FIMBY: Maintain moisture for garden success

This is another installment in our Food in My Back Yard series, dedicated to edible gardening.

Our gardens are about to be tested. According to the National Weather Service, Sacramento will see high temperatures in the 90s by Friday (May 9); the “normal” high for this week is only 77 degrees. Accompanying that sudden heat is strong wind that can suck the moisture right out of leaves and soil.

That rapid warm-up can be disastrous to tender young transplants. They can go from lush and green to parched and brown over one hot weekend.

Plants need moisture in the soil in order to access nutrients. If there’s no available water in the surrounding soil, the roots will pull water from the rest of the plant. The foliage will turn crisp and look burned.

Once they hit that stage, there's no bringing back those leaves (clip them off or let them fall), but the plant itself can be saved – if it gets water before the roots dry out, too.

But why put your plants through so much stress? Don’t let them totally dry out in the first place.

This is particularly vital with fast-growing vegetables such as tomatoes and squash. Maintaining even and consistent soil moisture helps a plant grow at a consistent rate. It also helps prevent blossom end rot, a common problem in tomatoes, peppers and eggplant.

Think of it as the Goldilocks Zone; keep soil not soggy, not bone dry, but just right.

What’s just right? Grab a fistful and squeeze; it should clump together in your hand. If the dirt just crumbles through your fingers, that soil needs water.

Or try sticking a screw driver into the ground; if it can’t go down 6 inches, that soil is too dry and hard.

For a more accurate measurement, use a moisture meter. Simple and cheap, these meters work like an instant-read thermometer – stick it in the ground and see the result.

Once you find the Goldilocks Zone, how do you maintain it? With mulch.

A blanket of organic material – straw, dried leaves, wood chips, ground bark, etc. – helps keep soil moist. Water doesn’t evaporate as quickly (which saves water, too). As they break down, these organic mulches gradually add nutrients to soil, too.

Organic mulch also helps regulate soil temperature, keeping it several degrees cooler during hot summer days and making roots comfortable.

Mulch had another benefit: It smothers weeds. That cuts down on work and saves gardening time.

Wood chips and other mulches may pull some nutrients out of the soil as they start to break down. To balance out that process, put down a thin layer (about an inch) of aged compost and then top with 2 to 3 inches of mulch. That double layer not only maintains moisture and soil temperature, but adds extra nutrients, too – making the mulch even more effective.

When applying mulch, don’t let it mound around stems, crowns or trunks; that can hold in too much moisture and lead to crown rot or plant disease. (This is especially true for trees and shrubs.) Instead, make a little mulch-free circle – about 4 to 6 inches – around the plant.

Need mulch? You’re in luck! Mulch Mayhem is Saturday, May 17.

Coordinated by the Regional Water Authority and local water providers, this one-day event offers free mulch to local residents. Attendees can pick up one cubic yard of mulch – mostly fresh wood chips – per household at participating locations throughout Sacramento and Placer counties. Supplies are limited; plan on arriving early.