By Ron Alexander
Spring is around the corner, and turf professionals and homeowners alike are wondering how best to jumpstart their lawns. Let me suggest a more natural means of managing the nutritional needs of your lawn this spring, while reducing dependence on chemical fertilizer (and improving soil conditions, which will improve your success in the short and long term). Established lawns can be managed using primarily slowly releasing forms of nitrogen and phosphorus. When applying fertilizer in this way, smaller amounts of fertilizer are often required because less is usually lost through leaching or runoff.
Remember, slowly releasing forms of nitrogen and phosphorus (like those in Bloom products) are made available to plants through microbial activity. These soil microbes are more active when plants are actively growing, being related to soil temperature, and they can pragmatically release nitrogen and phosphorus from soil and organic matter particles, making it available to plants.
Now, if one of your goals is to use less chemical fertilizer to manage your lawn or the turf you manage, and you live in areas like the DMV where cool-season turf predominates, then first make sure to:
- Improve soil conditions during turf establishment. This will allow you to increase the organic matter content of the soil, improving soil structure, microbial activity, and nutrient usage efficiency. Note that if you use a Bloom product to improve your soil conditions, it can provide significant volumes of slowly releasing nutrients (see below).
- Make sure that the soil pH is 6.0 to 7.0, which is the pH that allows cool season grasses to most efficiently uptake nutrition.
- Properly mow your grass – trying to keep your lawn at 2.5 to 3 inches in height and not to remove more than one-third of the grass blade height at any given time. This helps the lawn grow a stronger root system, and better resist disease and weed pressure. Proper mowing also allows you to recycle most, if not all, of your clippings – and their nutrients — back onto the lawn (using a mulching mower). Never mow at times of excessive heat or drought; it puts too much stress on the grass.
- Properly water the turf throughout the year. How to do this depends on many factors (site, soil, grass species), which cannot be addressed in this article.
- Control weeds, which can rob nutrition from your grass (and are often considered to be a sign of infertile soil or stressed turf).
It is commonly understood that cool-season grasses require 4 to 6 pounds of nitrogen per 1,000 ft 2 per year, which is often applied in two to four applications per year (depending on the type of fertilizer used and a person’s time commitment to turf management). Fertilizer is best applied during the active growing season, generally avoiding application during the summer and winter months.
New lawn establishment or renovation: Apply 1 inch (135 cubic yards (CY)/acre or 3 CY/1,000 ft 2 ) of Fresh Bloom or 2 inches (270 CY/acre or 6 CY/1,000 ft 2 ) of Woody or Sandy Blend and incorporate it into the top 6 to 8 inches of soil. Follow this by smoothing the planting area, adding the seed or sod, and watering. At these application rates, the Bloom products will provide adequate nitrogen and phosphorus for two years of turf growth. Only apply additional nitrogen if the turf starts to becomes a yellow-green in color.
Turf maintenance: Top dress existing turf with a Bloom product and water it in (water to assure that the product reaches the soil). This should initially be completed in the spring and the fall, watching turf color to determine if a third application is warranted. Four 25-pound bags of Cured Bloom (25 pounds per bag x 4 = 100 pounds of product) will provide approximately 1.5 pounds of slowly releasing nitrogen, as Cured Bloom has a 1.5-1.5-0 guaranteed analysis. If you choose to use the Bloom Woody or Sandy Blend instead, remember that they contain fewer nutrients by volume than Cured Bloom. So, adjust your application rate, accordingly, applying a 25% greater volume of Woody Blend and double the amount of Sandy Blend for a similar nutrient addition.
In most cases, applying 1.5 to 2.25 pounds of nitrogen per 1,000 ft 2 of turf area is a good initial application rate. So, apply 4-6 bags of Cured Bloom per 1,000 ft 2 of turf area (or 10 to 15 pounds per 100 ft 2 ), 3 to 4 cubic feet of Woody Blend or 5 to 6 cubic feet of Sandy Blend to supply a similar amount of nitrogen per 1,000 ft 2 of turf area.
Try this natural approach for a year and watch how your turf (and soil) responds!