Almost time to de-thatch!
St. Augustine grass (Stenotaphrum secundatum) is coming out of its winter dormancy and beginning to revive as the weather warms. The return of warm weather means it’s time to take a close look below the surface to see if the lawn has reached at unacceptable level of thatch. Thatch is organic matter like leaves and grass clippings that have accumulated at soil level but have not fully decayed. This accumulation of thatch prevents moisture, air, and fertilizer from reaching the roots, causing grass to become weak and subject to pests and disease as the growing season progresses. Part the blades and take a look. If the thatch is more than 1/2” thick, it’s time to remediate.
De-thatching is done by combing the lawn vigorously with a stiff-tined rake or mechanical de-thatcher. Remove the thatch and as little of the grass itself as possible. New shoots will shortly appear. The best time to de-thatch - June and July when the weather is warm and growth is vigorous.
St. Augustine grass is native to the Gulf of Mexico, the West Indies and West Africa, growing along sandy beach ridges, limestone shorelines, and salty and fresh water marshes. St Augustine thrives in warm weather, bright sun, and moist soil in regions of mild winter temperature. These lawns brown in winter and so are often over-seeded for a green winter appearance, although a much more water saving approach to browning would be to use lawn dye (also known as turf colorant) to maintain St. Augustine’s green appearance.
Because it spreads via the rooting of horizontal above-ground stems called ‘stolons’, St Augustine can be invasive -although nowhere near as invasive as similar grasses like Bermuda and Kikuyu. And although St. Augustine lawns cannot be called water-saving, some of the newer varieties, like ‘Palmetto’, are a bit less thirsty than the traditional kinds.
“Palmetto” St. Augustine: http://www.american-lawns.com/grasses/palmetto.html
UC Davis IPM page on St. Augustine: http://www.ipm.ucdavis.edu/TOOLS/TURF/TURFSPECIES/staugust.html
Article on positive environmental impact of turf colorants:
Google store page for lawn colorants: