Summer Stresses on Turf Grass
What is Stress?
To determine whether stress is a problem, it is important that you understand the definition of stress, as well as know the optimum conditions, for the plants growth. The ideal temperature for Kentucky Blue grass growth is 50-65 degrees for the roots and 60-76 degrees for the shoots. This grass also requires good soil conditions, moisture and sunlight to maintain growth.
The actual temperature the plant experiences can be considerably cooler or warmer than the current air temperature. Where moisture is limiting, the temperature of the plant will usually be higher than the air temperature because the plant is not able to transpire water, (in humans, we call this perspiring).
Man’s activities also influence the plant’s ability to withstand environmental stress. Traffic on Turf grass causes the soil to become compacted, which means the soil particles are compressed into vacant pore space once used to hold water. This results in less pore space for root growth, less air and water storage and a soil that is more susceptible to temperatures extremes. The air in the soil pores helps insulate the soil from rapid changes in temperature. The best way to combat the process of compaction is to core aerate.
Fertilization programs also influence a plants ability to withstand stress. Nitrogen fertilization during stress periods can cause excessive shoot growth that is detrimental to the root system. University research however indicates that high levels of Potassium (K+) fertilizer will help a plant withstand drought stress when applied. Pesticide applications can sometimes influence the grasses stress tolerance. Improper applications either high rates of chemicals or inappropriate pesticides will result in turf injury.
Finally, the presence of insects and disease can reduce the plants ability to withstand environmental stress. The interaction of the environment and these cultural programs determines overall turf health and its ability to withstand environmental stress. Successful Turf grass managers strive to understand this interaction and adjust their management practices to produce the best possible result.
The primary turf grasses grown in lawns in NE are cool season grasses. The most common species of cool season grasses used in residential lawns include Kentucky bluegrass, perennial ryegrass, fine fescue and tall fescue. Cool season grasses perform best when daytime temperatures are in the range of 60 to 75°F along with adequate soil moisture. These lawns possess the best color and quality attributes during the spring and fall seasons. Being cool season grasses, good to excellent winter hardiness allows established lawns to survive even the harshest NE winters.
The most stressful time of the year for cool season grass home lawns in NE is typically encountered during the summer (i.e., June through August) period. This period is often characterized by hot, sunny days with daytime temperatures routinely in the low to mid 80′s. In addition to high temperatures, moderate to severe moisture stress is often imposed on the turf grasses during this summer period. The combination of high temperatures and dry soils will often lead to significant declines in quality and losses in turf grass unless proper management practices are implemented.
The interrelationship between water stress and heat stress is exemplified among the cool-season turf grass species, particularly, annual bluegrass. One of the first occurrences during heat stress is “die” back of the root system with no new root initiation and replacement. Heat stress is just that, it can come from excessive sun, compacted soil, or most commonly large rocks, or boulders, just under the soil collecting the sun’s heat. Lack of top soil or loam is the root cause of heat stress.
Physiologically, one of the first changes as an internal water stress develops is closure of the leaf stomates. During intense heat, the internal death is heat stress. Leaf temperature can rise to lethal levels above 104 degrees in a matter of 30 to 60 minutes after stomatal closure. In this situation, the final cause of plant death is heat stress, but it was induced by internal water deficits.
Stress can be caused by any number of variables. Please allow a professional to diagnose all turf problems you may have. More often than not there is an easy solution. Ignorance is not bliss when it comes to your landscape!
Identifying and Preventing Sod Webworm Damage
Many homeowners are intimidated by the prospect of pruning. Knowing that improper pruning can lead to a sick or otherwise compromised tree or shrub can be too much for some people, especially after they have invested so much in their landscape.
No matter how scary the idea of pruning is, it should be a practice you get into with comfort and regularity because a well-pruned plant is a healthy plant. Pruning improves the flow of moisture and nutrients through the plant, as well as allows thriving areas to receive most of the nutrition while dead or dying areas are removed from the plant, according to lawn care agents.
Pruning is one of the best practices you can perform on the plants in your garden and landscape. Lawn care experts say becoming proficient at pruning plants just takes experience and the right tools. Here are four basic tools that will take care of pretty much all your garden pruning tasks. You should keep these tips in mind when selecting your hand pruners, loppers, shears and saws:
- Don’t be cheap when it comes to investing in pruning tools. Good quality tools stay sharp longer, cut easier and will last longer, paying for themselves in the long run.
- Keep your tools sharpened to make cutting easier and to produce clean cuts that heal faster. A sharper pruning tool also puts less stress on your hand, according to lawn care professionals.
- Keep your pruning tools clean and clean the blades in between trees or shrubs. One pruning cut on a diseased branch can spread disease throughout your garden. Wipe the blade clean with rubbing alcohol. Don’t ever put your pruning shears away without cleaning them first.