Understand water requirements for a healthy lawn

By Wayne Wells, David Nagel, Lelia Kelly

Extension Horticulture Specialists

Distributed by Lisa Stewart, Webster County Director

 

Water is one of the most unique, mobile and abundant compounds on earth and any living thing cannot survive without it. Our lawns are no exception and as the days become warmer our lawn’s demand for water will be even more critical.

I am often asked how much water does a lawn need each day or week and as a general rule the answer is somewhere between one to three-tenths of an inch per day or one to 1½ inches per week when the turf is actively growing. Of course these amounts vary depending on a host of environmental and physical conditions such as temperature, wind, clouds, traffic, soil type and turf species.

When supplemental irrigation water is needed it should be applied in thorough less frequent applications to moisten the soil to a depth of three to four inches to encourage a stronger deep-rooted turf. A light sprinkle each day encourages shallow rooting and greater evaporation loss.

Understanding the functions of water to a lawn will help determine when your lawn needs water. Water is essential for the uptake and serves as the transport medium for nutrients into the plant. Water serves as the solvent or catalyst for metabolic processes and is required for photosynthesis. A healthy lawn is a tremendous air conditioning system as it transpires water to moderate temperature changes of plant cell protoplasm, maintain cell turgidity and opening of stomata.

Water is also necessary for seed germination and the survival of beneficial bacteria and fungi that help decompose mowed leaf clippings. Therefore, when all of these functions are going on at the same time the lawn will demand and require the highest level of water.

Excess water can often be as detrimental as too little water. Compacted soils with poor internal soil drainage will reduce soil oxygen resulting in lower root mass and depth. With a much smaller, stressed root system the turf plant can’t take in the water and nutrients needed for optimum growth and appearance.

Hollyhocks

Hollyhocks are in full bloom now. The old-timey single bloom varieties are still available and can add that look of country charm to any garden. These plants, although listed in most texts as biennial, behave as perennials coming back year after year from the same rootstock.

Blooms open from the bottom to the top of the bloom stalk ensuring a continuous succession of bloom for weeks. Some gardeners stake the tall bloom stalks to keep them upright during windy, rainy weather. I just let mine flop where they want. If you don’t want volunteer seedlings or you don’t save seed, you may cut the bloom stalk down after flowering is complete.

Annuals

You still have time to set out summer bedding plants. Keep them watered until the roots grow into the surrounding soil. Plants in full sun will benefit from the temporary shade of pine needles sprinkled lightly over the transplants.

Shrubs

Containerized evergreen and deciduous shrubs for accents or foundation plantings can be planted all summer; just keep them watered, and mulch after planting. Be sure to ask about suggested spacing requirements when planting masses of the same plant.

Rootstock Rose

An unfamiliar flower on grafted roses means that the rootstock is blooming instead of the grafted portion. Cut the rootstock branch back to the ground to prevent it from becoming dominant.

Vegetables

Sweet corn growers should be paying close attention to emerging silks. When the ears are fully formed the silks emerge from the husk at a slow but steady rate. Watch the silks for signs of corn ear worm eggs. The newly laid white eggs are about a thirty-second of an inch in diameter and ribbed ( magnifying glass needed).

The eggs turn dark and hatch in about three days. It is much easier to stop the insect at the egg stage or young larvae stage outside the ear than it is to try to kill it after it enters the ear. Insect control measures include wiping the silks with mineral oil that will prevent the worm from ever getting into the ear. Remember to treat the silks, not the whole plant.

Many gardeners wish they had sweet corn old enough to be silking. The cool wet spring delayed most gardeners in the state to the point where the planting was as much as a month late. The late start means many plants are still juvenile at temperatures where they are normally in the reproductive phase.

This may be the year where the first cluster of tomatoes is actually set and we can see the true size potential of some varieties. Keep in mind that high temperatures and wind create higher water requirements.

Rains may have leached fertilizer below the root zone of vegetables. A side dressing of fertilizer should be considered if the plants are not growing well or have paled in color.

Be careful transplanting this time of year. Moving transplants from a protected structure like a green house, hot bed or windowsill directly to the garden may be disastrous. The high light intensity during these long days may sun burn the plants unless they have hardened off by placing them in direct sun for an hour or so and returning them to cover for a few days.