St. Augustine Dethatching Guide
St. Augustine is a moderate thatch producer. Dethatch only when the thatch layer exceeds 3/4 inch — some thatch is beneficial for moisture retention and insulation. Timing: late spring to early summer ONLY, when the lawn is actively growing and can recover. NEVER dethatch during dormancy, fall, or winter. Use a BLADED dethatcher or vertical mower set to cut into the thatch layer, NOT a prong-type rake dethatcher. St. Augustine spreads by stolons only — prong-type dethatchers rip out stolons and cause severe damage that takes months to recover. Set vertical mower blades to 1-inch spacing. Follow dethatching with fertilizer and consistent watering to promote stolon regrowth.
Frequently Asked Questions
How often should I dethatch St. Augustine?
Only when thatch exceeds half an inch. Check annually by cutting a small wedge. St. Augustine produces less thatch than zoysia but more than centipede.
What type of dethatcher should I use?
A bladed or flail dethatcher only. Never use a prong-type dethatcher on St. Augustine — it spreads by stolons only, and prongs will rip them out. Recovery from stolon damage is very slow.
When should I dethatch St. Augustine?
Late spring to early summer when the grass is actively growing. Never dethatch during dormancy, during drought stress, or in fall when Large Patch risk is high.
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