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Rockwall County Master Gardener Spring 2022 Newsletter

In this issue...

All about tomatoes


Growing cut flowers

Ask a Master Gardener

Vegetable planting guide

Our Favorites


Upcoming events


Featured articles

All about tomatoes

If a tomato plant could have a "Wish List" it would include well-drained soil with lots of organic matter, balanced fertilizer, full sun and routine watering. Before we talk about how to grow tomatoes, let’s first talk about how to choose the tomato plant that’s right for you.

Determinate and Indeterminate

Determinate tomato plants are smaller and do well in containers. Their fruit ripens earlier and around the same time. You will get one harvest of tomatoes before the plant dies. Indeterminate tomato plants are bigger and can grow higher than 6ft tall. They need staking or cages and will continue to grow and produce fruit until unfavorable weather conditions or frost occur.

Hybrid and Heirlooms

Hybrid tomatoes are specifically bred for desirable characteristics. Hybrids often have favorable traits, such as disease resistance, easier care, higher yield and uniform appearance. Heirloom tomatoes have not been cross-pollinated with other varieties and come from seed that has been handed down through generations. They have robust flavor and unique appearances but may have less predictable growth habits.


There are a lot of varieties of tomatoes to choose from ranging in size, shape and color. Click here for a list of recommended varieties in our area. When thinking about the size of tomato, keep in mind that larger tomatoes can struggle in North Texas. They may not have enough time to finish growing before the summer heat sets in.

When to plant

We are lucky to have two growing seasons for tomatoes, the spring and late summer. For spring, plant tomato transplants in mid-March but be prepared to cover them for a night or two if we get any last-minute freezes. For a fall harvest, plant tomato transplants around late July, early August (about 100 days before the first expected frost). The first fall frost in our area occurs around November 17th.

How to grow

Choose a location that offers at least 6 hours of full sun each day. Raised beds are great for growing tomatoes. They warm up faster in the spring and allow for good drainage and quality soil. Transplants, instead of seeds, are recommended because of our short growing season. For best results, gently remove the lower 1/3 of leaves and plant with the lower 1/3 below the soil. This will encourage the lower stem to grow roots, making your plant stronger and more fruitful. Apply 2-3 inches of mulch around plants and install cages or stakes now to avoid disturbing roots as the plant grows. Choose a balanced fertilizer such as 10-10-10 and fertilize prior to planting and again when the first fruits set. Continue to fertilize every 3 to 4 weeks following the directions on the label. Water tomato plants slowly and deeply to help them develop a strong root system.


There are many diseases that can affect tomato plants at all stages of growth. Check the Plant Disease Handbook for a list of tomato diseases. Both synthetic and organic pesticides are available and cultural practices such as variety selection, mulching, fertilizing and regular watering can be used to help grow healthy, beautiful tomatoes.


In our last issue we discussed the disadvantages of using ‘weed and feed’ (a combination of herbicide and fertilizer) products for your lawn. It is safer for your trees, ornamentals and turfgrasses to fertilize and treat for weeds separately with the appropriate product and at the recommended time for each product. We touched on herbicides in the last issue and now we will discuss fertilizer. 


Fertilizer is often misunderstood and misused. Fertilizer is not “food.” Plants produce their own food in the form of sugars through photosynthesis. The minerals or nutrients supplied by fertilizer provide the ingredients needed for photosynthesis and growth. When minerals are lacking or absent in the soil, fertilizer can be added to maintain an adequate supply. It's not always necessary to fertilize your plants or lawn. Plants have varying nutrient needs depending on the species, the age of the plant, and its location. The amount and formulation of fertilizer to apply depends on soil test results, grass species and mowing practices, tree or shrub vigor, and environmental conditions.


A soil test will provide information on the availability major nutrients. Some soils contain phosphorus and/or potassium in amounts adequate for the maintenance of turfgrasses. Additional applications of these nutrients through fertilization will not improve the quality of the lawn. However, grass growing on soils deficient in one or more of these nutrients will respond well to fertilizers containing these nutrients. To learn more about soil testing, click here.


Mowing practices, such as regular removal of grass clippings and constant same directional mowing, often adversely affect lawn health. Environmental conditions such as shade, soil type, and rainfall also influence fertilization requirements. Moderately or heavily shaded areas should not be fertilized as much as areas in full sunlight. Grass growing in shade is generally less hardy, contains more water, and has a weaker root system than grass growing in full sunlight. Fertilizer tends to make the grass retain more water and increases its susceptibility to disease, drought and other stressors.


It is important to determine the cause of the problem before attempting to correct it with fertilizer. Fertilizer should not be considered a cure for ailing plants when unadapted or unhealthy plants are chosen, carelessly planted or improperly watered. When fertilizing trees and shrubs, keep in mind: Fertilizer is beneficial when it is needed and used properly in the right amount, at the right time, and in the right place. The following articles, Lawn Fertilization in Texas and Fertilization for Texas Warm-Season Grasses, provide recommendations for when and how to apply fertilizer to your lawn.


Growing cut flowers

Imagine coming home every day to a house filled with fresh flowers. Even better, imagine the feeling of knowing that all those fresh flowers came from your own backyard. Good news! That dream can easily become a reality, even in our challenging North Texas climate. All you need is a bit of preparation and the right kind of flowers. First, plant a lot. It takes more than a few plants to harvest a bouquet of flowers. Succession-sowing ensures a constant supply of flowers throughout the growing season. A common interval for successive plantings is 2-3 weeks. 

Zinnias, sunflowers, cosmos, and gomphrena are good candidates for succession-sowing. The flower transplants available in garden centers are usually intended for bedding or containers. For the best results, select flower varieties that are specifically bred for cutting and plant them yourself from seed. Consider these cut flowers that can be successfully grown at home in North Texas:


Zinnias are one of the easiest flowers to grow in North Texas gardens. With excellent heat and drought tolerance, zinnias will bloom continuously from spring through fall. Even better, the more you cut, the more they grow. Zinnias are typically direct sown in the garden once all threat of frost has passed (late March, early April). To grow zinnias for cut flowers, pinch the plant back by 1/3 once it is 12″ tall. This encourages branching.

Gomphrena (Globe Amaranth or Bachelor Buttons) is a longtime cutting garden favorite for North Texas. One of the toughest plants you’ll ever find, gomphrena is an annual that powers through our summer heat and blooms continuously until frost. Gomphrena can be planted in the garden anytime between late March and early September. For best color and vase-life, harvest when colored but before fully open.


Sunflowers - The happiest flowers of all, sunflowers are incredibly easy to grow. Sow seeds directly into the garden once all chance of frost has passed (late March). For continuous harvest, sow sunflowers seeds in succession every 2-3 weeks. For the best cut flowers, try growing single-stalk sunflowers. To ensure the longest vase life, cut sunflowers when they first start to open. Change vase water daily.


Rudbeckia (Black-eyed Susans) might not be an obvious choice for a cut flower, but this reliable perennial is now available in several interesting and eye-catching varieties. Rudbeckia hirta and Rudbeckia triloba are best for cut flowers.

Cosmos are one flower that truly thrives on neglect. It likes poor soil, zero fertilizer, and barely any water. Over-watering and over-fertilizing are the two most common reasons cosmos fail. Cosmos take well to succession planting, so experiment with multiple sowings. Start planting seeds in early April. Then start another batch of seeds in May for a fall harvest. Cosmos really love the fall weather in North Texas. Harvest flowers frequently to encourage a constant bloom.

Ask a master gardener

How do I treat fire ant mounds in my yard?

Fire ants are best controlled using a 2-step process involving a slow acting, low toxin broadcast bait (applied across your entire yard) and a fast-acting pesticide for individual mound treatment.

First, apply a fire ant bait over your entire yard between late August and mid-October. Baits contain food plus insecticide and contain a low amount of toxins. Worker ants take the bait back to the colony, where it is shared with the queen. The queen either dies or becomes infertile, which will lead to the eventual death of the colony. Always use fresh bait, apply when the ground is dry and no rain is expected for the next 48 hours. Apply in late afternoon/evening when worker ants are actively foraging. Baits can be applied anytime during the warm season and only need to be reapplied once a year. Be patient, baits are slow acting and can require weeks or months to work but are an essential step in controlling fire ant populations year-round.

For the second step, apply a fire ant insecticide directly to the mound for fast treatment of the colony. Closely follow directions on product labels. Ant deterrent products may cause the fire ants to relocate to another area in your yard or if the ants are nesting deep in the mound, treatment may not reach them. The best overall method is to use a yearly broadcast application of fire ant bait, followed by individual mound treatment when need. 

Spring vegetable guide


Don’t rush planting outside! Our last frost is around March 15th, but North Texas loves to throw weather curveballs so keep a watch on the forecast before planting (especially tomatoes and peppers). You can still plant cool season vegetables such as Greens (Collard or Mustard), Scallions, Lettuce, Spinach, Carrots, Beets, or Turnips.

Seed: Beans (Lima, bush, pole, snap), Greens, Scallions, Spinach, Cucumbers, Squash, Zucchini, Cantaloupe, and Melons.

Transplant: Tomatoes, Peppers, Broccoli, Squash, and Zucchini.


If you didn’t start in March – no worries! There is still plenty of time to plant veggies. If you want fall Pumpkins or Gourds, plant them now! Once your seedlings are well established, don’t forget to mulch your garden beds.


Seed: Beans, Corn, Cucumbers, Squash, Melons, Zucchini, Okra, Pumpkins, and Gourds.

Transplant: Peppers, Cucumbers, Squash, Melons, Zucchini, Okra, Eggplant, Pumpkins, Gourds, and Sweet Potato Slips.


Be sure to complete all major plantings before the heat really sets in at the end of the month. Okra really takes off in the hot weather. This is also a great time to begin your fall garden by starting tomato, eggplant, and pepper seeds indoors for fall transplant.

Seed: Corn, Cucumbers, Squash, Melons, Zucchini, Okra, and Black-Eyed Peas.

Transplant: Peppers, Cucumbers, Squash, Melons, Zucchini, Okra, Eggplant, and Sweet Potato Slips.



Annual herbs can be started by seed or transplant after the danger of last frost has passed. Once plants are established, harvest regularly. You can preserve cuttings for later by drying, freezing, or even propagating the cuttings for additional plants. If you buy refrigerated herbs from the grocery store and don’t use them all, use those cuttings to propagate more!

A few popular herbs that do well in Rockwall County include: Basil, Thyme, Oregano, Sage, Chives, Parsley, Cilantro, Lemon Balm, Mint, Lavender, Dill, and Lemon Verbena.

Click here for a full list of vegetable planting dates and visit the Texas vegetable gardening guide for more information. 

Our favorites!

What do we grow in our home gardens?


“Supertunia petunias are a favorite! They are sun loving and survive our oppressive heat. The amount of flowering makes them worth planting several pots each year. Fertilize and water regularly for the best show.”

                                - Suzan S.


Upcoming events...

Come see us at the Rockwall Farmers Market every 2nd and 4th Saturday of the month! May thru September 8:00 am to 12:00 pm at the Rockwall Downtown Square.

Please take our short Rockwall County Master Gardeners Survey to help improve our educational outreach.

Wednesday Gardening Hot Line: “Ask a Master Gardener!” Volunteers will be answering calls and emails every Wednesday from 10:00 a.m. until 12:00 p.m. Call (972) 204-7660 or email us anytime at:

Join Our E-mail List
Have you visited our booth at the Rockwall Farmers Market?
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Contact us

Rockwall County Master Gardener Association

915 Whitmore, Suite B

Rockwall, Texas 75087

972-204-7660 | | website


Michele Campbell, Editor

Contributing Writers: Cathy Grinstead, Janie Squier, Kim Townsend, Laura Wheelis,

Todd K. Williams

EnviroSmart is published by: Rockwall County Master Gardener Association part of Texas A&M ArgiLife Extension Service, the Texas A&M University System. The information given herein is for education purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by Texas A&M AgriLife Extension is implied.

Todd Williams - County Extension Agent

Ag/ Natural Resources


Texas A&M AgriLife Extension provides equal opportunities in its programs and employment to all persons, regardless of race, color, sex, religion, national origin, disability, age, genetic information, veteran status, sexual orientation or gender identity. The Texas A&M University System, U.S. Department of Agriculture, and the County of Commissioners Courts of Texas Cooperating.

Online resources:

Texas A&M Horticulture

Texas Master Gardener

Rockwall County Master Gardeners