Toronto Star column – published June 8, 2013
Now that June is here, summer weather will come calling, with high temperatures followed, no doubt, and a lack of water. Time to sit back and let your lawn take care of itself.
Where did home turf get the reputation for being an environmental bully? I can’t say for sure but I do know this much: if there is an underappreciated element to Canadian horticulture, it is the garden variety lawn. Truth is, you can have a great looking lawn without the supposed ‘work’ or environmental detriment. This is the perfect time of year to employ a few important tactics in your effort to do just that.
Environmental Benefits of Lawns.
First, let’s get the negativity out of the way. According to the North American Lawn Institute an ‘average’ sized suburban lawn produces enough oxygen to support a family of four. A lawn is not some green carpet that the Blue Jays play on (which is fake turf) but a high functioning, living, breathing colony of oxygen-producing plants that are knit together to form a low-growing welcome mat to your home.
A properly maintained lawn is cool to walk on as it transpires moisture through its blades. As it cools the air it also cleans it, through the miracle of photosynthesis.
As rain falls, toxins are filtered out of it through the sophisticated root structure of grass plants. Not only do grass roots slow the flow of water through the soil, preventing flooding, but they also absorb an enormous amount of moisture in the normal course of their work day. That is not to say, however, that a lawn is a water hog. Read on.
You can give your lawn a boost and help it do its job more efficiently by following these few simple steps:
1. Cut your lawn high. 6 to 8 cm will do the job. For generations we cut our lawns much shorter, not realizing that tall grass blades produce deeper roots that are more drought tolerant. Also, the taller the grass blades the fewer the weeds as weed seeds are ‘shaded out’ by the grass before they get a chance to germinate. More on weed control later.
2. Use a mulching mower. The cut grass blades are regurgitated up into the cutting chamber of the mower where they are re-cut before being thrust down into the root zone of the grass plants. As they decompose they add precious nitrogen to the soil: the element that grass plants crave the most.
3. Fertilize three times a year. Sometimes lawn fertilizer is called lawn ‘food’ but this is inaccurate. Fact is, your lawn feeds on soil-born nutrients and takes the nutrients up with the assistance of microbial activity in the soil. It is a little complicated. What you really need to know is that a quality lawn fertilizer provides nutrients to the soil that are used by the grass plants to grow and thrive. The aforementioned nitrogen is the primary ingredient in a spring/early summer application of fertilizer, and is always represented by the first number in the three number analysis on the bag.
4. Slow release nitrogen. The nitrogen that produces the best results in your lawn is most useful to it when it is released over an extended period of time. One of the most sophisticated forms of slow release nitrogen is sulphur-coated urea. It releases nitrogen to the root zone as rain falls, temperatures rise, and microbial activity occurs in the soil. Iron also plays a role, as it helps to produce green chlorophyll, deepening the colour and enhancing the appearance of your lawn.
4a. Alternative! If you prefer to use a non-synthetic fertilizer on your lawn, apply corn gluten. It has less nitrogen in it than most lawn fertilizers but it breaks down relatively slowly and it has some herbicidal properties. It can prevent the germination of crabgrass seeds, though it is too late this season as crab grass has already germinated. An application may prevent some other weed seeds from germinating and the nutrient value will certainly not go to waste. Note: Corn gluten also prevents grass seed germination.
- Overseed. Spread triple mix or lawn soil over areas where bare patches occur and apply quality grass seed by hand at the rate of 500 grams per 40 sq meters. Rake smooth, step on it to bring the soil and seed in firm contact, and water well until the roots have taken firm hold. Remember that a thick lawn is your best defence against weeds.
- Water less. As we approach the summer season, the temptation to get out the lawn sprinkler will pull at you. I urge you to hold off until there is a real need. A lawn will grow nicely without water for up to 7 days. If it hasn’t rained for a week by all means give your lawn a drink and apply about 2 cm to make sure that it moves down to the root zone where it is really needed. Keep in mind that a lawn that is never watered will generally live in our Ontario climate, though it will not thrive through a drought.
- Don’t water. If we get into a drought situation, forget about watering all together. Your lawn will stop growing and it may go brown, but for the most part it will be dormant, not dead. That is, unless the drought continues for 4 weeks or longer at which time my theory of ‘dormant not dead’ could prove erroneous. I argue that watering at that point is not going to solve the problem of dead grass. See below.
If you do experience dead areas in your lawn this summer, plan on overseeding in mid August. By late September your grass will have revived and will be looking good again.
The lawns that we grow here are a cool weather crop. That is why there is more sod grown per capita in Ontario than anywhere in the world. We do it because we can.
We have fabulous golf courses, partly for this reason, also.
Back to water. The Turfgrass Water Conservation Alliance has focused on identifying grass types that perform under the most demanding conditions of heat and drought. What is emerging is the introduction of new varieties that use 30-40% less water. Some of these new grass varieties are already being grown by sod growers: you may have some growing in your yard right now. In coming years these new grass seed varieties will be common place wherever bagged grass seed is sold.
Looking in the crystal ball of grass seed production and hybridizing, we see self-repairing, rapidly establishing turf that will free up home gardeners to play more golf or enjoy other forms of gardening.
Dr. Chris Murray from LakeheadUniversity recently completed an exhaustive review of research concerning lawn health and water pollution. He concluded that a lawn that is properly fertilized (and cut high) significantly reduces the amount of runoff from a lawn. He has determined that turf grass is one of the best environmental landscapes to limit runoff pollution and improve storm water retention.
Final note: if you have racoons or skunks digging up your lawn, you likely have grubs feeding on grass roots. June is the month to apply dormant nematodes, available from garden retailers. Water these microscopic insects into the soil thoroughly after application for best results.
Question of the Week
Q/ Is it true you have a new gardening book out this spring? Where can I buy it?
A/ My eBook is available through Star Dispatches.com. It’s called ‘Horticultural Domination: Growing the best lawn and garden on the block’. Single copies of my eRead can be purchased for $2.99 at http://stardispatches.com/single.php?id=34 or you can subscribe to StarDispatches.com for only $1/week.