A dry summer is what your tomatoes and peppers love. Here's how to handle it best.
After a dry-ish winter and a very dry spring, the prospect of a dry summer seems daunting to many gardeners. How can we keep everything properly watered through the heat?
That’s a good question, and anything that’s been routinely over-watered (looking at you, lawn) is definitely going to show some stress. To promote deeper, more resilient roots, wean irrigated areas slowly, accustoming them to an inch of water total each week.
Lettuces and other greens usually bolt early in warm, dry years. Unless you have a bed that’s shaded in the afternoon, replanting may not be very successful until fall. If trees start dropping fruit before they ripen, give them a slow soak once a week, focusing on the dripline where the active feeder roots live. Mulching with shredded wood chips (not bark) will help lock in moisture once the soil is wet for several inches down.
Fortunately, tomatoes thrive in hot, dry summers-as long as it doesn’t get too hot. On over-80-degree days, tomatoes may drop blossoms rather than set fruit, so a shade cloth screen can help them keep their cool. Once fruit set begins, Italian tomatoes and peppers are traditionally grown on the dry side. That doesn’t mean no water; if the foliage flags a bit by day but perks back up again overnight, they’re getting enough.
The deepest, richest flavor develops when they’re grown that way, and fed with lower-number fertilizers like Dr. Earth’s. Excess water and fertilizer will dilute the tart-sweet flavor of tomatoes and the bold bite of peppers. High-number feeds mostly end up in Puget Sound anyway as plants can’t access that much food all at once. The best fertilizers include minerals and plant probiotics, which promote more complex flavor profiles and improve soil quality as well.
Excess water also favors foliar blights and root rot, especially when foliage gets wet. One effective way to discourage blight and pamper your plants is to mulch them with used coffee grounds (do remove the filters first). Coffee grounds contain about 2 percent nitrogen, 0.06 percent phosphorus, and 0.6 percent potassium by volume. Coffee micronutrients include calcium, magnesium, boron, copper, iron, and zinc, plus coffee grounds dehydrate slugs!
If tomato stems break before the fruit ripens fully, that may also be due to water-soluble fertilizers, especially with container-grown plants, since daily pot watering dilutes and rinses away soluble fertilizers quickly. Plants in the ground have access to soil nutrients not available in potting mixtures, so feed potted plants every two weeks if using water soluble fertilizers. Liquid seaweed extracts will help strengthen weak stems by supporting steady plant growth even when cool nights follow warm days. Kelp extract combines micronutrients and trace elements with natural plant hormones and growth stimulants that promote root growth, improve stem and foliage density, and increase chlorophyll production.
Strong wire cages offer plenty of support for determinate tomatoes. Train indeterminate types on supports to keep fruit off the ground, using soft ties that won't cut stems. Keep tomato foliage dry and prune yellowed leaves immediately. Prune indeterminate tomatoes as needed to keep plants compact and productive. Thin tomato foliage once fruit sets begins to improve air circulation and allow more sun on the fruit. Leave enough foliage to feed the plant (photosynthesis, remember?) and thin slowly over a period of weeks, rather than all at once. Sudden hard pruning can cause sun scald, burning the shoulders of newly revealed tomatoes when foliage is removed. Sunburned tomatoes develop yellow or white patches which look funky but don’t impair the flavor or texture at all.
Onward, right?
Contact Ann Lovejoy at 413 Madrona Way NE, Bainbridge Island, WA 98110 or visit Ann’s blog at http://www.loghouseplants.com/blogs/greengardening/ and leave a question/comment.
This article originally appeared on Kitsap Sun: How to water your garden during a dry summer in Washington
