Is Fall pre emergent weed spray really necessary in Carlsbad and the temperate climate of Southeast New Mexico?
Actually, we consider our Fall weed control program to be the best treatment we put down all year. In Carlsbad, this is especially true since our Fall season tends to be long and warm where a lot of weed seeds have time to germinate.
While it is good practice for all lawn types, in Carlsbad, it is especially true for warm season grasses like Bermuda and St Augustine that go dormant in the Winter.
Why In The Fall?
A fall pre emergent application is generally targeted toward cool weather annual broadleaf weeds that thrive in Winter and Spring. The seeds from these plants have been lying dormant in the ground since last Spring and will start to germinate in early Fall when the night time air temperature drops to and below 75 consistently. See the best time to spray for weeds in Carlsbad. This is usually in mid to late September depending on the year. So to target these specific plants, you should spray in the early to mid Fall.
In the Winter lawn and especially in warm season turf lawns that go dormant, there is little competition for space and light. So without a Fall pre-emergent treatment, the weeds germinate easily and can dominate large areas if seeds are present. This has the potential to be very damaging to the lawn when Spring arrives as the emerging grass will have to compete for space and light. After the Winter annuals die off, there can be bare areas left where crabgrass and other Summer weeds can take hold.
Some of the most common and troublesome Winter and Spring weeds you'll notice in Carlsbad, Artesia, and Southeast New Mexico are Mustard (London Rocket), Henbit, Black Medic along with many others. And usually by late Fall to early Spring they will be well established and quite noticeable in dormant lawns. As the weather warms, they will flourish, re-seed, and then start to die off leaving more seeds to repeat the process next Fall.
So a Fall application of pre emergent herbicide applied before these seeds germinate will help to minimize if not completely eliminate their presence. This, in our opinion is a lot better approach than going through the same cycle year after year of waiting until they've overtaken a yard in the Spring and then addressing them.
An important advantage to adding this step to your program is in breaking the life cycle of certain species. If they can't germinate and grow, they can't re-seed and therefor become less and less of a problem to try and control. Sure, you may still get an occasional volunteer sprout here and there. However, pulling or treating a few weeds is a lot better option than dealing with hundreds or even thousands.
Now, if you're specifically targeting a plant such as Sand bur, Puncture Vine or some other Summer annual, a Fall application isn't going to help much if any as these plants don't start to germinate until the weather and ground temperature starts to warm again. In the case that these are what you're wanting to target, your Spring application followed by a mid Summer application will be more successful at addressing these.
A Consistent Weed Control Program
Creating a beautiful thick lawn is hardly ever by accident. It requires a thought out strategy of several elements that include a consistent weed control program. In most cases, one application in the Spring will not last an entire year.
While the presence of weeds is largely dependent on the health and fullness of the turf, it is a continual process to keep it that way. Your program should also include a timed fertilizer program and grub control treatments as well as pre and post emergent herbicide treatments.
Most programs for most lawns should include at least a Spring and Fall treatment. And sometimes more. Again, it depends on the condition of the turf and what specific weeds you're wanting to target. However, over time as a thicker healthier lawn is established, there may not be a need for as many treatments.
So is it necessary? In most applications, we say yes. Honestly, we feel it's the most important application of the season. It helps stop a lot of problems before they even begin. Only doing one pre emergent application in the Spring will only give control for part of the season. It is a never ending battle and continued cycle that repeats itself year after year.
So whether you do it yourself or have a weed control professional do it, consider at least a second pre emergent application in the Fall. As well as breaking the cycle of seeding and re-seeding, it will buy you some time for getting your Spring application down when things are getting busy at the first of the year.
Professional Weed Control Services
If you live in Carlsbad, Artesia, or other parts of Southeast New Mexico and would like lawn weed control service, give Horizon Pest Control a call at 575-725-9331. We can provide service to help you evaluate, plan, and get you started toward a healthier, thicker, greener weed free lawn.