4 Tips for summer stressed lawns
This article applies to cool-season turf, if you're reading this from anywhere in Canada, for instance, Kingston, Ontario, this is for you!
Some background info
Cool-season grasses come in many varieties, and were talking thousands of species, some annual, some perennial and they all generally perform best around 16 degrees Celcius but can certainly thrive in temperatures up to 24 with adequate water. Your lawn is composed of perennial cool-season grass and follows a basic cycle: the most growth occurs in spring, this is where the stored energy is depleted the fastest. Once summer arrives, many lawns will enter dormancy where growth is stunted and the plant just focuses on surviving. Finally, autumn brings growth once again but not quite as much as in spring, nearing winter is when the grass stores energy more than any other time in preparation for spring green-up, completing the cycle.
Summer stress herein refers to a combination of drought stress, heat stress, and even UV damage. These are examples of abiotic stressors that will accompany each other to the detriment of your lawn and many of your plants for that matter. To make matters worse, "biotic stress" including predatory insects, bacteria, and especially funguses will take advantage of the weakened state of the grass and compound the stress creating an even bigger problem.
Tip #1 Don't over-fertilize
In this case, what we mean is overdoing nitrogen (N-the first number on the bag) and we are only referring to synthetic fertilizer. Overdoing N in the spring will deplete your lawn of stored carbohydrates faster and will put too much emphasis on growth neglecting defensive mechanisms and even masking diseases. Further, even slightly overdoing the N in the summer can quickly lead to fertilizer burn that cannot be corrected until fall growth. Conversely, under-doing N in the spring can be a missed opportunity to develop strong turf capable of riding out the summer with some added irrigation. This leads me to the next tip...
Tip #2 Water management
Plants are truly amazing, creating food from sunlight, CO2, and water. Don't forget, plants need water to live and lawns are no exception. When we fertilize we aren't feeding the grass, grass feeds itself, of course, your lawn needs more than just the sugar it produces and that is why we fertilize. Grasses are extremely well adapted to taking up moisture from the soil, they have very fibrous root systems that scavenge moisture from soil you would otherwise consider to be dry. In fact, the grass is so good at obtaining water that it will even slightly reduce your AC bill through evaporative cooling. Watering takes careful consideration based on your geographical area, water pressure, soil structure, grass type, and so on. When watering your lawn, soaking the soil on a schedule is going to be better than frequent watering by hand, the exception is watering dry spots by hand because you can quickly soak a single spot with the average hose.
Tip #3 Build your soil
Building soil should be the main focus of any lawn care program, this becomes clear as summer approaches and sandy soils become arid, unable to hold water and on the other hand you have clay soils that become rock hard, repelling precious water. Luckily, organic material loosens hard clay soils and moistens arid sandy soils for a much more stable soil. The more variety of organic material added, the more diverse your soil becomes, building a more desirable soil over time. A program utilizing organic fertilizer and compost combined with regular mowing and proper use of water is our recommendation. We don't recommend "worm tea" or any designer microbes at this time, these perform well only in controlled settings such as indoor growing. Applying live microbes to your lawn will not help much of anything, there is just too much competition already present in the soil for these products to be effective. Organic fertilizers on the other hand provide ample food source for beneficial microbe populations and will increase diversity more reliably than specialty microbial products.
Tip #4 Proper mowing
Mowing has a great impact on overall turf health and summer cuts can make or break your lawn this year. We highly recommend raising the blade to 4" during the summer, scalping the lawn should always be avoided but this goes double for summer. A sharp mower blade will also help to reduce overall stress each time you cut the grass, and it is wise to mow in the evening, after peak heat.
There aren't any single magic solutions to perfect grass but by following the above tips you can keep green all summer long. During daytime high temperatures above 25 degrees your lawn is experiencing heat stress, one way to cool your lawn down is with mist. Ever been to a misting station at a theme park? The same principle applies to the turf, pull out the garden hose and spray a fine mist on your grass during peak heat to give your lawn a break from the extreme heat. It's not great to soak your lawn during peak heat because of evaporation, you end up losing more water than soaking the grass in the morning or evening. With mist, we want evaporation because it cools the turf, and the finer the droplet size the better. And in case you are worried about so called "leaf scorch", you can rest easy because it is nothing but a myth. Water droplets do not act as tinny magnifying glasses for sunlight to scorch leaves, if they did, Florida sun-showers for example would devastate most of the plant life there but this is just not the case.
Summer is tough on grass but healthy lawns are possible with the right management. The tips we went over didn't go in to extreme detail so we recommend speaking with a local professional to perfect management in your area.
Renewalawn treats the core problems, rather than the symptoms of your lawn, with innovative and organic lawn care solutions that leave your lawn green and healthy. For more information, check out our lawn care services in Kingston.