We stock MicroLife because it’s organic, slow-release, won’t burn your lawn, and is safe for kids and pets almost immediately after application — but the formula and timing still matter a lot in Central Texas, where alkaline soil, heat stress, and fall fungal disease all shape what your lawn actually needs. Here’s how to time it right.
The Two Rules That Apply to Everything
Before getting into specific products, two rules apply no matter which MicroLife formula you’re using or which grass you have:
- Only fertilize actively growing grass. Soil temperature should be consistently above 65°F. Fertilizing dormant winter grass doesn’t help it and can encourage weeds instead.
- Stop nitrogen applications by the end of August. Late-season nitrogen pushes tender new growth right before the first cold snaps of fall, and that new growth is the most likely to get damaged.
New Sod: Wait 30 Days
If you just had sod installed, don’t fertilize for the first 30 days — new roots can be damaged by fertilizer, even a gentle organic one. After a month, apply MicroLife Multi-Purpose 6-2-4 at half the label rate for the first feeding. Never use a weed-and-feed product on new sod; the herbicides in those products stunt root development right when your lawn needs to be rooting fastest.
A Season-by-Season Schedule for Established Lawns
Late February–March: First application of the year, timed to your second mow once the lawn is actively greening up. MicroLife Multi-Purpose 6-2-4 works across all three grass types (Bermuda, St. Augustine, Zoysia) as a general-purpose starting point.
May–June: For Bermuda lawns that want faster green-up and more vigorous growth, switch to MicroLife Hybrid 20-0-5 — its higher nitrogen content is well suited to Bermuda’s aggressive growth habit. St. Augustine and Zoysia lawns can stay on Multi-Purpose 6-2-4.
Throughout summer, as needed: If your grass is yellowing despite regular watering and fertilizing, it’s often iron chlorosis rather than a nitrogen problem — a common issue in Central Texas because of our alkaline soil. MicroLife Acidifier 6-2-4 lowers soil pH and adds iron, which is usually the fix. It’s also useful if your irrigation water runs high pH, which offsets some of what a normal fertilizer application does.
August: Repeat the May–June application (Hybrid for Bermuda, Multi-Purpose for St. Augustine/Zoysia) — your last nitrogen application before the fall cutoff.
September: This is a critical month for disease prevention, not growth. Apply MicroLife Brown Patch 5-1-3 proactively for St. Augustine and Zoysia lawns before the fungal disease season starts. Brown patch and large patch both show up as nights start cooling while soil is still warm and humid — exactly the conditions Central Texas gets every fall. Brown Patch 5-1-3 also functions as a complete fertilizer, so it’s doing double duty.
October–November: Shift focus to soil health rather than growth. MicroLife Humates Plus 0-0-4 is a concentrated soil conditioner that’s especially useful across Central Texas soils — whether you’re dealing with dense Blackland clay on the east side of the metro or thin, rocky caliche over limestone out toward the Hill Country. Either way it loosens compacted soil, builds stronger root systems, and helps your lawn store water more efficiently heading into winter. If you just had sod installed on a rocky, freshly-graded lot, this is also a good window to add MicroLife Mycorrhizal Plus — a biological root inoculant that’s especially useful for new roots trying to establish in thin Hill Country soil.
December–January: No fertilization. Your lawn is dormant or close to it, and feeding it now doesn’t help.
How Much Nitrogen Does Your Grass Actually Need?
The schedule above is the same shape for every lawn, but the total amount of nitrogen your grass wants over a full year is different by grass type:
- St. Augustine: 2–3 lbs of nitrogen per 1,000 sq ft per year. Apply every 6–8 weeks through August, and use iron supplements (Acidifier) if you see yellowing rather than adding more nitrogen.
- Bermuda: 3–4 lbs per 1,000 sq ft per year — the highest of the three. This is why Hybrid 20-0-5 exists; Bermuda genuinely uses more nitrogen than the other grasses and Multi-Purpose alone often isn’t enough to keep it looking its best.
- Zoysia: 1–2 lbs per 1,000 sq ft per year — the lowest by a wide margin. Over-fertilizing Zoysia doesn’t make it greener, it just builds excess thatch and raises disease risk. If your Zoysia looks thin, the fix is almost never “more fertilizer.”
Quick Reference by Product
| Product | Best For | When |
|---|---|---|
| Multi-Purpose 6-2-4 | All grass types, general feeding | Feb–Aug, every 6–8 weeks |
| Hybrid 20-0-5 | Bermuda, faster green-up | May–Aug |
| Acidifier 6-2-4 | Yellowing grass, alkaline soil | As needed, spring–summer |
| Brown Patch 5-1-3 | St. Augustine & Zoysia disease prevention | September |
| Humates Plus 0-0-4 | Clay soil conditioning, root health | Oct–Nov |
All of these are in stock at Castillo Grass in bags and jugs, and we deliver across Austin, Round Rock, Cedar Park, Pflugerville, Georgetown, Kyle, Buda, and Leander. Browse the full MicroLife lineup, check our Lawn Care Guide for grass-specific fertilizing schedules, or get a quote and we’ll help you figure out exactly what your lawn needs right now.