Maintaining and Sustaining

Mowing, watering, or applying pesticides incorrectly can lead to problems for Lake Whatcom. Tweaking your techniques could promote healthier water and grass.

Mowing
In general, don't remove more than one-third of the grass blade at one time. If over one-third of the blade is removed, the grass becomes nutrient and water stressed. Most lawns in this area are fescues and ryes that should be mowed to 2". Bentgrass lawns, often present in older landscapes, should be mowed at a height of 1" for optimum health. Find out what kind of grass you have for precise recommendations and don't forget to sharpen mower blades two or three times each season.

Grass clippings are best left on your lawn where they'll provide 20-30% of needed nitrogen. If clippings are wet and clumpy, knock them apart so grass underneath isn't smothered. Mulching lawn mowers are a great tool for this. Stay away from lakes or streams while mowing because if clippings fall in, their high nitrogen content will pollute the water. Be sure to sweep up any grass clippings that blow onto paved areas to keep them from washing into storm drains.

Watering
Although some people water their lawns in the summer, lawns can successfully go dormant in western Washington and rejuvenate when the rains return. Sandy soils and rye grasses may require some irrigation during dry periods. A deep watering every two weeks should be sufficient for these situations.

If you water your lawn, focus on getting the water to the roots where it is most needed. Wetting the entire root zone maintains healthy, deep roots, which promotes dense turf and improves drought resistance. Don't water more than 1/2" per hour to reduce the chance of runoff and don't water to the point that puddles form. Cans placed in sprinkler paths can be used to measure how much water is sprayed in a given time. Adjust your watering systems so they're watering turf, not pavement.

Water can also be lost through evaporation before it gets to the roots. That's why it's best to water before ten a.m., when the sun is still low in the sky. You can conserve even more water by using soaker hoses for landscape plants instead of sprinklers. These inexpensive alternatives greatly reduce runoff and evaporation problems by slowly watering directly on the ground, not through the air.

But soaker hoses don't effectively distribute water for lawns. For lawn sprinkler systems, it's best to use rotors or impact heads, not "spray heads," to reduce evaporation.

Pest Management
A healthy lawn can hold its own against pests. Tolerating some pests, such as weeds, can reduce the need for pesticides. Reducing the amount of pesticides you use on your lawn in turn reduces risks to water quality and saves money.

If you decide a pest has become a threat to your lawn's survival, try hand-pulling weeds before spraying pesticides. If using chemicals is necessary, choose pest-specific pesticides rather than broad spectrum ones and apply only to problem areas rather than to your entire lawn. Spreading a product that contains both herbicides and fertilizers-popularly known as "weed and feed"-over an entire lawn area is wasteful and not cost effective. It also increases the risk for contaminated water runoff because the chemicals are applied in excess, rather than directly to weeds.

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