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Winterproof your lawn

COOLER days and lots of moisture means the grass will be growing again after the summer's heat and there's a lot to do with the lawn to get it ready for winter.

COOLER days and lots of moisture means the grass will be growing again after the summer's heat and there's a lot to do with the lawn to get it ready for winter.

For the lawn lovers out there fall is definitely the season of the lawn but not all lawn care activities should be carried out aggressively in fall.

If you need a new lawn and cannot wait until spring then I recommend installing roll-on turf, versus installing a seed-sown lawn. Lawn seed needs 10 to 14 days to germinate and then the grass needs a further three to four weeks to establish to a point where it can withstand winter rain and snow. So fall's short season is not an ideal time to plant a new lawn using seed.

Roll-on turf by comparison already has a reasonable root system and established top growth, so if you plant it early enough it will root and establish before winter starts. The same rules apply to overseeding to fill in holes in the lawn.

Most knowledgeable turf managers will recommend fertilizer applications in the fall to help strengthen roots and to increase food reserves but not necessarily to force new, soft, grassblade growth which will be damaged by frost. Although fall fertilization is a contentious issue for permaculturists and organic gardeners, turf scientists have partially demonstrated that fall fertilization of the lawn will help the lawn withstand winter stress and allow a quicker green up in the spring. This occurs because during the cool temperatures of fall, lawn grass puts energy into root growth and carbohydrate storage with less energy devoted to blade growth; how, when and why this happens is still in debate. What's important is to apply the correct type of fertilizer and the correct amount.

If you feel the need to feed your lawn this fall, I recommend applying a small amount of fertilizer, and I mean small - more is not better at this time of year. Use a fertilizer with a 3-1-2 ratio that contains major and minor nutrients, in slow release form. Micro-nutrients (copper, zinc, magnesium, etc.) are important to give the lawn a balanced diet. As an example, a fertilizer that reads 12-4-8 or 24-8-16 (a 3-1-2 ratio) plus micronutrients is far better than a fertilizer that is 20-20-20 (no ratio just piling it on with no balance in ratio). A 3-1-2 ratio has been shown by scientific research to be compatible with how plants take up nutrient ions as 3 parts nitrogen, 1 part phosphorus and 2 parts potassium. The other important factor for fall lawn fertilization is equipment calibration, not that many people actually calibrate their fertilizer spreaders, but it is important. If you over-fertilize you waste money, force new soft growth on the lawn and the excess fertilizer leaches into groundwater and oceans causing a whole bunch of fertilizer toxicity problems. I am not going to get into the specific fall fertilizer blends or recommended application rates (they are low), so ask your turf specialist and if they don't know what you are talking about, you've got the wrong turf specialist.

Many lawn lovers also recommend arbitrary liming in the fall to adjust the lawn's pH, but without an accurate pH test, it's really just a shot in the dark and a waste of money. So test your pH first or don't lime.

Fall turf aeration is probably the most valuable turf maintenance techniques that can be done in our climate to stimulate blade and root growth, relieve compaction and aid drainage. However, only use a core-aerator type of machine that pulls out a core of soil, always fill in the core holes with topdress material and do not turn the turf into Swiss cheese while aerating. Run the machine in two opposite direction to be thorough, then stop.

If you do not want to fertilize chemically, apply an organic topdress medium like manure or compost to fill in the holes after aeration is done.

Much is written about using sand to topdress lawns to increase drainage, but using the wrong type of sand will plug the pore space (breathing space) in the soil and cause the soil to hold more water than not applying any sand.

The correct type of sand to use is coarse and angular like fill sand, washed engine sand or concrete sand. All other sands that are so lovingly screened down to the uniform consistency of flour are absolutely useless for any horticultural work except mortaring bricks together.

The fall mantra for lawns is no seed - roll on instead, aerate, topdress, fertilize organically with manure or lightly with chemical fertilizers and cut the lawn a little longer to allow the roots to dig deep.

Todd Major is a journeyman horticulturist, garden designer, writer, consultant and organic advocate. For advice contact him at stmajor@ haw.ca