Your CBD Hemp crop may ‘grow like a weed’ but that doesn’t mean you want ‘weeds’ in your hemp crop! Smart CBD hemp farmers implement a weed-control strategy, just like farmers do for any other commercially-grown agricultural crop.
Nothing is worse than watching all the hard work of the spring, planting out your hemp seeds and then watching your promising young plants overwhelming by a weed outbreak.
An unmanaged weed problem in a hemp crop can lead to many problems:
- High labor costs for weed control
- Reduced CBD yields and flower quality
- Increased disease and pest pressure
- Mold and mildew outbreaks at harvest time
- A rank, messy field at harvest time increasing harvest expenses
The best strategy to controlling weeds on your CBD hemp farm is to have a plan in place before you plant out your transplants. Then ruthlessly follow your plan through the season. Weeds get a foothold when farmers are busy taking care of other tasks or weren’t properly prepared for the mid-summer weed explosion.
The experienced hemp growers at Colorado Breeders Depot compiled this list of weed-control strategies to consider implementing on your hemp farm.
7 Ways to Control Weeds in Your CBD Hemp Crop
Start Clean for a Weed-Free Hemp Crop
Don’t plant into a field with a history of perennial weeds, like thistle or quack grass, or was recently converted out of pasture. The same is true for fields with high annual weed pressure that was allowed to go to seed (all those weed seeds mean even MORE weeds the next year).Your hemp field should have been prepped the fall before planting and ideally (depending on your region) planted to a cover crop. Then the field is tilled in, prepped and young transplants are placed into a field with no vegetation growing (unless you are planting following a no-till strategy, see below).
Plant Your Hemp Transplants at the Right Time
Waiting to plant out your hemp transplants when the weather is ideal for their growth means they will thrive and (hopefully) outcompete the weeds.Hemp plants do grow big, quite rapidly. A well-timed transplanting of healthy, vigorous hemp transplants encourages rapid growth that can (ideally) shade out potential weed seeds from germinating.
Plant into Plastic Mulch
Many experienced CBD hemp growers plant their crop into plastic mulch beds.Plastic mulch (typically black or sometimes green plastic, stretched taught over a planting bed) controls weeds because weed seeds won’t germinate under the plastic. Growers punch a hole through the plastic and plant their young hemp transplants through the plastic.
However, plastic mulch isn’t a perfect solution. Weeds will still grow in the pathways between the edges of the plastic. Growers will need to invest in a plastic mulch layer (although this is a piece of equipment that can be used for many different crops) and drip irrigation must be laid down underneath the plastic.
Another hassle with plastic mulch is removing it and disposing of it at the end of the season.
Spread Natural Mulch Materials
Growers who want the advantages of plastic mulch but don’t want to deal with that much plastic may choose to use natural mulch materials instead — like compost, straw, or another spreadable material that decomposes naturally.A natural mulch does not need to be removed and disposed of at the end of the season and depending on what material is used (like compost, for instance), natural mulches can add valuable nutrients to your field that can be useful for subsequent plantings.
However, there is typically a lot of labor involved in spreading a mulch layer thick enough to suppress weeds from germination. And, you have to have access to enough mulch at an affordable cost. Sometimes mulch encourages diseases and pest outbreaks.
Ironically, mulch can even create a weed problem, if the mulch you use has weed seeds in it (like straw, for example). Make sure to experiment with the effects of different natural mulching materials over a season before going hog-wild with spreading mulch on your hemp crop.
Another strategy many growers employ is cultivating their field as often as possible while the hemp plants are young.Frequent cultivation of a well-prepped, relatively clean field can remove young weed seedlings before they are established. Ideally, by the time the hemp plants are getting so big, you can’t get through the field with equipment. They are also big enough to shade out any more weed seeds that might try to germinate.
Cultivation in larger hemp farms is typically accomplished with cultivating equipment — a tractor pulling a set-up of cultivating discs, shovels, finger-weeders or basket-weeders. Rows must be planned to accommodate equipment, so tractors can be driven over the top (or between) of the hemp plants without harming them. Smaller operations may accomplish the same thing with farm labor and hoes.
Whatever cultivation tools you use will need to be selected for your soil type and weed presence. But the main rule with cultivation (whether mechanically or by hand) is to cultivate often, when the weeds are just germinating. Once you get behind on cultivation it can be almost impossible to catch up with rapid weed growth.
A relatively new strategy for weed control is following a ‘no-till’ method.To create a no-till field, growers first plant a cover crop, either in the fall or spring before they plant their hemp transplants out. Then, typically, the cover crop is rolled or “crimped” down to the ground, laying it flat and killing the growth. Hemp transplants are planted through the natural layer of plant mulch created from the cover crop.
No-till works similar to using plastic mulch or spreading a mulch material, but instead utilizes a living cover crop and growers don’t till up their soil before planting. Some growers believe keeping roots in the ground and avoiding tillage creates better soil health.
No-till techniques can be very advantageous for growers working to build up the organic matter in their soil. However, it is crucial to choose the right cover crop for your region and to get the timing just right. Also, specialized equipment (a roller-crimper and a no-till planter) are usually needed.
Many hemp growers wonder if they can use herbicides (chemical weed killers) on their hemp crop. There are several concerns with that.First of all, there are no currently “approved” herbicides for hemp. An herbicide like glyphosate, for example, cannot be used to kill weeds in pathways between rows of hemp plants. However, growers can use herbicides to kill weeds in a field before planting out their hemp crop.
Another concern with using herbicides is that most CBD or smokable hemp buyers require full lab results showing potential problems like heavy metals or chemicals in the harvest. Because most consumers are smoking or consuming hemp CBD products to support their health, buyers are typically very concerned about any possible chemical pollutants and may pass over buying a crop that shows pollutants in the harvest lab tests.
Choosing the Right Weed Control Strategy for Your Hemp Farm
There are plenty more weed control strategies that hemp growers employ.
Some “mow” down the weeds between their rows. Others plant into tilled strips between cover crops. Some seed fast-growing cover crops in between rows after they plant their transplants. The best weed-control strategy for most farmers often include many different elements of the ideas we have posted above and will take some fine-tuning to dial in. But what is essential is finding a plan that works for your farm, even if it takes a season or two.
Need a hand coming up with the best weed-control strategy for your hemp farm? Don’t hesitate, give Colorado Breeders Depot a call. We’d love to help you out. We’ll help you consider your opportunities, consult on your growing plan and advise you throughout. Helping our customers have an excellent hemp harvest — starting with the seed they plant — is our number one goal.