Fall Weed Spray For Spring Weeds
While this article references when to spray pre emergent weed control in Carlsbad and most of Southeast New Mexico, much of the information here is relevant to all areas. Regardless of area, the main points are -
- First identify the weed
- Understand the weed life cycle to know the best time for treatment before it germinates.
- Determine the best herbicide to use for that type of weed.
When it comes to spraying pre-emergent herbicides on lawns, proper timing is critical in consideration of the types of weeds and stickers you are trying to control. While there are some basic guidelines, good weed control or suppression with pre-emergent herbicides requires knowledge of the specific weeds you're trying to control and the temperature that they germinate. Different weeds make seed, germinate, and sprout at different times. So again, proper timing is a matter of first identifying the weed and then understanding the life cycles of the types of plants you're targeting.
The Southeast New Mexico Climate
In Carlsbad, Artesia, and all of Eddy County, the life cycle of weeds, grassy weeds and stickers are different than those from different states and geographical zones of the rest of the country. The general guidelines that suggest March and September to be the optimal time to apply pre-emergent herbicides is not necessarily accurate for all weeds or a cure all for all in these areas.
In the desert climate of Southeast New Mexico, there are some weeds that are very adaptive and will grow year round. There are Winter annuals that will sprout when the Fall weather cools and grow until it gets warm. And still there are Summer annuals that will thrive in the heat and die out when the weather cools.
Another thing to consider is, while cities like Carlsbad are central to one geographic area, they're also spread out over a large area. And in this area, there can be several different micro-climates where weeds can grow at different rates and germinate at different times.
From desert landscape to rolling hills to mountains to rolling plains to river bottom, there are a lot of different climates and temperature variations. Take for instance, the farm fields around Otis and along the Pecos hiway can be much cooler than other areas in town. You can actually feel the temperature change when driving down hiway 285 toward Loving.
Another example would be the neighborhoods that go along the Pecos River through town. Along the water, the climate is actually warmer. Areas along North Shore Drive and neighborhoods like along Doepp Drive are actually warmer due to the water and have a little later germinating period.
Trying to follow guidelines such as when the Forsythias bloom, when the soil temperature is right, or in March or September may be right for some weeds but not for the specific weed you want to control. And in our temperate climate where the growing season is extended, three or more applications a year may be necessary for some weeds and stickers such as Sand Bur and Puncture Vine. Late germination can give just enough time for a plant to go through a short life cycle and produce seed for next year. Plants can be very adaptive to survive.
Weed Identification And Proper Timing
Proper timing depends on knowing the type of weed or group of weeds you wish to target. The first step in any pest or weed control is to first identify the pest or weed.
In most cases, you'll be dealing with the most common broadleaf weeds that grow in Carlsbad and then there are a few weeds that require special herbicides and attention.
Identifying the type of plant will help you understand its life cycle. Knowing if the plant is a Winter annual, a Summer annual, a perennial, etc., will tell you when the plant makes seed, germinates, flowers, and dies. Use this resource, problem weeds of New Mexico, to identify your target plant and find out its life cycle and when is the best time of year to target it.
Winter annuals such as Henbit make seed at the end of their life cycle in late Spring or early Summer and then will germinate in Fall or Winter and grow through Spring until it gets warm. Summer annuals like puncture vine or sand bur make seed in late Summer, germinate in early spring and grow through the summer.
Pre Emergent Herbicides
Most pre emergents used at the suggested application rate will generally be effective for three to five months. This often depends on the type of pre emergent, soil type, and the amount of rainfall and irrigation that the treated area receives.
So if you're targeting puncture vine or sand bur for example, a March application alone generally isn't enough. For these plants, a split application in mid March and May and another in August will generally keep them suppressed. For more information about split applications and Pre-M use see Lawn Weed Control In Southeast New Mexico.
How long the herbicide lasts in the soil will also be affected by the type of soil and how much organic material is in the soil. Soils with little organics and sandy soils will leech the herbicide out quicker than soils with a lot of organic materials in them.
Most common pre emergents used on Carlsbad lawns don't actually kill seeds. The seeds do actually sprout and then the herbicides disrupt the cell division of the newly sprouted plant causing it to die. This is why pre emergents must be watered into the first half inch of the soil shortly after application. If not watered into the first half inch of soil where germination takes place the herbicide will be ineffective.
Spray Treatment Timing
In the Carlsbad, Artesia, and Southeast New Mexico area there are quite a few residents and businesses who have applications done in December and January to target cool weather plants such as Mustard. This is when these weeds really start to show and can quickly take over a property. While most of these will die out when the weather warms, it can still be a battle to try and keep them mowed down until that happens.
Perennial weeds such as Dandelion grow year round in the Southeast New Mexico area. You'll even find them healthy and surviving under freezing snow. Targeting them specifically in Winter, again, isn't necessarily the best time.
Our clients who have a late Fall spray application generally don't have to worry about these Winter and early Spring weeds. The pre emergent we use keeps most of them suppressed. From a consumer standpoint, this is a much better value since the next necessary spray application will be moved up and take care of warmer weather sprouting weeds later into the season. And with this schedule, most of our clients don't generally as many applications in a season.
Generally, a post emergent herbicide, one that kills existing weeds, is applied at the same time as pre emergents in order to kill existing weeds. It's the opinion of many pest control operators that because of this and the heat restricted nature of post emergents, that pre emergents MUST be applied before the end of January in Southeast New Mexico. However, because of new developments, there are herbicides that are not heat restricted and can be applied throughout even the hottest months as long as plants aren't under heat or drought stress.
As well, pre emergents can also be applied without broadleaf killer. So again, in order to get the most for your money and control as many weeds as possible -
- - First identify the weed
- - Understand its life cycle to know the best time for application
- - Determine the best herbicide to use.
Professional Weed Control Service
Whether you would like our services or just need pointers on how you can do it yourself more effectively, give us a call at 575-725-9331. At Horizon Pest And Weed Control Service, we're very knowledgeable about the weeds, grasses, and stickers that infest Carlsbad, Artesia, and Southeast New Mexico yards and properties. And we know what pre emergents and herbicides it takes to control them. We're at your service.