Watering Garden Plants

Regular watering is at intervals is better for plants than daily watering.

Ozarks Gardening
Jim Long Copyright 2012

How You Water Your Plants, Matters

We’re all watering our gardens, coaxing them to produce, worrying when the tomatoes and beans wilt in mid-afternoon. Did you know that the watering method you use, can make the difference in success or failure?

One of our friends who visited our Garden Open House this past weekend mentioned that he’d been measuring the amount of water a tomato plant in a 5 gallon bucket uses in a day’s time. He’s determined that a tomato plant with tomatoes on it, uses nearly a gallon of water a day, through growth of the plant and respiration through the leaves. That means tomatoes in the ground require regular watering, too.

But there are ways of watering that help plants - regardless of what plant we’re talking about, be it tomato, pepper or hydrangea - and there are watering methods that can do damage. For example, using one of those hose nozzles that work great for washing your car, to water plants, is a waste. Spray nozzles, aimed at the leaves of a plant, do little for the roots of the plant. I’ve seen gardeners who like to go out every evening with the hose and spray nozzle and “wash down” the plants. While it may make the gardener happy, it does little for the health of plants, and can actually do damage.

Plants (in the ground, rather than potted plants) do best when watered every 4-6 days and allowed to dry out in between. That forces the plant to send roots deeper, which helps protect the plant. When watering is done, there needs to be enough water at the base of the plant that the soil is wet for 6-8 inches deep. Heavy mulch helps hold the moisture in place, as well.

Tomatoes, peppers, roses, dogwoods, herbs such as bee-balm (Monarda sp.) can all develop any of several fungal diseases when spray-watered late in the day. Wilting diseases on tomatoes is made worse when the leaves are left wet before nightfall. Watering the foliage of roses helps insure you will have black spot on the leaves. Powdery mildew on many plants often starts with wet leaves in the evening.

How best to water? I recommend watering plants late in the day, using a water wand (Dramm Watering Wand - those colorful, long-handled watering tools with the shut-off handle, about $17- $20 at stores). Aim the water only at the base of the plant for about 2 minutes, move to the next plant for 2 minutes, then back to the first. You want the soil wet down to at least 6 inches. If in doubt, dig down and see how effective your watering is. Do this about every 4 or 6 days. If you prefer to water your garden with a lawn sprinkler, do it early in the day so the leaves have a chance to dry and don’t water every day.

Happy gardening!