The Highland Lakes area sits in a climate zone where weeds grow for nine or ten months of the year. You deal with cool-season weeds in winter and spring, warm-season weeds from late spring through summer, and a second wave of cool-season germination in fall. A bag of weed-and-feed from the hardware store is not designed for this environment, and spraying once a year and hoping for the best almost never holds.
Quick answer
Effective weed control in central Texas requires pre-emergent applications timed to germination windows in fall and early spring, post-emergent treatments for weeds already growing, and consistent follow-through through the season. One-time sprays knock back what is visible but do not prevent the next flush from germinating.
Dealing with this right now?
Tired of weeds taking over your Hill Country lawn? ACI Pest & Lawn's five-visit program hits both the cool-season and warm-season weed windows in the Highland Lakes area. Request a service visit and we'll take a look at what you're dealing with.
See how we handle it on our lawn page.
Pre-Emergent vs. Post-Emergent: The Core Difference
Pre-emergent herbicides form a barrier in the soil that prevents weed seeds from germinating. They do nothing to weeds already growing. Timing is the whole game: apply too early and the product breaks down before the germination window; apply too late and the seeds are already past the point where the treatment affects them.
Post-emergent herbicides target weeds that are already up and growing. Selective post-emergents kill specific types (broadleaf weeds, for example) without harming turf grass. Non-selective products kill everything they contact. The right product depends on what is growing and what type of lawn you have.
Timing for the Hill Country
Fall pre-emergent application (typically September through October) targets winter annual weeds like annual bluegrass and henbit before they germinate. This is one of the most skipped applications and one of the most important, because the weeds that germinate in fall are the ones that fill a lawn through the mild Hill Country winter.
Spring pre-emergent (typically February through March) targets warm-season annuals like crabgrass and spurge. The standard timing guide used by Texas extension offices keys on soil temperature, specifically when soil temperatures reach 50-55°F consistently. In central Texas, that window comes earlier than in most of the country.
Broadleaf post-emergent applications during the active growing season address weeds that made it through or came in after pre-emergent. Spot spraying visible weeds is most effective when weeds are actively growing and not under drought stress.
Common Weeds in Highland Lakes Lawns
St. Augustine and Bermuda are the most common grass types in this area, and each has different tolerances to herbicides. What you can spray on a Bermuda lawn without damage is not always safe on St. Augustine, so product selection matters.
Common weeds in the area include: dallisgrass (perennial grassy weed, very difficult to control selectively in Bermuda), nutsedge (looks like grass but is not, hard to kill), dandelions, clover, and spurge. Sticker burrs (sandburs) are a warm-season annual that comes up in dry, sparse areas and are easier to prevent with pre-emergent than to eliminate once present.
- Dallisgrass: perennial grassy weed with coarse, spreading blades and distinctive seed heads. Very hard to kill without harming surrounding turf.
- Nutsedge: fast-growing, triangular-stemmed, lighter green than turf. Spreads by underground nutlets as well as seed.
- Sticker burrs (sandbur): produce sharp burr seed heads that stick to pets and clothing. Pre-emergent in early spring is the most effective approach.
- Dandelion and clover: broadleaf weeds controlled by selective post-emergent herbicides during active growth.
Why Skipping a Service Sets You Back
Each skipped pre-emergent application allows a new cohort of weed seeds to germinate. Those plants set seed before the next treatment goes down, adding to the seed bank in your soil for the following year. The practical effect is that a consistently treated lawn gets easier to manage over time, while an on-and-off approach often stays frustrating because the seed bank never depletes.
At ACI Pest & Lawn, our lawn program runs five visits per year, timed to hit the pre-emergent windows for both the cool-season and warm-season weed cycles. Each visit includes a post-emergent application where needed for what is actively growing. Staying on the program is what makes the improvement visible by the second and third year.