf beet) fall within the beet species- Beta vulgaris- and will produce large amounts of leafy goodness from spring through early fall. Orach (Atriplex hortensis) is another family member that grows best in spring and fall but can tolerate summer heat.

Two varieties of Swiss chard in the UMD Community Learning Garden. Photo credit: Jon Traunfeld

Leafy Brassicas

Several crops in the Brassicaceae plant family tolerate Maryland summers. Collard plants produce reliable and abundant harvests from summer through fall. ‘Morris Heading’ is an heirloom “cabbage-collard” variety found in Baltimore City community gardens throughout the growing season. ‘Green Glaze’ is touted as being heat-tolerant but I am not aware of studies that looked at temperature effects on the productivity of collard varieties. 

Collard plant in late July surrounded by common purslane, and edible weed. Photo credit: Jon Traunfeld

Mustard and kale are somewhat less heat-tolerant than collards. ‘Green Wave’ and ‘Red Giant’ mustards and ‘Lacinato’ kale are common varieties grown in summer gardens in Maryland. I’m very curious about Portuguese kale (Couve tronchuda). It resembles collard and is described as sweet and tender and more heat-tolerant than other kales. If you grow it please leave a comment about your experience.

‘Lacinato’ kale (a.k.a Tuscan kale, dinosaur kale, black kale) growing in Baltimore City in late July. Leaves are harvested from the bottom. Photo credit: Jon Traunfeld

Check seed catalogs for mild-flavored leafy Asian greens that hold up well in warm weather like Tokyo Bekana (Brassica rapa var. Chinensis), ‘Komatsuna’ (Brassica rapa var. perviridis), Vitamin Green and Tatsoi (Brassica rapa Napa group), and ‘Chijimisai’ (tatsoi x komatsuna). 

Malabar spinach

Basella alba (green stem) and Basella rubra (red stem) below are “summer spinaches” that produces a vigorous leafy vine. Leaves and stems can be sautéed or used to thicken soups and stews.

New Zealand spinach

New Zealand spinach (Tetragonia tetragonoides) below is a low growing annual with a spreading habit that has somewhat fuzzy, arrow shaped leaves, and mild spinach flavor.

Photo credits: Jon Traunfeld

Molokhia (Corchorus olitorius), known as Egyptian spinach and jute leaf, is an important food plant in the Middle East, Africa, and Asia. It’s higher in vitamins and minerals than most other leafy greens. This is the jute plant, known for its strong stem fibers. Young leaves can be eaten fresh, sautéed, or used to thicken soups and stews.

Sweet potato (Ipomoea batatas) – shoot tips, young leaves, and tender stems are excellent in many top-of-the-stove dishes. Harvesting young foliage, even on a regular basis, will not reduce your harvest of sweet potato roots later in the season.

Sweet potato plants with a less typical cut-leaf shape. Photo credit: Jon Traunfeld

Hibiscus as a Leafy Green?

Sunset hibiscus (Abelmoschus manihot) and roselle hibiscus (Hibiscus sabdariffa) leaves have a compelling lemon-sour flavor similar to garden sorrel. These plants are in the Malvaceae family along with cotton and okra, planted throughout the tropics and sub-tropics. Roselle is also grown for its strong fibers and its fleshy calyx which farmers and gardeners use to make tea, juice, and preserves.

Green stem hibiscus plant harvested for its leaves used in many Indian foods. 
Photo credit: Jon Traunfeld

Don’t Dismiss the Lettuces!

Lettuces are generally a cool-season crop but these varieties have demonstrated some level of heat tolerance:

‘Merlot,’ ‘Speckled Bibb,’ ‘Adriana,’ ‘Jericho,’, ‘Coastal Star,’ ‘New Red Fire,’ ‘Starfighter,’ ‘Tropicana,’ ‘Red Cross,’ ‘Magenta,’ ‘Cherokee,’ ‘Green Star,’ ‘Summer Crisp,’ ‘Little Gem,’ ‘Muir,’ ‘Burgundy,’ ‘Bronze Beauty,’ ‘Forlina,’ and most oakleaf types of leaf lettuce. Asian sword leaf lettuces, (pointed lettuce) have long, thin leaves and are described as crisp and tender with a mild bitterness.

One of the sword lettuces growing mid-summer in a Howard Co. community garden. Photo credit: Jon Traunfeld

An Auburn University study found that ‘Aerostar’, ‘Monte Carlo’, ‘Nevada’, ‘Parris Island’, ‘Rex’, ‘Salvius’, and ‘Sparx’ grown in a “hot greenhouse” out-performed 10 other heat-tolerant lettuce cultivars and received the highest flavor and texture ratings.

Give some of these greens a try this summer. The investment in seed, space, and time is minimal and you may discover some surprising new textures and flavors.

Resources:

Callaloo recipes– Dr.Nadine Burton, Alternative Crops Specialist, UMES Extension

The Difference Between C3 and C4 Plants– University of Illinois

The Heirloom Collard Project collects and increases collard seed and documents the history of many American South varieties 

Malabar spinach, Basella alba. University of Wisconsin

Lettuce All Year in a Changing Climate– Sustainable Market Farming- Pam Dawling

World Vegetables: Principles, Production, and Nutritive Values. V. Rubatzky, M. Yamaguchi. 1997

By Jon Traunfeld, Extension Specialist, University of Maryland Extension, Home & Garden Information Center.

Read more posts by Jon.

Q&A: Why do my cucumber and zucchini plants wilt?

One Spotted and multiple Striped Cucumber Beetles, feeding on overripe pumpkin. Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

Q: Last summer I had cucumbers and zucchini wilting and dying even though I’m pretty certain I didn’t have root rot or squash vine borer. What should I try this year so I can hopefully get a harvest?

A: Bacterial wilt disease, transmitted by cucumber beetles is the prime suspect for crop failure in this instance. Both of these garden pests – Striped Cucumber Beetle and Spotted Cucumber Beetle – are native to North America and can cause serious damage to vegetables in the squash/cucumber family, though they can also feed on unrelated fruits, vegetables, and ornamental plants.

Although their feeding causes direct plant damage, the main issue comes from their introduction of one or more plant pathogens. These beetles can transmit diseases like bacterial wilt and viruses, none of which are curable.

Delaying the planting of squash and cucumber transplants until mid-June may evade the host-seeking adults. Until they bloom, cover plants with insect netting or row cover (the former is ideal as it doesn’t trap heat). Bees will need to reach the flowers for pollination, but once the fruits start to develop, plants tend to be less susceptible to infection. Since more than one beetle generation can occur per year, clean-up veggie garden debris in autumn to deny remaining adults overwintering shelter.

For now, ‘County Fair’ is the only available variety resistant to bacterial wilt. This pickling cucumber is parthenocarpic– it produces mostly female flowers that don’t require pollination to set fruit. The Cucumber Beetles page at the Home & Garden Information Center has more information about these insects and their management.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun. Read more by Miri.

Send home gardening questions to Ask Extension at the Home & Garden Information Center

What is soil pH and does it really matter to plants? 

Well, the short answer from a soil nerd (please note soil nerd is not the same as a soil scientist or soil chemist) is that yes it really does matter! Have you ever done the experiment with boiling red cabbage leaves and used that as a pH indicator? It’s a fun science experiment but probably wouldn’t work for determining an accurate soil pH. 

People do not always see the benefit of getting their soil tested; however, if you take a good comprehensive soil sample, the information that you get from the analysis is invaluable. Not only will the results keep you from over-applying nutrients, which has economic and environmental benefits, but also it will ensure that your plants have all that they need right at their root tips.

In my opinion, the most helpful piece of information gained from conducting a soil analysis is the soil pH. PH is a measure of hydrogen ion concentration and tells you how acidic or basic/alkaline the soil is. Most vegetable garden plants prefer a pH between 6-7; therefore, acidic soils need to be amended with calcium carbonate (limestone). Acidic soils are indicated with numbers below 6 on the pH scale which ranges from 0 to 14. Soils in the Eastern US are often acidic, but the natural pH will depend on parent material and other soil factors, such as how the soil has been managed, what plants are growing there, etc. 

It should be noted that some plants actually prefer acidic soils, such as rhododendron, azaleas, and blueberries. Also, some plant diseases, such as scab in potatoes, are worse at a higher pH. Lowering soil pH (often done by adding sulfur) can take several months and may need to be a multi-step process. It is a great idea to test garden soils in the fall, so pH-altering amendments have time to do their job. Here is a great cheat sheet to help you understand what your soil analysis results mean

Another reason that pH is important is that it helps determine the availability of soil nutrients. Soil pH is linked to Cation Exchange Capacity (CEC), which is influenced by soil particle size and the type of parent material (rock). Clay soils will have a higher CEC (sites to hold onto nutrient ions) than sandy soils. CEC will be reported on most soil analyses. If the pH is not in the correct range, then many nutrients are not available to plants, even if you have applied ample nutrients. Thus, in order for the nutrients to support plant growth, it’s important to get that pH correct! This will provide both economic and environmental savings. Check out this link for a neat chart showing nutrients available and pH

The third reason that it is important to check pH is because it can affect soil microorganisms, which are going to thrive at a near neutral level. If the pH is too high or too low you will see a decrease in the number and activity of good soil bacteria, fungus, and more that help to break down organic matter and do amazing other things in the soil profile. (For more details on this topic, download PDF – Soil Acidity Impacts Beneficial Soil Microorganisms, from Washington State University Extension.)

Common questions about soil pH

Can pH change from year to year?

Some forms of nutrients —commercial fertilizers, compost, composted animal waste (cow, horse, pig, chicken manure), organic matter, the weathering of rocks, and even rainfall can alter pH. Fertilizers, depending on the type used, will alter soil pH at different rates. Refer to this PDF – Fertilizers and Soil pH from the University of California.  

Can I use a home soil Testing kit?

I normally steer people away from these types of kits, just because there are so many inaccuracies, especially,  if the kits were not stored at the proper temperature and the directions are not followed correctly, then the results may not be 100% accurate.  

What about electronic soil testing probes?

I don’t have first-hand experience with these probes. I am sure that they do have a level of accuracy; however, I cannot justify the upfront cost. For most gardeners, soil testing every 3 years is sufficient, so in my opinion, it is easier to just collect the sample and send it to a laboratory. 

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland, edited by Christa Carignan, Coordinator, Home & Garden Information Center, University of Maryland Extension. See more posts by Ashley and Christa


This year, the University of Maryland Extension Master Gardener Grow It Eat It Program celebrates the resource that supports all life on earth – soil! Look for soil education programs offered by your local Master Gardener program, and visit the Home & Garden Information Center website for more information about soil health.