Summer Watering Strategies: It starts in spring!
Practices we use throughout the spring in the landscape will help build up the plant’s defenses against the harsh July and August conditions in Kansas City. Genetically, many plants are tolerant to heat and dry conditions, but there are several important practices we can do now that will help prepare the plants for what lies ahead.
Tips to help plants survive summer conditions
One of the best tips is to not start anything now that you cannot finish later on this summer. By that I mean keeping plants on the lean side with moisture encourages roots to develop and move deeper into the soil. The only exception to this rule is newly planted trees and shrubs.
Turn off the sprinklers
Keep the sprinklers turned off until the real stress of summer’s heat arrives. Plants become accustomed to an ample water supply. It encourages shallow roots. These roots are the first to stress and function less efficiently during the dog days of summer. Deeper roots are cooler and have a better supply of soil moisture found deep below the soil surface. In most Kansas City summers, sprinkler systems should remain turned off until late June. If a dry spell does occur and the general landscape needs a drink, then turn it on for an application. It would be better to just spot water the trees, shrubs or new flower plantings instead of soaking everything with a typical sprinkler application.
The benefits of mulch
Mulch is also our best defense for water reduction and healthy plants during summer. Mulch provides so many benefits, but when it comes to moisture the main advantage is that it shades the soil, reducing evaporation and reflecting the heat of the sun, thereby keeping the soil cooler. The result is a tremendous savings by reducing the frequency of watering. In fact, mulch is so important to conserving water in the landscape that all bare soil areas should be covered.
Apply a 3 inch layer of mulch in flower beds and around shrubs and young trees five to 10 years in age or older. Mulch can be any organic material, from recycled grass clippings, wood chips from local arborists to bagged and bulk materials available through many outlets. The only secret to mulching, besides the depth of the layer, is to keep the material out and away a few inches from the bases of the plants. This helps reduce decay of the live tissue during periods of high rainfall.
Cut back on fertilizers
Reducing the amount of fertilizers will also decrease the plants need for water. Think of it as eating a salty meal — just as you crave water afterwards, the same is true for plants. High fertility increases the need for water. Avoid a fertilizer application from now through the rest of summer on trees and shrubs. Annual flowers, which normally must be watered on a regular schedule, should still be fed.
If you must water do it correctly
When watering, we recommend doing it properly by watering less frequently and more deeply. This method encourages deeper roots and is important in managing our local heavy clay soils. Clay soils hold water and drain slowly. Applying the water quicker than the soil can absorb it results in runoff and a waste of water. Applying water too frequently does not allow the water to move into the soil profile and can result in decreased oxygen levels, drowning the plants.
The best schedule is to water new trees and shrubs about once a week, and do it slowly so that the water is absorbed and wets the entire root profile to a depth of at least 6 to 8 inches. As a guide, a young tree may need as much as 10 to 20 gallons of water each week, which completely soaks the soil from the trunk to an area past the drip line.
These are just a few tips that are easy to do but can provide big dividends for a healthy landscape. Now is the time to start developing a more drought-tolerant landscape by following just a few simple guidelines.