How do we get rid of dollarweed in our HOA's St. Augustinegrass common areas?

By OurHOA · General information · Revised October 29, 2026

Why dollarweed takes over HOA St. Augustine lawns, how to cut irrigation to starve it, which herbicides are safe in summer heat, and contract wording to use.

Part of the HOA board handbook: vendors, projects and upkeep.

The short answer

Dollarweed is a water meter with leaves. Clemson Extension puts it plainly: where dollarweed grows, the soil is staying too wet. Spray without changing the watering and it comes back by the next rainy season. The board's plan should run in this order: 1. Cut irrigation frequency on the infested zones and reset the controllers by season. 2. Raise the mowing height so the St. Augustinegrass shades the weed out. 3. Fix the wet spots that watering changes cannot fix: low areas, compacted soil, leaking heads. 4. Only then, have a licensed applicator spot treat with a product labeled safe for St. Augustinegrass, in spring or fall, never in the heat of summer. Mississippi State Extension also warns that complete eradication is impractical. Set the goal as turf that is mostly grass, not turf with zero dollarweed.

Confirm it is dollarweed

Dollarweed (Hydrocotyle species, also called pennywort) is a perennial with round, waxy leaves with scalloped edges, each on its own stalk. Mississippi State gives the easy field test: the stalk joins the middle of the leaf, like an umbrella. Dichondra, a look-alike, has a kidney-shaped leaf with the stalk at the notch. Clemson says dollarweed spreads by seed, by underground rhizomes and by tubers. That explains why pulling the leaves does little and why one wet corner can feed a whole lawn. Before spending money, walk the common turf and map where it grows. Dollarweed clusters along sprinkler lines, in swales, at the bottom of slopes, beside downspouts and around leaking valves. A patch that follows one irrigation zone is a watering problem. A patch in a low spot that stays soggy after rain is a drainage problem.

Fix the watering first

UF/IFAS turf specialists say overwatering promotes dollarweed and sedges, and that controllers left on one schedule all year usually end up overwatering. Mississippi State cites Florida research showing that watering less often can reduce dollarweed density. UF/IFAS gives a usable schedule for St. Augustinegrass with 6-inch roots and no rain. Days between waterings: - Winter: 8 to 28 in Pensacola, 7 to 23 in Gainesville, 3 to 10 in Miami. - Spring: 3 to 11, 3 to 9 and 2 to 7. - Summer: 1 to 5 in all three cities. - Fall: 2 to 9, 2 to 8 and 2 to 6. Each watering should put down 1/2 to 3/4 inch, which wets the root zone of a typical sandy Florida soil. UF/IFAS recommends watering when the grass shows stress: leaf blades folding lengthwise, a blue-gray tint, or footprints that stay visible. If at least 1/2 to 3/4 inch of rain falls, skip the next cycle. Mississippi State puts warm-season turf at roughly 1 to 1.5 inches of water a week in summer from rain and irrigation combined. Follow any watering days set by your water management district, city or utility, and change one thing at a time so the board can see what worked. Our guide on cutting an HOA water bill with an irrigation audit covers checking heads, zones and controller settings.

Mowing, soil and drainage

Thick, tall St. Augustinegrass is the cheapest herbicide the association will ever buy. UF/IFAS says standard St. Augustine cultivars such as Floratam should be mowed at 3.5 to 4 inches, dwarf cultivars at 2.5 inches, and Seville at 2 to 2.5 inches. Many crews mow lower. Scalped St. Augustine leaves open soil and light for dollarweed. UF/IFAS also lists dollarweed among the weeds that grow well in compacted or constantly wet soil, and says the compaction or saturation has to be addressed for weed control to last. Mississippi State adds that poor surface drainage may need renovation. For the wet spots on the map, the usual fixes are: - Repair broken heads, leaking valves and misaligned sprays that soak one area. - Extend downspouts or regrade so roof water does not pond on turf. - Core aerate compacted areas such as paths across the lawn and play areas. - For a swale that stays wet no matter what, consider a drain or replanting it with a plant suited to wet ground instead of fighting turf weeds there forever. After dollarweed is gone, fill bare spots quickly. Clemson recommends fertilizing those areas based on a soil test so grass, not the next weed, takes the space.

When herbicide makes sense

Herbicide is the last step, and the product has to match the grass. St. Augustinegrass is injured by several common broadleaf weed killers sold for other lawns. Extension services in Florida, South Carolina and Mississippi name these options for dollarweed in St. Augustine, at labeled rates: - Atrazine. Clemson rates it safe on St. Augustine and suggests up to two applications a year, one in fall and one in late spring after green-up. UF/IFAS warns that Floratam, the most widely used St. Augustine in Florida, does not tolerate atrazine applied above 85 degrees F. - Products combining 2,4-D, MCPP and dicamba. Clemson rates them intermediate on St. Augustine, calls for a reduced rate, and says not to apply during spring green-up or when air temperatures exceed 90 degrees F. - Imazaquin. Clemson suggests late spring after green-up while the weeds are small, with a second application about six weeks later. - Metsulfuron. Mississippi State lists it for St. Augustine during active growth only. Expect repeat applications. UF/IFAS says perennial broadleaf weeds usually need more than one treatment at the interval on the label, and that postemergence products work poorly on drought-stressed weeds or when the turf is mowed within a few days of spraying. Three environmental limits matter on HOA property. Clemson says atrazine and imazaquin can move through sandy soils to groundwater where the water table is shallow, so ask the applicator about soil type before using them near ponds. UF/IFAS warns that dicamba, metsulfuron and atrazine can be taken up by the roots of trees and shrubs, so they should not go over the root zones of landscape beds and trees. And UF/IFAS says weed-and-feed products only make sense when weeds cover the whole lawn evenly, which is rare. Spot treat the mapped patches instead.

A year on the calendar

A workable schedule for a Florida or Gulf Coast community. Shift the months for your area. - January to February: walk and map the dollarweed while the turf is slow. Reset controllers to winter frequency. Get quotes for drainage fixes. - March to April: fix leaks and drainage before the growing season. Raise mowing height as growth picks up. No post-emergence spraying during green-up. - Late April to May: after the lawn is fully green and before daytime highs settle above 85 to 90 degrees F, spot treat with a St. Augustine-safe product. Follow up at the label interval. - June to August: watering moves to summer frequency, but only as needed. Pause herbicide work. - September to October: second treatment window as temperatures ease. Re-map and compare with January. - November to December: reset controllers for fall and winter. Review the year at a board meeting and decide whether next year needs a drainage project.

Contract wording and the license check

Put this work in the landscape contract, not in emails. Clauses the board can adapt: "Contractor shall mow St. Augustinegrass common turf at no less than 3.5 inches. Contractor shall adjust irrigation controllers at least four times per year to seasonal schedules approved by the Association and shall report and repair leaking heads and valves within 7 days. Herbicide applications on St. Augustinegrass shall use only products whose labels list St. Augustinegrass as tolerant, shall be spot treatments unless the Association approves otherwise in writing, and shall not be made when air temperatures exceed the label's limit. Contractor shall provide the product name, EPA registration number, areas treated and applicator license number for each application." Check the license before anyone sprays. In Texas, controlling weeds around residences for pay requires a structural pest control license under Occupations Code chapter 1951. In Florida, landscape crews need a pest control license or the limited commercial landscape maintenance certification in Statutes section 482.156. In Colorado, the Pesticide Applicators' Act, C.R.S. title 35, article 10, requires a commercial applicator license. Rules and your governing documents vary, so treat this guide as education, not legal advice. Our guide on hiring an HOA landscaping contractor covers insurance and bid comparison.

Mistakes boards make

- Spraying every spring and never touching the irrigation schedule. The weed returns each year because the cause stays. - Having a volunteer spray a hardware store weed killer. Some injure St. Augustine, and nobody keeps application records. - Treating in July. Heat limits on the labels exist because the grass gets hurt. - Blanket weed-and-feed across all turf when the dollarweed sits in three wet corners. - Letting the crew mow at 2.5 inches on Floratam. - Promising owners a weed-free lawn by summer. Starving the weed with less water works slowly, so judge progress on the January map, not on one month. A short notice helps when owners ask why the sprinklers run less: "The board has reduced irrigation on common lawns to follow UF/IFAS recommendations. Watering less often, but more deeply, builds deeper roots and reduces dollarweed and other weeds that thrive in wet soil. The grass may look a little dry before each watering. That is normal. Please report broken sprinkler heads to the board." If you also have sedges in the same wet areas, our guide on controlling nutsedge in HOA common turf covers that weed.

Sources

These guides are general education for HOA boards and residents, not legal, tax, or financial advice. Rules vary by state and by your community's governing documents - check with a professional for your situation.

More on living with an hoa

Or browse all living with an hoa guides.