North Texas Lawn Care Calendar: Month-by-Month Weed and Fertilizer Guide

Most lawn care advice you find online was written for the Midwest or the Southeast — places with predictable rain, mild summers, and forgiving soils. North Texas is none of those things. DFW and the Arlington area sit on heavy Blackland Prairie clay that swings between concrete-hard drought conditions and waterlogged monsoon weeks, all while summer temperatures routinely top 105°F. A generic lawn calendar will get you into trouble. This month-by-month weed control and fertilizer guide is built specifically for the North Texas climate and soil conditions Hamann works in every day.

January – February: Dormant Season, But Not Idle

Your bermuda and St. Augustine are dormant and brown, but winter weeds like poa annua, henbit, and chickweed are actively growing and seeding out. This is also the single best time to run a soil test. Labs are less busy, results come back faster, and you have time to act on low pH or nutrient deficiencies before the growing season demands attention. Target a soil pH of 6.0 to 6.5 for warm-season grasses in DFW clay.

• Soil testing: Collect samples from 4 to 6 spots across the lawn, mix them together, and send to Texas A&M AgriLife Extension’s soil testing lab or a private lab. Results guide every fertilizer decision for the year.
• Winter weed check: Walk the lawn and note where poa annua, henbit, or chickweed are established. Spot-treating with a broadleaf herbicide now prevents them from setting seed before spring.
• Pre-emergent planning: Map your pre-emergent application schedule. Crabgrass soil temperatures rarely hit the critical 55°F threshold in the top 2 inches until late February or early March in Arlington — but ordering product and confirming your irrigation system is operational should happen now.
• Equipment check: Service your spreader, inspect hose-end sprayers, and confirm your backpack sprayer is calibrated. A mis-calibrated sprayer causes under- or over-application errors that cost money and damage turf.

March: The Most Critical Window of the Year

When soil temperatures at a 2-inch depth reach 50°F consistently — usually early to mid-March in the DFW area — crabgrass germination is 4 to 6 weeks out. Pre-emergent must be down and activated before germination begins. Missing this window by even two weeks can mean a summer full of crabgrass that no amount of post-emergent will fully undo.

• Pre-emergent application: Apply prodiamine or dithiopyr before soil temps hit 55°F. Water in with at least half an inch — three-quarters is better on DFW clay — within 48 hours.
• Goosegrass timing: Goosegrass germinates later than crabgrass, closer to 60°F soil temps. A split application (half rate now, second half 8 to 10 weeks later) covers both germination windows.
• Broadleaf weed surge: Cool-season broadleaf weeds that survived winter are growing fast. Spot-treat dandelion, clover, and wild violet before they flower and spread seed.
• No fertilizer yet: Bermuda and St. Augustine are not reliably out of dormancy in March. Fertilizing dormant turf feeds weeds and wastes money. Wait for full green-up.

April: Green-Up and First Fertilizer

By mid-April most bermuda lawns are breaking dormancy and St. Augustine is pushing new growth. Broadleaf weeds are exploding alongside the grass, taking advantage of the open canopy before turf fills in. This is a busy month that requires keeping two programs running simultaneously.

• Starter fertilizer: A light application of a balanced fertilizer with some phosphorus supports root development during the green-up push. Don’t over-apply nitrogen this early — young turf is sensitive and excess nitrogen promotes weeds.
• Broadleaf spot-treatment: Dandelion, clover, oxalis, and broadleaf plantain respond well to three-way broadleaf herbicides (2,4-D, MCPP, dicamba blends) when temperatures stay below 85°F. Apply on a calm day to avoid drift.
• Mowing height: Drop bermuda to 1 to 1.5 inches to scalp out winter debris and encourage lateral spread. St. Augustine should stay at 3 to 3.5 inches — never scalp it.

May: Push Fertilization and Nutsedge Watch

May is the peak growth month for warm-season grasses in North Texas. Bermuda in particular can double in density with the right nutrition and water. This is the time to push a full nitrogen application and set the foundation for a dense summer turf that outcompetes weeds on its own.

• Bermuda fertilizer: Apply 1 to 1.5 lbs of actual nitrogen per 1,000 sq ft using a slow-release formulation. Slow-release sources feed evenly for 6 to 8 weeks and reduce the risk of burn during the warm days ahead.
• St. Augustine fertilizer: Use a 3-1-2 ratio fertilizer at about 1 lb nitrogen per 1,000 sq ft. St. Augustine in DFW clay often shows iron chlorosis — if you see yellowing between the veins, a chelated iron supplement fixes this faster than pH adjustment alone.
• Nutsedge watch: Yellow and purple nutsedge emerge when soil temperatures hit 65°F. Early identification is critical — nutsedge spreads through underground nutlets that become harder to control with every passing week. Halosulfuron (Sedgehammer) or sulfentrazone is the standard treatment.

June: Summer Fertilizer Timing and Heat Caution

June is transition month. Early June still allows a fertilizer application for bermuda, but once daily highs consistently exceed 95°F, nitrogen applications become a heat-stress risk. Pushing growth when the grass is already under thermal stress invites disease and root damage.

• Early June fert window: Apply the second round of nitrogen (0.75 to 1 lb per 1,000 sq ft) by mid-June if temperatures allow. After that, hold off until September.
• Nutsedge follow-up: A second halosulfuron application 6 to 8 weeks after the first targets nutlets that escaped the initial treatment.
• Irrigation adjustment: DFW clay doesn’t drain quickly. Deep, infrequent watering (1 inch twice a week) is more effective than daily shallow irrigation and reduces fungal disease pressure.

July – August: Suppression Through Turf Density

The best weed control in midsummer is a thick, healthy lawn. Fertilizer and herbicide applications are largely on hold during the peak of Texas heat. Your job is to keep the grass alive and dense enough that weeds can’t get a foothold.

• No nitrogen fertilizer: Pushing growth in 100+°F heat stresses turf and invites gray leaf spot in St. Augustine and other fungal issues. Let the slow-release from May carry you through.
• Spot-treat persistent weeds: Nutsedge, dallisgrass, and kyllinga that survived earlier treatments can receive targeted herbicide applications on cooler early-morning days when temps are below 90°F.
• Mowing height adjustment: Raise bermuda to 2 inches in July and August to reduce heat and moisture stress on root zones. Higher canopy provides its own shade.

September: Fall Pre-Emergent — The Window Most Homeowners Miss

September is the mirror image of March. Just as a spring pre-emergent blocked summer annual weeds, a fall pre-emergent blocks winter annual weeds — poa annua, henbit, and common chickweed — before they germinate in October and November. Most homeowners skip this application entirely, then spend the winter pulling weeds or watching a green carpet of poa cover their brown lawn.

• Fall pre-emergent timing: Apply before soil temperatures at 2-inch depth drop to 70°F, typically mid- to late September in Arlington. Prodiamine at a half-rate works well as a solo application or paired with a second application in early October.
• Light fertilizer for bermuda: A very light nitrogen application (0.5 lb per 1,000 sq ft) in early September supports recovery from summer stress without pushing excessive growth before dormancy. Avoid potassium-heavy winterizers at this stage — save those for October or November.
• Overseed decision: If you overseed with ryegrass for winter color, do not apply pre-emergent — it will prevent the ryegrass from germinating. Choose one or the other.

October – November: Final Treatments and Winterizer

As bermuda begins to slow and St. Augustine starts pulling back, October and November are the last windows for broadleaf weed control and the best time for winterizer fertilizer.

• Broadleaf weed treatments: Cooler temperatures make herbicides more effective and reduce turf stress. Hit henbit, chickweed, clover, and any surviving summer broadleaf weeds before they build biomass for the winter.
• Winterizer fertilizer: A low-nitrogen, high-potassium fertilizer (something like a 5-10-30 or similar) applied in late October to mid-November strengthens root systems and improves cold hardiness. This is especially beneficial for St. Augustine, which is more cold-sensitive than bermuda.
• Final mowing: Drop bermuda back down to 1.5 inches for the last mow of the season to reduce thatch and limit gray leaf spot carry-over sites. St. Augustine stays at 3 to 3.5 inches through dormancy.

December: Rest — But Plan Ahead

December is the only true off-month for lawn treatment in North Texas. Grass is dormant, weed activity is low, and your main job is keeping foot traffic off frozen or frost-heaved turf. Use this time to review what worked this year and order product for the spring pre-emergent window. The March window arrives faster than it feels like it should, and being unprepared is the most common reason homeowners end up fighting crabgrass all summer.

Read more about centipede grass in North Texas if your lawn includes unusual grass varieties that require a different seasonal approach from the bermuda and St. Augustine calendar above.