We’re deep in the heart of tomato-growing season, and as the summer continues, it’s important to follow a few simple steps to keep your tomato plants happy and healthy.
1. Mulch
To maintain even soil moisture levels and to limit weed growth, tomatoes should be mulched early in the season. Use a 2- to 3-inch layer of organic matter, such as untreated grass clippings, straw, finished compost or finely shredded leaves, to mulch the plants, making sure to keep the mulch a few inches away from the stems. Mulch also cuts down on soil-borne diseases, like early blight. The spores of this fungal disease easily splash up onto the foliage during rain fall, but a thick layer of mulch helps protect the plant from exposure.
2. Fertilize
Tomatoes use a lot of nutrients during their growth. Maximize production by working a few inches of compost into the garden each spring. Complete organic granular fertilizers with a slightly higher phosphorous content can help with fruit set. Avoid high-nitrogen fertilizers, as they promote leaf production, sometimes at the expense of fruit. Liquid fertilizers, including fish emulsion and liquid kelp, can be used throughout the summer for an extra boost of macro- and micronutrients.
3. Stake
To keep the developing fruit off the ground and away from slugs and other insects, tomato plants should be staked or trellised. There are 101 different ways to do this, and every gardener has a favorite technique. It doesn’t matter how you stake your ‘maters—what matters is that you do!
One simple technique is to use a 1-by-1-inch hardwood stake and some jute twine to train the plant. Another is to use a wooden or metal tomato “cage” to keep the plants upright. Some folks prefer an A-frame trellis that supports two plants at once, and still others use spiral stakes or twine lines to trellis multiple plants in a row.
4. Prune
Or don’t. Some gardeners swear by removing the side-shoots, aka suckers, from their tomato plants, while others let them grow. Yes, these shoots will eventually produce fruit, but they can grow into an unruly mess, if not supported properly. I’m a religious tomato pruner in my own garden, preferring to regularly pinch off the suckers. I feel it improves air circulation around my plants and helps cut down on fungal diseases. I grow lots of tomatoes in a fairly small space, so pruning my plants lets me fit more varieties into the garden, but I know plenty of gardeners who allow the suckers to grow—they swear they get more fruit and the ripe tomatoes are shielded from sun-scald. The truth is, whether to prune or not prune is the gardeners choice.
5. Regular Disease Checks
A very important practice in the tomato patch is a regular check for foliar diseases. Walk through your garden twice weekly, examining the plants’ foliage for dark spots, discoloration, yellowing or other indications of disease. If you notice marred foliage, snip off the damaged leaf with a clean, sharp pair of pruners and take it in a sealed baggie to your local nursery or extension agent for a proper identification of the disease. Some online sources can also help identify foliar diseases on tomatoes. Suggested treatment depends on the specific disease and a proper diagnosis is key for early control.
6. Water
Tomato plants require at least 1 inch of water per week, whether from the end of your hose or from Mother Nature. Avoid overhead watering, such as from a sprinkler, whenever possible because wet foliage can promote fungal diseases. Drip irrigation or targeted soil-level irrigation is best. Always water in the morning so the foliage has time to dry off before nightfall. If you mulch your plants well early in the season, supplemental irrigation is seldom necessary, except in times of drought.
