GIMME SHELTER- Early heat: Treat it like summer
Q: How can I take care of my lawn in this heat wave we've been having? What do I need to do to keep it thriving?
A: July and August are usually the tough times for lawns in Central Virginia, but with the heat wave we've been having, June appears to be just as tough. In fact, if this continues, the summer months could be unusually hard on your lawn. Unfortunately, grasses planted around here are either Fescue or Bluegrass varieties. These are cool season grasses that tend to do better in colder climates.
So why don't we just plant warm season grasses? Some people do; those species are typically Zoysia or Bermuda Grass. They thrive in hot weather but are not frequently used here as they don't "green up" until late May and have a very short growing season, typically only through October– if you're lucky.
That being said, the typical (cool season grass) lawn is having a tough time right now. Unfortunately, there's not a whole lot you can do. However, what not to do is crucial: do not apply fertilizer now to a lawn without irrigation. Water or increase irrigation if your lawn is small enough. With water, do not exceed the rainfall equivalent of one inch per week, and water in the early morning to avoid evaporative loss of expensive water.
If you have an irrigation system, set it to come on around 4am and be off by daybreak. Avoid watering in the evening or around midnight, as the increased duration of foliar wetness can lead to fungus. If you water, be aware your water bill will take a huge hit– it's easy to triple your water consumption.
If you insist on significant watering of your lawn, it's best to have an irrigation system hooked up to an exclusion meter, which measures only outdoor water consumption. Thus you're not billed for sewer, and you can cut your water bill back down.
Another tip: check your mower. Are the blades sharp, or is there a lot of grass buildup under the deck? Proper mowing, in my opinion, is the most important aspect of turf management. A dull blade does not cut grass; it tears the leaf. The grass plant is then more disease-prone. Mow when necessary. If the grass is brown and crispy, avoid needless mowing (and other traffic such as ballplay). If the grass is growing quickly, mow frequently.
Use the "rule of thirds": do not cut off more than 1/3 of the grass leaf per grass cutting. Also, change your mowing pattern by mowing perpendicular to or against last week's pattern.
Generally, you should cut your grass taller in the summer months (4 to 4.5 inches) to promote root growth and heat tolerance. Cutting high also discourages weeds without the use of herbicides.