August 15, 2012
The landscape industry is experiencing one of the worst summers of drought in history.

And it appears there is no relief in sight. Dave Phillips, Environment Canada’s senior climatologist, says the long-range models are not encouraging. He has said, “We’re showing warmer and drier than normal right through to Labour Day. So the situation may get worse before it gets better.”

In the Toronto area, the average temperature between March and July was 15.2°C (the highest since records began). The previous average high was 14.7°C in 2010; the normal average is 11.5°C.

The average temperature over the past 12 months in Ottawa was 8.5 C. Normal for that period is 6.2 C, and the previous warmest was 8.2 C in 2005-06. Over the same year-long period, just 619 millimetres of rain and snow fell, which is barely two-thirds of the normal amount, and 12 millimetres short of the previous record low in 1960-61.

Pam Charbonneau, turf specialist with the Ministry of Agriculture, Food and Rural Affairs, says non-irrigated turf is dormant, with the only exception being turf in the shade.

On a positive note, there is a lot of drought research being conducted at the Guelph Turfgrass Institute. With the lack of rain, Charbonneau says the results should be very interesting.

Kyle Tobin of LawnSaversPlant Health Care of Toronto agrees that non-irrigated lawns are well into dormancy. He appeared on CTV News advising homeowners to make sure if they water, to commit to it, in order to not waste reserves, and having the turf go back and forth from dormancy. He advised consistently watering1-1.5 inches every week.

Charbonneau offered some key suggestions when conditions are so dry:
  • Letting a lawn go dormant is ok. The length of time a lawn can be dormant without killing the turf depends on grass species, soil type, depth of topsoil, exposure (sun vs. shade), slope, etc. A lawn can usually be dormant for four to five weeks without losing grass. As we move beyond that to the six to eight week mark, expect to see some irreversible damage.
  • A dormant lawn is fragile. Make sure you keep traffic off of it and stop mowing or fertilizing.
  • If you are letting a lawn go dormant, commit to doing that. Bringing a lawn in and out of dormancy is very hard on it and exhausts its carbohydrate reserves.
  • Once we get beyond the six week mark without water, it might be a good idea to give dormant turf a light watering of roughly one cm every three or so weeks to help it survive. This amount of water will not bring it out of dormancy, but it will help it survive a long dormant period.

Charbonneau says she expects to have more information on the best species and cultivars for drought tolerance, which will hopefully provide more drought tolerant options for their lawns, including more drought tolerant Kentucky bluegrass cultivars and tall fescue.