While tomatoes are the most commonly grown vegetable, they're also one of the most problematic. A wide range of pests and diseases can attack tomatoes, ruining your plants before you get to enjoy a full harvest. Here's help.
Choose Good Growing Conditions
Tomatoes, like most vegetables, grow best in a spot with full sun and well-drained soil. They'll be more prone to disease if you plant them in heavy clay soil or shade. Also, it's helpful to plant tomatoes in a different part of the garden each year as diseases can build up in the soil.
Stop Disease from Building Up in the Soil
If you have poor soil or don't have the option of planting your tomatoes in a different spot each year, try growing them in containers. Most tomatoes do really well in large pots filled with a potting mix designed for container-grown plants. Just be sure you have a big-enough pot -- at least 12 inches in diameter -- many tomato varieties can grow 6 feet tall by the end of the season!
Select Varieties for Your Situation
There are literally hundreds of tomato varieties on the market. Different types are best adapted to different areas. For example, the University of Florida has released varieties such as 'Solar Set' that thrive in hot, humid conditions. Other areas, such as 'Northern Delight', have been bred to produce fruit quickly and are best for short-season areas. Check with local experts, such as your county extension agent, for recommendations.
Another key to preventing disease problems is to select disease-resistant varieties. These will often have a letter, or series of letters (such as VFFN), on the plant tag or in the seed-catalog description. These letters stand for different disease strains.
Give Them Good Care
Stressful growing conditions weaken plants and make them targets for disease. So make sure your tomato plants are well watered during dry spells and well fed during the season.
To help cut down on competition from weeds and to help the soil hold moisture better, spread a couple of inches of mulch over the soil surface. Mulch can also create a protective barrier that helps stop soil-borne diseases from splashing up onto and infecting plant leaves.
Wet foliage can encourage fungal diseases, so it's especially helpful to water your tomatoes with a soaker hose or drip irrigation instead of with a sprinkler or spray nozzle on your garden hose. If you have to water from the top of the plant, do so before noon so the leaves have plenty of time to dry before temperatures cool down at night.