Maintaining a Healthy Lawn
That Green CarpetHomeowners are continually trying to maintain beautiful, weed-free grass areas. A "green carpet" enhances a dwelling and has become a matter of pride and prestige for many residents. Lawn areas are great places to sit in the summer and also provide play space for children. A lawn is a mono-culture: a culture or growth of plants of one species, usually contained within a specific area. A lawn is made up by many grass plants growing very close together. This creates some problems for successful growth and health of the plants:
Add to this the facts that:
Maintaining a lawn requires time and work because it needs regular mowing, watering, fertilizing, aerating, weeding and monitoring for disease and insect problems. In the past, pesticides have been a "quick fix" to common problems: herbicides for weed control, fungicides and insecticides for disease and insect problems. Now, the City is encouraging residents to explore alternative practices that are healthy for both the environment and residents to maintaining a lawn and garden without using chemical pesticides. Tips for maintaining a healthy lawnThe SoilSoil is the most important element for healthy grass growth. The roots of grass plants obtain needed moisture and nutrients from the soil and in order for roots to function they need plenty of oxygen in the soil. All soils benefit from the addition of organic matter which contains nutrients and improves the soil
Suggested organic matter: compost or well-rotted (or sterilized) manure Amend the soil by adding organic matter when preparing new lawn areas. For existing lawns, topdress the lawn either annually or once a month where the soil is particularly poor, applying less tan ¼ inch (less .8 cu. yds. per 1000 sq. ft.) using organic matter. Note: do not carry out lawn chores until the moisture drains from the soil….walking on a 'spongy' lawn compacts the soil. Addition of nutrientsTopdressing acts as a fertilizer supplying the nutrients needed by the grass plants. Fertilizers also provide minerals to promote green growth, root growth, hardiness and disease resistance. Small grass clippings left on the lawn will break down and provide organic matter plus they are a favorite food for earthworms. MoistureThe general rule of thumb is to give your lawn 1 inch of water, once a week; however, the details are more variable throughout the spring, summer and fall. Ideally water enters the soil and travels through it, and then drains from it. Roots absorb this moisture and also the nutrients in solution in the water. Grass root growth varies over the growing season. Grass roots are replaced continuously. Their length is a function of the rate of overall growth by the plant and grass blade length. In the spring and fall the plant is growing vigorously so the roots are also, but in the heat of summer the rate of growth slows down, in fact the plants often go dormant. From mid June to early August (generally) the roots are shallow. Therefore the recommendation for watering depends on the season. In spring and fall when the nights are cool, water deeply (2.5 cm / 1") once a week, if there is no rain. During the hot summer water more frequently but for less duration: watering that will add moisture to the top few inches of soil several times a week (always depending on amount and duration of rain). If you can, water 0.25 cm - 0.5 cm (1/8" to ¼") every few days before noon, during the hot part of summer. Applying the water during the heat of noontime decreases the stress on the plants by reducing the leaf and soil temperature while supplying water to the now shallow-growing roots. How to measure your water: Do the 'catch test'. Place a few identical-sized cans on your lawn. Turn on your sprinkler, and time how long it takes to fill the cans to the required level (for example either 2.5cms or 1/8 of an inch). Once you know how long it takes to fill the can, you can set your sprinkler timer accordingly. Porous, black soaker hoses that leak water out through the material are a good method of applying water to the soil without excess evaporation or loss to wind. They are preferable to sprinklers where the water shoots up into the air before falling to the ground. MowingKeep the lawnmower blades sharp, torn grass is more susceptible to the entry of disease organisms whereas clean cuts heal quickly. Cut about 1/3 of the grass blade off, taking more away from the plant puts it under stress and, stressed plants are more susceptible to disease. Grass plants needs ample leaves to create food by photosynthesis, so short residential lawns cannot produce enough food to be healthy. Weed seeds need light to germinate; keeping the grass 7cm in height reduces weeds. Weed-digging Hand digging weeds is an effective way to remove weeds. Pick or dig up weeds and try to remove their roots. Some weeds can be tolerated, for example, clover is now classified as a weed but used to be included in grass seed mixtures! Clover grows vigorously in the hot dry weather of mid summer shading the soil, and fixes atmospheric Nitrogen, which the grass can use. Clover mixed into the lawn benefits the grass plants. For the weeds you cannot tolerate use a 'dandelion tool'. Remember to remove the whole root system because perennial weeds will grow again if part of the root remains. AeratingThe reason for aerating is to amend compacted soil that no longer has adequate pore spaces for air and movement of water. This is most often accomplished with a machine that removes plugs of soil. In order for this process to be successful the grass must be topdressed after aeration to fill the holes in the soil with organic matter (or screened topdressing soil). Otherwise the existing compacted soil gradually fills in the holes left by the machine leaving the lawn uneven, and the walls of the cores susceptible to drying out, damaging the roots adjacent to the core holes. Fall is the best time to aerate and topdress compacted soil in Ottawa because the soil is drained, warm and the temperatures are pleasant during the day and cool at night. It is a temperate long-lasting season unlike spring, which is abrupt and often has great temperature fluctuations in Ottawa.
ThatchA thatch layer that exceeds 0.5 cm (¼ ", pencil thickness) can reduce the water entering the soil but it is extremely uncommon for homeowners to develop thatch this thick. Thatch results from cutting long portions of the grass repeatedly over the growing season. Earthworms love to eat short grass clippings but long ones dry out and do not decompose easily so build up as a layer over time. Homeowners should mow once a week so the clippings are short and attract the worms. A gentle raking in the spring to remove debris is all the lawn needs. If there is a thatch problem then topdressing is the most effective way to manage it as the thatch layer then decomposes. Reseed bare patchesWeed seeds grow well in bare spots on the lawn so repair them as soon as possible. If the soil is compacted, loosen it, add organic matter and dig it in. Sprinkle the seed on the soil surface, press it down but do not bury it, and then keep it moist until germination occurs. Try adding some Dutch White Clover to your lawn seed mixture, which is hardy and low maintenance. Ottawa has grub problems this yearA first step for lawn areas that are dead because of grubs feeding on grass roots is to identify the grub species attacking the lawn. The information on this Web site will help you identify the species and from there you can treat it. |
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