For most vegetable growers, tomatoes are the star of the summer harvest, and late May to early June is the perfect time to plant these warm-weather favorites.
Whether you grow Sungold Cherry Tomatoes, Big Beefsteak Tomatoes, or heirloom varieties, understanding the needs of these red, yellow, and purple beauties will help you ensure a bumper crop of your favorite tomatoes this summer.
Here are some tips to help you grow the best tomatoes this summer.
Proper planting
If you haven't planted your tomato plants yet, choose a spot in the garden that gets at least six to eight hours of direct sunlight each day. Try to plant tomatoes in a garden section that didn't grow plants from the same family as tomatoes the previous season.
This crop rotation practice helps break the cycle of pathogens in the soil. Vegetables in the same family as tomatoes (Solanaceae, or Nightshade) include eggplant, bell peppers, potatoes, tomatillos, and nightshades.
Tomatoes are unique in that they can root on any part of the stem that touches the ground. Planting deeper will encourage stronger roots, so consider removing the bottom leaves and replanting 5 to 6 inches deep. Plant tomatoes a minimum of 24 inches apart in a row.
It is important to keep the soil moist
Ripe tomatoes have a moisture content of about 95%, meaning tomato plants need at least an inch and a half of water each week, either from rain or supplemental irrigation.
Tomatoes have deep root systems, so frequent shallow watering, keeping the top 1-2 inches of soil moist, is not enough to provide the moisture tomatoes need.
Deep watering once a week, moistening the soil to a depth of 12 to 14 inches, will produce more numerous and larger fruit than frequent shallow watering.
Inconsistent soil moisture can also lead to physiological disorders such as blossom rot and fruit cracking. Blossom rot is the dark sunken sore that appears on the bottom of the tomato plant. It is a symptom of calcium deficiency in the developing fruit and occurs when the soil is not kept constantly moist and the plant's roots cannot absorb the calcium in the soil.
Rapid fluctuations in soil moisture can also cause cracks at the stem ends of fruit. Be sure to water the soil but not the leaves to keep them dry, which will reduce the chances of spreading the fungal spores that cause leaf blight.
A 2- to 3-inch layer of organic mulch also helps retain moisture in the soil and can make a big difference in soil moisture.
Pruning for Productivity
Removing suckers, which are side branches that appear in the leaf axils between the stem and the leaf, will result in a more open plant that will produce fewer but larger tomatoes because the suckers compete directly with the main stem for moisture, nutrients and sunlight.
In addition to removing suckers, removing the lowest 8 to 10 inches of leaves on tomato plants will conserve energy for flowering and fruiting and reduce the chances of fungal spores being spread onto the plant's leaves.
Leaves can be removed with scissors or pruning shears, but be sure to sterilize your tools with bleach if you see signs of fungal disease, such as yellow or brown discoloration of the lower leaves of the plant.
Eat a lot of food
Tomatoes absorb a lot of nutrients from the soil and need fertilization to produce a good harvest. As soon as you transplant your tomatoes, give them a fertilizer high in phosphorus to help develop their root system and produce lots of flowers and fruit.
After the first flower clusters set, an additional side application of nitrogen fertilizer will aid fruit development. Side application means applying nitrogen fertilizer 2 to 4 inches to the side of the rows of tomato plants. This fertilizer should be applied to the soil surface and worked in with water, not worked into the soil with a rake or cultivator.
Be careful not to apply too much nitrogen during the growing season: too much nitrogen will result in lush, leafy tomato plants, but few flowers or fruit.
Tomato plants are large and need support. Cages, posts and trellises are all methods used to provide firm support. Determinate-growing tomatoes require supports 2 or 3 feet high, while indeterminate-growing varieties require supports about 5 feet high.
You can purchase ready-made cages or make your own from concrete reinforcing wire. The opening should be 6 inches square for easy harvesting. Set the cage up at the time of planting. Caged tomatoes will be smaller than those supported by stakes and will harvest slower.
If you use stakes, insert them 3 to 4 inches from the stem when planting. The stakes should be sturdy and at least 1.5 inches in diameter, 6 feet tall, and driven 12 inches into the ground. Staken tomatoes can be planted a little closer together than caged ones, about 18 to 24 inches apart.
As your tomatoes grow, tie them securely to the stakes and gently tie them to the plants, spaced 8 to 12 inches apart. Plants hung on stakes should be pruned as they grow.
Pest Scouting
To maintain plant health and maximize production, carefully inspect your tomato plants for signs of insects and fungal diseases. Early in the season, keep an eye out for stink bugs, aphids, flea beetles, Colorado beetles, and spider mites.
In August, start looking for the large tomato hornworm, which quickly devours tomato leaves. If you see signs of fungal disease, such as the lower leaves of your plants turning yellow or brown or dying, you should remove and discard the affected leaves.
Do not add infested leaves to your compost pile.
For more information on growing tomatoes in your home garden, visit go.osu.edu/growingtomatoes
Mike Hogan is an extension educator and associate professor of agriculture and natural resources at Ohio State University Extension.
