Successfully growing tomatoes is an endeavor that is definitely worth the effort. Tomatoes are the most popular home gardening plant as nearly everyone dreams of the perfect BLT, the big plate of insalata caprese, or just a big bowl of tomato wedges with a sprinkling of salt on a warm summer afternoon. In order to give yourself the best chance of having these delicacies, you need to follow a few basic tenets that will make your garden grow. The following are things I have learned from growing heirloom tomatoes in Kansas City for the past decade…I hope they help you in your garden.
* Sunshine—Tomato plants need as much sunshine as possible in order to get the energy they need to grow and thrive. Tomato plants need a minimum of 8-10 hours of direct sunshine each day. Planting them in a shady part of your garden is one of the worst things you can do. Measure the amount of sunshine in your garden by placing a stick in the ground in the morning when the sunshine first hits the ground. Then go out in the late afternoon and place another stick where the last rays of light hit the ground. Mark the times for the beginning and ending of direct sunlight. If you don’t have at least 8-10 hours in this spot, do not plant tomatoes here. Find other locations in your yard that meet these sunshine requirements or break out the chainsaw and trim some trees to open up your garden to the sun. If you have a choice of morning sunshine or afternoon sunshine, go with the morning sunshine so the plants get dried off earlier in the day to avoid fungal issues. Late afternoon/early evening shade is actually beneficial to tomato plants.
* Soil—Growing tomato plants in infertile soil is a very common mistake a lot of gardeners make. Your soil needs to be amended each year to replace the nutrients that were removed by plants the previous year. Adding 3-6 inches of good compost each year and tilling that into the existing soil is the best way to maintain the nutrients your tomato plants need. I purchase quality compost from Suburban Lawn and Garden and have them deliver it by the dump truck load each year to ensure I have enough for all of my garden beds. You can make your own compost also, but make sure it has fully broken down into a sweet smelling, dark black, fluffy consistency before adding it to your gardens. Other amendments you can add to your soil are cotton burr compost, pine bark fines, composted manure (don’t use too much of this!), mushroom compost, or earthworm castings. No matter what you use, make sure you add a sufficient layer of 3 inches or more and work this into the soil with a tiller or a shovel or pitchfork. I like to add the compost at least 2-3 weeks before I plant my tomato plants to allow the nutrients to blend together and become available for the young plants.
* Plant Selection—Selecting healthy tomato plants for your garden is a crucial step for the successful tomato garden. You want to purchase a plant that is between 6-10 inches tall, very stocky, and has a dark green color to the leaves and maybe some signs of purple in the stem and leaves. Avoid buying plants more than a foot tall or ones that have light green colored leaves. Plants that are light green have likely been grown in a hothouse environment and have not been adapted to our climate. Plants that show some purple coloring in the stems and leaves have been exposed to cool, spring weather and are prepared to adjust to your garden very quickly. Very tall plants have not been exposed to winds or were started way too early to be grown here in Kansas City. Buying a very tall plant or one that has blossoms or even fruit already set on it may get you an early tomato, but you won’t get many of them and the plant will not be healthy enough o survive our summer. The expense of these large plants is not worth it. Buy a plant that is short and stocky and you’ll have a much healthier and productive plant that will crank out tomatoes all summer and into fall.
* Timing—The best time to plant tomatoes in the Kansas City area is the first two weeks of May. By the first week of May, we are mostly out of danger of frosts (keep an eye on the weather until June though!), the soil temperatures have usually warmed into the low 50’s, and the angle of the sun and length of daylight are optimal for rapid root development during the first few weeks after planting. If you plant too early, you run a high risk of frost (any frost will kill tomato plants), the soil temperatures are too low and the plant will not grow vigorously resulting in a high chance of it catching a disease, and the length of sunlight time isn’t enough to get the plant’s roots growing rapidly. The month of May should be for tomato plant root growth, and then it can grow lots of foliage and set fruit in June for ripe tomatoes in July and August. If you plant too late in May, the plant may not be big enough to set fruit before the high heat of summer gets here. Tomato plants do well in temperatures in the 90’s, but will not set fruit when the temperature is much higher as heat above 92 degrees will kill tomato pollen. Planting in the two week window at the beginning of May is your best bet for a consistent, healthy, and heavy crop of fruit.
* Space– Tomato plants start out small and it is tempting to plant them close together to get as many as you can in your garden. Despite their diminutive size early on, most tomato plants can grow to 6-12 feet tall with a diameter of 3-4 feet or more. At the bare minimum, you should provide at least 2 feet between each plant, but 3 or 4 feet is optimal spacing. Giving plants plenty of room to grow keeps them from competing with their neighboring plants for nutrients, water, and sunlight. Plants spaced too close together are also highly susceptible to fungal diseases in our humid Kansas City summer weather. Giving them plenty of space allows the air to circulate between them and greatly reduces fungal problems. There are some tomato plant varieties that grow smaller and can be planted closer together such as the bush and dwarf varieties. These types can also be grown in large containers that re 5 gallons or more in size. Contrary to popular belief, cherry tomato plants can grow much larger than many other types. Some cherry tomato plants can grow to 12-15 feet or larger, so give them plenty of room to grow!
* Support– When I was a child, we grew our tomato plants in the ground and let them sprawl across the garden. We would place lots of straw under the vines to keep them off of the soil. This was a good method for growing tomatoes, but we lost a lot of fruit to slugs, rodents, and clumsy feet in the garden. Supporting your tomato plants and growing them vertically is a far superior method of growing tomato plants in the home garden. Tomato plants grown vertically can be grown closer together, have less damage from animals, and are less susceptible to fungal diseases. A fully grown tomato plant with fruit can weigh 30 lbs or more, therefore they need a very sturdy support system to keep them from collapsing. Concrete mesh cages anchored with 6 foot T-Stakes or Texas Tomato Cages are my preferred method of supporting tomato plants. Do not use the flimsy, conical cages they sell at the big box stores as the plants will bend them like a paperclip the first time the wind blows. A sturdy, 8 foot long 2” x 2” stake driven into the ground will support a tomato plant as well, but you’ll have to tie it to the stake several times as the plant grows taller in the summer. Cages are more expensive, but require a lot less plant maintenance and support the largest of plants very well. Investing in sturdy cages is a good place to spend your gardening dollars.
* Water– Tomato plants originated in the dry regions of present-day southern Mexico and northern Central America. This region’s climate ranges from somewhat arid to sub-tropical in nature. Therefore tomato plants are genetically adapted to grow in areas with little water and high heat. One of the biggest mistakes that tomato growers make is over-watering their plants. Tomato plants grown in rich, deep soil only need to be watered at most every 5-7 days. If you plant them deeply and water them in thoroughly after planting, you can water them even as little as every other week even in the hottest and driest of seasons. Tomato plants deprived of water will send down deep roots to tap into sub-soil moisture and will grow very well and produce fruit that has more intense flavors. Tomatoes that are planted shallowly and watered too often will have a weak and shallow root system and depend on frequent watering to survive and the ripe fruit will have a weaker, watered down flavor. Many growers “dry farm” their tomato plants and do not water them at all after the initial watering right after they plant or maybe only water them once or twice during the entire summer. When you do water your tomato plants, make sure that you water them deeply…at least 1-2 gallons per plant and then allow the soil to dry out considerably before watering again. I prefer to use drip irrigation to water my plants as this conserves water and delivers a precise amount directly to the roots of the plant. Whatever method you use, do not water the foliage of tomato plants…water only the base of each plant to keep the leaves from contacting fungal diseases.
* Mulch– Tomato plants like their tops hot and their bottoms cool. Use some sort of mulch to retain moisture in the soil and to keep the soil cooler. Straw, grass clippings, and even newspaper are good mulches. Just make sure they are several inches thick and that they do not actually touch the stem of the plant. I personally prefer to use silver plastic reflective film as a mulch. The plastic stops the soil from drying out and almost completely eliminates weeds. The silver reflective film is excellent insect control as it bounces light under the leaves and keeps insects from finding a shady spot to munch on your plants. The film has to have direct contact with the soil or the soil will never warm up. I’ve used the red and black plastic films before, but far prefer the silver for its insect scaring properties…plus, your gardens look really cool from Google Earth!
* Fertilizing – Even well amended soil doesn’t have everything a tomato plant needs to grow as many fruit as possible. A fertilizing schedule is essential to give the plants some extra nutrients to do their best all summer long. Look for a fertilizer that is relatively balanced such as a traditional 10-10-10, or 12-12-12, or something like Tomato Tone which is 3-4-6. Avoid using any fertilizer with high nitrogen content imbalance such as Miracle Grow 12-4-8 as this will cause you to have lots of green leaves, but very few fruit. At planting time, I like to add some Bone Meal 4-12-0 for an added phosphorous boost. I fertilize when I plant, then again when the first fruits start to set. After that, I fertilize every 2 weeks until the end of summer. I personally use a fertilizer injector with my drip irrigation system, but you can also side-dress with granular fertilizer or mix the fertilizer and water the base of each plant. Try not to let any granular fertilizer touch the stem of the plant as it may burn them.
* Organic?? – Staying purely organic is a great idea, but sometimes it is impractical or may cause you to lose your crop of tomatoes. I try my best to stay away from using chemicals and each year I use fewer and fewer. Back in the day, I applied Sevin dust like there was no tomorrow. I rarely use any insecticides any more other that a spray of insecticidal soap to spot treat any aphid infestations that may pop up. I do have a regimented use of a fungicide. I use Daconil which can be found in the product, Ortho Garden Disease control. It is a very safe product from what research I have found and it keeps the fungal diseases like septoria at bay until I have harvested my tomatoes. I also use non-organic fertilizers in my own garden because they are effective and easy to use. The plants I sell are grown using organic methods, but once they hit my own garden I do what is best practice for me to have healthy and productive plants. My advice is to stay away from as many chemicals as you can and to use them judiciously and strictly according to the directions given with each product. If you stay completely away from any non-organic methods expect to have lower harvests and possible crop failure at times; this is why farmer’s have to charge a premium price for organic produce.