By Sally Cunningham
Summer begins in June, just as springtime rainfall usually decreases and plants are growing vigorously. Plants all need water—done correctly. Poor watering is a major cause for plant failure or death, whether it’s your tomato, perennials, shrub, tree, or lawn.
Learn how much to water and how often, for each part of your home garden, landscape, and lawn.
Big roots, small roots
The entire purpose of watering is to supply moisture to a plant’s roots. Two reasons: First, water transports nutrients to produce plant growth. Second, if roots dry out (desiccate) seriously, there is a point of no return. Little root hairs shrivel and can’t take up water. Buds, blossoms, fruits, shoots, or stems collapse, beyond the recovery point, if water doesn’t flow on time.
So the question is—where are the plant roots you are trying to reach with water? That answer governs your watering practices for your new lawn, old lawn, hanging flower basket, perennials, tomatoes, squash, or hydrangea. Whatever watering you do, you must get that water to the plant roots.
For a new lawn, seeded or sodded, that means frequent watering so the tiny roots never dry out and they can grow into the soil. (This does not mean keeping the lawn soggy; good drainage is essential.) For a tree planted a year or two ago, the water must penetrate beyond the depth and width of the root ball. As you get to know your plants, do some testing: After you think you have watered a perennial or shrub, dig next to it to see how far the soil has been dampened.
Waving the hose around to splash water on the plants is NOT good watering. Tickling the top of the soil does not reach roots.
Five Watering Rules
Since your landscaper or garden coach can’t look over your shoulder all summer, these principles or rules will empower you to handle this critical component of plant care:
1 – Water plants before they show stress (typically wilting or drooping).
This is true for houseplants, container plants, or woody plants. Certain plants, such as hydrangeas, are the first to “complain”, in the form of wilting. These stress indicators weaken the plant, slow growth, and increase susceptibility for pest or disease attacks.
2 – Water deeply, not daily.
(The exceptions: New lawns or hanging baskets/ small pots may need daily watering to survive, especially during hot or windy periods.) Once established, plants need encouragement to grow deep roots, which means make them work for it. If the plant gets water daily in the top inches of soil, why would it bother to grow its roots downward and outward? (And once the watering stops, the plant can’t help itself.)
3 – Water at the base of plants and over root systems.
This depends upon your set-up and supplies, but the least effective watering is through overhead watering systems and sprinklers: They waste the most water and lose the most water through evaporation. A sprinkler may help a lawn but totally fail to serve the nearby landscape planting. Home gardeners do best by using a water wand, aimed at the base of the plants. In-ground irrigation systems—best done by professionals—can help large landscape installations to survive.
4 – Time the watering wisely.
The best time of day to water is in the morning (if you can) because the plants can use the water efficiently, and excess moisture dries out. IF you see wilting or stress though, water even in the heat of the day. Evening is not as good because slugs or fungal diseases thrive when the plants stay damp at night. But if you can only get to the hose after supper, then water if the plants need it. (Just avoid wetting the leaves.)
5 –Apply Xeriscape principles.
The term refers to dry-season watering that focuses on water conservation. Xeriscaping came to popular awareness during the last decades when western states have routinely suffered droughts. East-coast, green landscapes do not work well in drought-ridden locations. Everywhere, including in the Northeast U.S., it is smart to design landscapes and gardens with water availability in mind.
Group plants by watering needs. Wet portions of the yard, and places easily reached by the hose, are the places for willows, Astilbes, Rodgersias, and other water guzzlers. Plant heat-tolerant and drought-tolerant plants together so that you rarely need to water once they are established. (Even the most drought-tolerant plant needs water when it is first planted. In the case of trees, that may mean during the first few years.)
How Much Water?
Learn to measure how much water you or natural rainfall has provided. A commonly heard rule-of-thumb says: Most plants need an inch of water per week. That may work for a typical vegetable or perennial garden. But the newly planted landscape plants may need fifteen gallons per week—apiece. One way to measure is by placing cat food or tuna cans around the area to show how much water has fallen.
Lawns in Summer
Learn from your professionals at Lakeside Sod about lawn care through the whole season. There are so many variables that affect best turfgrass watering practices: the kind of soil, sun and wind exposure, the type of turfgrass, how high and often you mow, weed competition, and overall turfgrass health. As we are increasingly aware of environmental and cost reasons to conserve water, consider the following principles to minimize wasting water on lawns:
Healthy lawns can go dormant, and turn brown, in the heat of summer.This does not mean the lawn has died. Cornell University studies have clearly established that a well-grown lawn, with the right kind of seed, with decent soil and good root systems, can stay dormant for six weeks without watering. The grasses will green up and grow again when September rains begin. This may be a healthier practice than teasing the thirsty lawn with daily sprinkling all summer; that practice stresses the plants as they try to grow. A summer nap won’t hurt.
Healthy lawns require organically rich soil. Provide great soil, such as Big Yellow Bag garden soil, or a compost-rich topsoil, when you establish a lawn. And work with turfgrass experts to improve compacted or nutrient-deficient soil in your established lawn. Top-dressing with compost, and de-thatching, are techniques to consider.