Weed control is usually high on the to-do list for spring gardeners here in San Antonio. While a regular schedule of fertilizing your turf can help immensely in choking out weeds, but sometimes extra help is needed for these pesky lawn invaders. Treatment for weed control and prevention is a timely garden task. Weed pre-emergents prevent the seeds of weeds from germinating. Applying weed pre-emergents is one of the best ways to eliminate weeds and prevent them from stealing your turf’s vital nutrients out of the soil.

Pre-emergents are products used to prevent new weed seeds from germinating. They do not treat/get rid of the existing weeds in your turf. Be sure to read the label of the product you are purchasing to know specific weeds targeted and application directions (some require follow up, or extra bags to cover your area). The following is a guide for when you likely need to apply your weed pre-emergent prevention:

When To Apply Pre-Emergent Weed Control Products

  •  Mid to Late February: Keep a watch on the weather. If cold weather is prolonged, you’ll need to wait awhile for a warm break to apply for spring. Apply pre-emergent granular herbicides that are formulated for preventing the common grassy weeds that pop up in spring.
  • May-Early June – One more application of a grassy pre-emergent product can keep fall weeds at bay. Hi-Yield Turf & Ornamental Weed & Grass Stopper with Dimension, Hi-Yield Crabgrass Control .
  • Mid September – Early October –  After the first decent rain in September, you can apply a pre-emergent granular herbicide with ingredients meant to ward off broadleaf weeds that we experience popping up in late winter/early springtime.

7 Examples of Weed Control Pre-Emergent Products

  • Crew
  • Hi-Yield Turf & Ornamental Weed & Grass Stopper with Dimension
  • Hi-Yield Crabgrass Control 
  • Gallery (focus on broadleaf weeds)
  • Bonide Weed Beater Complete (Pre and post emergent product in one. Great product when used early in spring. Later applications in warm weather can turn turf yellow for awhile, but this is easily remedied through fertilization of turf).
  • Fertilome Crab Grass Preventor Plus Lawn Food (20-0-3 with Dimension, good weed and feed for early spring). We generally don’t recommend Weed and Feed products, but this one is ok for early spring.
  • Organic Weed Pre-Emergent: Espoma has an Organic Weed Preventer made with corn gluten meal.
Bag of Crew weed preeemergent prevention

Post Emergent Weed Control

Weed control post emergent products are applied after the weeds have already developed. These products usually consist of a liquid form applied by a spray applicator. Generally, we don’t recommend these types of products but for spot application to weeds.

It’s imperative to be very selective when choosing a post emergent. Make sure the label clearly states that they are safe for your particular variety of turf. Even if it is labeled safe for your turf, keep in mind that you shouldn’t be spraying these products in the heat of the day as they could still cause your lawn to burn. Only spray during early morning or late evening.

4 Examples of Weed Post Emergent Products

  • Ortho Weed B Gone For Southern Lawns (liquid formula)
  • Hi-Yield Atrazine Weed Killer (liquid formula)
  • Bonide Weed Beater Complete (Granular pre and post emergent product in one. Applied in warm weather can turn St. Augustine yellow for awhile, but this is easily remedied through fertilization of turf).
  • Hand Pulling is not the most fun way to rid yourself of your weed problem, but it is the cheapest; and when employed early, can be one of the most effective ways to control weeds after the fact. A little elbow grease and some extra time pulling weeds while they are young and few, will save you the pain of pulling weeds when they have deep tap roots and are taking over. Old forks and thrift store bbq utensils can work wonders at pulling those stubborn weeds.

Visit our lawn care page for more helpful info on building healthy turf.

~The Happy Gardener, Lisa Mulroy