Caring for Your Northwest Lawn Organically

Soil pH

The heavily wooded Northwest has fungal-dominant soil.

Here in the heavily wooded Northwest our soil is fungal-dominant, which gives it a higher acid content. Because of the acidity, the soil pH is generally low, and it is important to raise the pH level to maintain a healthy lawn. Adding lime to the soil raises the pH level, bringing it into a better acid-alkaline balance. The pH scale goes from 0 to 14, with 7 being neutral, but most soils are between 4 and 9.  Below 6.0, soil is acidic, above 7.0 it is considered alkaline. A pH between 6 and 7 is generally considered ideal.

To find out your soil’s pH level, it’s a good idea to have your soil tested professionally. If a soil’s pH is found to be lower than 6.0, then an application of lime will reduce the acidity in your soil and lead to a healthier lawn. We have found a calcitic lime product that is much faster at raising the pH level in soil. In as little as three weeks your soil’s pH can be at optimum levels.

Another benefit of calcitic lime is that it doesn’t contain any magnesium carbonate. While many lime products (such as dolomite lime) contain magnesium, it is not necessary in the Northwest since the soil usually has plenty of it. Adding more will make it worse, and cause compaction, among other things.

Mowing

Many people are under the impression that mowing your lawn shorter will mean it will take longer to grow back, allowing you to mow it less often. This is not true, and is actually harmful to your lawn for a number of reasons.

The upper blades of grass are what allow it to absorb water and sunshine, converting it to food (a process called photosynthesis). This is how all plant life gets its nutrition. If grass blades are trimmed too low, this process is compromised and the grass begins to starve. This triggers the grass to grow faster so it can get back to ‘normal’. While expending all this energy to regrow quickly, it weakens the grass. Add to that a lack of water or sunshine, and the grass begins to stress and die.

By setting your mower at the highest cutting height, you trim off less of the important blades that the grass needs for processing sunlight and water into food. Another benefit is that as taller blades, it can win the battle against weeds, which can thrive more effectively in a shorter environment. If the grass is short and weak, it will lose the territorial battle and the weeds will take over the lawn.

Fertilizing and Watering

 

Use organic fertilizer only.

Use only organic fertilizers on your lawn. Fertilizers loaded with pesticides and other toxins will build up in your soil and affect it adversely. The runoff goes down the storm drains and into the water system, poisoning the environment. Using organic fertilizer twice a year (spring and fall) is all your lawn needs to do well.

When watering your lawn, it’s important to give it just the right amount of water. Overwatering can be as bad as under-watering. We get plenty of moisture nearly year-round in the Northwest, so it’s not necessary to water your lawn constantly. Not only is this a waste of water, but too much can drown the grass and cause loss of nutrients through soil erosion. If it hasn’t rained for a few days, and you see your lawn getting a little stressed, put a cup in your sprinkler zone. Once it gets about an inch of water, that’s enough.

If you have any questions about organic lawn care, Hedahl Landscape is a Certified Sustainable Landscape Professional, EcoPRO certified. They would be happy to answer and questions you may have, or provide a free estimate for your lawn. Call us at 360-340-1141 or visit our website at www.hedahlandscape.com