Practical Tips for Thriving Plants
All tomato varieties are really very similar in their physiology, and as such, there are no "drought-resistant" varieties, just some varieties that yield better results with low water application than others. This is why we have no category entitled “drought-tolerant-tomatoes.”
That being said, here are a few general rules that may help you select the right tomatoes for your garden.
Start with the Right Type
Cherry tomatoes are more tolerant of low water than their bigger counterparts. The closer to the wild type a variety is, the sturdier it will be in general. A cherry or saladette/slicer will be more tolerant of water stress than a big beefsteak or heart. Many cherry tomatoes, however, are well known for their tendency to split if watered irregularly; Sungold is an example of this problem. In this respect, cherries aren't as good in a drought as a thicker-skinned slicer.
Understand Paste Tomatoes
Dry-fruited tomatoes are more susceptible to blossom-end rot (BER) if they dry out too much, as they're closer to their moisture limit to start with. Paste tomatoes like San Marzano or Roma can get by with reduced water, but they have to start with it, not have it imposed mid-season. Even then, if they get too dry in very late summer, BER will return, as they wilt in the middle of the day.
Watch for Pests in Dry Conditions
Drought-stressed tomatoes are more of a target for pests, like thrips and mites. In 'Our Garden', we’ve noticed problems with the russet mite; plants short on water will be hit even harder. Mites like dry, hot, dusty conditions. Borderline dry farming can produce just such conditions that foster mites, even when the plants are otherwise doing well. You should mulch around your tomatoes to keep the dust down, which helps prevent mites and keeps moisture in the soil.
Know Your Soil
Soil type makes a big difference in how often you need to water:
- Clay soil holds moisture well and is ideal for low-water gardening.
- Sandy soil drains quickly and dries out fast.
- Containers dry out even faster than sandy soil and require more frequent watering.
If you’re planting in the ground, understanding your soil is one of the most important first steps.
Adjust Your Irrigation
Changing your irrigation will also help promote low water use. You can sink short lengths of PVC pipe in the ground and put a drip output in these underground PVC pipes. This means you leave the top 3" of soil as a dry crust to conserve water. This works particularly well if the soil is dense.
Prepare the Planting Area
Digging a 3'-wide, 8"-deep hole for each plant and lining the hole with organic material also helps. When you get past 6" deep all plants are looking for is water, not nutrients. Planting earlier may also make a difference.
Keep the Bigger Picture in Mind
Home-grown produce, especially when watered efficiently, often uses far less water than commercially grown crops. Since we all rely on food production, it makes sense to focus major water-saving efforts on areas like lawns or high-water ornamental plants rather than cutting back heavily on food gardening.
With thoughtful choices and a few adjustments, it’s entirely possible to grow healthy, productive tomatoes using less water. We encourage you to keep growing your own food and enjoy the process along the way.
UC Master Gardener Program of Contra Costa County
2380 Bisso Lane, Concord, CA 94520
Website: https://ucanr.edu/site/uc-master-gardener-program-contra-costa-county