By Frank Quinnette, Winterthur Turf Horticulturist
Whether you believe in global warming or cyclic temperature fluctuations, all I know is that it’s been hot and it has finally rained!
After days of the temperature and humidity readings looking like scores from blowout basketball games (104/48 %, 105/52 %, etc) the rain has come to rejuvenate the grass.
The grass going dormant and brown in hot dry conditions is not unusual. The truth is, it is normal for cool season turf grasses to shut down when it’s hot and dry to prevent fatal plant desiccation. The rain today will help wake the grass from its sudden slumber. Watering helps tremendously to cool things down for turf growth to continue in harsh conditions, but it must be done properly throughout the year. The same with mowing. And using drought tolerant turf grass varieties will also help to reduce the effects heat stress from shutting down a lawn.
I’ve come around to the fact that we aren’t set up to water all the turf I want watered here at Winterthur. That’s cool. I’m all about priority. So I try to use good cultural practices all year. Of course there are those years… (2010). Who knew that after 50in. and change worth of snow we would be looking at dry ground this summer? Humidity so low and temperatures so high only scorpions, Gila monsters, and southern Californians could survive.
Watering properly and timely is the key to good turf growth year round.
Water when the grass starts looking “kinda bluish” to quote a friend in the business. You’ve seen it like that. Mostly after it has been cut. It gets that blue-green color to it. If you walk out on it when it’s like that you’ll notice that you leave foot prints that may not go away as quickly as normal. At that point you need about 2 inches of water on it. To measure how much water your sprinklers are putting down, mark the inside if a can or plastic cup with 1 inch increments and place it at the end of the sprinklers reach. Come back after 30 minutes, check the measurement and double it. That will tell you how many inches per hour of water you are putting down on the turf. Make sure you get complete coverage from your sprinklers or you will see the difference later, as shown in the photograph below.
Mowing should be done at the highest setting on push mowers and no lower then 3 inches on riders. The higher the better. A change of half an inch higher can make the difference between a green lawn and toast. You need a sharp blade. Clean, even cuts heal faster and prevent water from escaping from the grass plants. Mow when it is coolest during the day. Evening is best for me at home mainly because my neighbors formed a lynch mob the last time I tried to cut my grass before 9am. Here at Winterthur, I mow when I can see the grass and go until things get a bit too warm. Almost never past 11am when temps are expected to be above 90 degrees. That gives the grass time to recover and heal before the hottest part of the day. If you do mow in the morning, water right after you are done to reduce stress.
Drought tolerant grasses such as tall fescue are thick bladed, clump type grasses that take heat like a champ. Properly seeded in the spring or fall these grasses are great for areas where watering times are few and far between. We use mostly tall fescue mixes. Check with your local garden center to help with best seed choice for your lawn.
If your grass has gone dormant because you’ve done none of the above, then good for you! That’s where we’re at here at Winterthur. You don’t have to mow. You don’t have to water. I wouldn’t get too close to it with an open flame but you can claim it on your taxes as energy efficient savings (joke…I’m not an accountant or a tax cheat). But it is good for the environment in a way. The use of that method at Winterthur allows me some time to become reacquainted with my team mates and some muscles I haven’t used in a while. I also get to write this.
