You’ve planted your tomatoes and the tiny yellow flowers are starting to show. Now what? Taking a little care during the hot and humid days ahead will guarantee a stellar tomato harvest come August. Here are six things to do:
Trim up the foliage
Start your midsummer tomato care routine by trimming up the foliage at the bottom of the plant. Leave about 6 inches of bare stem between the ground and foliage to reduce or prevent common tomato diseases, which are often caused by soil-borne pathogens splashing up on the plant when you water. You could also add a layer of organic mulch between the plant and the soil to hold soil moisture in and reduce splash.
Water low and regularly
When watering, direct the flow of water toward the soil rather than the foliage. How much water? Tomatoes need a minimum of one inch per week from either rain or the hose. An inch of water is roughly .6 gallons (2.25 liters) per square foot, so your average sized tomato plant needs 1 to 2 gallons per week of water. If you have a lot of tomatoes, you may want to add a drip irrigation system, which waters the plants on a schedule and ensures they are getting the proper amount. One last point about watering tomatoes: Keep it regular. Flooding the plant with water one day then letting it go dry for several days may lead to cracking fruit and other problems. My approach is if it doesn’t rain, water every other day for tomatoes in the ground or in raised beds, every day for those in containers.
Fertilize, if needed
If your garden has soil rich in organic matter, you may not need to fertilize your tomatoes in midsummer. Tomatoes are not heavy feeders and too much nitrogen will lead to more foliage than fruit. But, if you grow tomatoes in containers, as I do, consider adding a low-nitrogen, organic fertilizer in midsummer to help them set fruit and stay healthy. My preferred option is fish emulsion, mixed into water at the rate recommended on the bottle. Give about four cups of the mixture per plant in early July and again in early August. You can also purchase a tomato-specific fertilizer to spread around the base of the plant and work into the soil.
To prune or not to prune is a question that tomato growers have been debating for centuries. You should not prune determinate or bush tomatoes. These tomatoes grow to a certain height and set fruit all at once, then stop. Many paste tomatoes fall into this category. Indeterminate or vining tomatoes keep growing and setting fruit until frost sets in. For those, I remove the suckers that develop between fruiting branches. If a tomato is getting too bushy, I also remove lower branches that have no fruit. You want air to be able to flow through the plant while keeping enough foliage to shade fruits. Exposure to intense sun leads to sun scald on fruits, which is basically a tomato sun blister.
Most gardeners add a tomato cage or stake when they plant their tomatoes. As part of your midsummer tomato care routine, check to see if you need to reinforce your staking. I often add a stake inside the tomato cage to prevent the tomato plant from tipping its cage as it gets larger. Additional stakes, string or other reinforcements will keep your plants upright and healthy.
Monitor for disease
In hot, humid weather, tomatoes can face a variety of fungal diseases, such as early or late blight or Septoria leaf spot. Monitor regularly for spots on leaves, yellowing or wilting. Most foliage-centered diseases will not eliminate your harvest—the plant just looks bad. Diseases on fruits are more serious, but may not affect the entire plant. Allowing for air flow between plants and rotating where you plant tomatoes from season to season are the best things you can do to prevent disease.
With a little care midsummer, you’ll be harvesting plenty of tomato goodness later this season.