Are you ready to stop PULLING your weeds and start PREVENTING them instead? If so, there are two essential products to add to your weed-control arsenal, namely pre-emergent and post-emergent. So, what’s the difference? The easiest way to keep these two products straight is to break the names down to their roots, pre or post, meaning before or after, and emergent, meaning at the time of sprouting. A pre-emergent is used before your weeds “emerge,” or sprout, and a post-emergent is used after they have already sprouted.
There are many ways that weeds make their way into your garden, be it hitch-hiking seeds stuck to your pant-leg, “deposits” left by birds or other animals, seeds carried by wind, or tiny weeds hiding in nursery pots. Just because you didn’t have a problem last year does not mean the same will be true this year. Weeds always find a way. An annual application of pre-emergent each spring will help ensure that any stray seeds that made their way into your yard are not able to sprout into full-grown, rapidly-reproducing weeds.
Pre-emergent weed controls work by creating a chemical barrier in the top layer of soil that prevents seeds from growing roots and shoots. Maintaining this barrier is important, so be sure to apply the pre-emergent as your final step. That is, if you need to pull weeds, plant new shrubs, install grass plugs, or plan on disturbing the soil in any way, apply the pre-emergent afterwards so the chemical barrier stays in place near the soil surface.
When deciding when to apply pre-emergent, early is better than late; one to two weeks before weed seeds begin to germinate is ideal. Pro-tip: as soon as you see weeds in your lawn this year, set a reminder in your calendar (2 weeks early) for next year; this way you will have a good idea of when to apply next time! This year, go ahead and apply as soon as possible and again every 60-90 days thereafter. During the rainy season, you can apply pre-emergent more often as the product is more likely to get washed away.
Pre-emergents may be used year-round with no temperature restrictions (just avoid using them in the veggie garden). Even though you can’t see them, it is always easier to kill your weeds before they sprout and begin to spread. The most effective pre-emergent for most of the weeds in our area is known as Dimension. This granular product is easy to spread and safe for use within flower beds. Alternatively, you can use liquid Atrazine which also kills tender recently-sprouted weeds but is for use on lawns only, not flower beds.
Crabgrass and Dollarweed can be a bit harder to eliminate, so you’re better off using a more selective pre-emergent or post-emergent for these weeds, specifically Hi-Yield Crabgrass Control and Fertilome Dollarweed Control.
What if you missed the boat and you have already-sprouted weeds to contend with? This is where post-emergent controls come into play. Right now, you should be using WeedFreeZone on any weeds that have already sprouted with repeat applications every 4 to 6 weeks. This product is only recommended until temperatures reach 85 degrees on average, so the sooner you treat, the better! If you prefer a granular product for ease of application, you can use Weed-out granular for all varieties of grass except St. Augustine, although it does take a bit more time to take effect than WeedFreeZone.
Your Spring Weed Control Toolkit
Dimension Pre-emergent
- For use on lawns and flowerbeds
- Prevents seeds from sprouting
- Use every 60-90 days
- For year-round use
- Rent a spreader for $1 with purchase
- Avoid disturbing soil after application
- 12 lbs. treats up to 3,500 to 5,000 sq. ft.
Atrazine Pre-emergent
- For use on Centipede & St. Augustine lawns only
- Prevents seeds from sprouting and kills tender weed sprouts
- Water lawn thoroughly, wait 24 hours, apply Atrazine, re-irrigate one week later
- Apply in fall & spring while temps are below 85° F
- Avoid disturbing soil after application
- 4.3 fl oz per gallon of water treats 500 sq. ft. area.
Crabgrass Control Pre-emergent
- For use on lawns
- Prevents seeds from sprouting
- Rent a spreader for $1 with purchase
- Apply every 70 days
- For year-round use
- 35 lbs. treats up to 20,000 sq. ft.
Weed Free Zone Post-emergent
- For use on lawns, excluding Bitterblue
- Do not use near ponds
- Kills existing weeds
- Use every 4-6 weeks while temperatures are below 85° F
- Delay mowing until at least 2 days after applying
- 2 oz per gallon treats 1,000 sq. ft.
Dollarweed Control Post-emergent
- For use on lawns
- Kills existing weeds
- Use in spring & fall when Dollarweed is present
- Rent a spreader for $1 with purchase
- 17 lbs. treats up to 5,000 sq. ft.
Weed-Out Post-emergent
- For use on lawns, excluding St. Augustine
- Kills existing weeds
- Use every 4-6 weeks while temperatures are below 85° F
- Wet lawn, apply, & water 24 hours later
- Rent a spreader for $1 with purchase
- 20 lbs. treats 5,000 sq. ft.
All of these products are available at Esposito Garden Center off of Capital Circle NE. If you have any further questions regarding weed control or gardening in general, feel free to give us a call at 850-386-2114. 
Shannon Ruark
Esposito Garden Center
