Weed Control Is Essential For Native Plant Establishment and Survival

Let's get right to the point. To ensure the survival of your native plants, you need pre-planting and post-planting weed maintenance. You can't just plant and walk away. However, it is such a common practice, that I talk to someone nearly every week whose seeds didn't germinate or whose young trees and wildflowers were smothered.  

Do any of the following scenarios sound familiar?

1.     You’ve just planted a few hundred trees (or a few thousand in some cases), and it’s time to move on to the next project. A new forest is on its way, and nature will now take over.

2.     You just installed half an acre or 2 acres or maybe even 50 acres of native grasses and wildflowers, and you’re looking forward to nature and all those native plants taking control.

3.     You’ve been working hard for weeks on your home landscape. Native shrubs are in the ground and wildflower seeds have been spread everywhere. You did your part, and it’s time to stand back and let nature do the rest.

That’s what nature does, right? When you install native plants, they take over, wildlife abounds, and they send invasive plants running for the hills. However, a few weeks or a few months later, you’re looking at all that hard work covered in weeds. At some point, everyone from home gardeners, professional landscapers and environmental companies makes the mistake to NOT plan for weeds.

Many home landscape and large habitat projects have failed because of a lack of weed control. Yes, there are occasions where seed mixes, top soil and mulches contain weed seeds, but there’s often an equal and usually greater weed presence already on site.   

For the experienced professional, there’s often a plan for weed control before planting (competition control) and after planting (establishment maintenance). However, the homeowner or landowner trying something such as planting native seeds or trees for the first time can cause themselves extra expense. In some cases, a bad experience will convince them that this and future projects are more trouble than they’re worth.

Unfortunately, we regularly read and hear that if you put native plants back in the landscape, they’ll thrive or outcompete invasive plants. However, for native plants to thrive, assuming they’re planted in the proper place and the proper way to begin with, they usually require a significant amount of weed control well before and well after planting. This is especially true if you’re planting in areas with invasive plants which are practically everywhere. The reality is that native plants are not tougher than non-native plants. In fact, non-native invasive plants are usually the toughest things on the landscape.

  Johnsongrass, a very aggressive invasive plant, dominates this field-woodland edge which is full of recently planted native trees. Johnsongrass grows densely and will quickly reach several feet tall to smother the trees. Most of these trees will die if the Johnsongrass isn’t controlled.   Image by Jody Thompson

Johnsongrass, a very aggressive invasive plant, dominates this field-woodland edge which is full of recently planted native trees. Johnsongrass grows densely and will quickly reach several feet tall to smother the trees. Most of these trees will die if the Johnsongrass isn’t controlled. Image by Jody Thompson

Native plants, like most other plants, go through an establishment period, usually in the 1- to 3-year range, before significant aboveground growth starts. The exception being annuals. During this establishment period, the roots are growing into the surrounding soil environment to a point where they can more easily support normal growth of the rest of the plant. This is typical regardless of whether it's a wildflower, grass or tree. We even pause and restart this establishment process with bareroot and B&B (balled and burlapped) trees and shrubs. Digging these plants cuts off many of the roots, and those plants must recover from that. The establishment period is one of the most sensitive times for a plant, which makes reducing weed competition even more important.    

  Lawn area sprayed with herbicide in preparation for native wildflower seeds. The right side of the image shows a clean area with no weeds and exposed soil. The left side of the image has been unmowed since spraying and shows weeds that will prevent seed germination and shade native plants as the weeds grow taller.   Image by Jody Thompson

Lawn area sprayed with herbicide in preparation for native wildflower seeds. The right side of the image shows a clean area with no weeds and exposed soil. The left side of the image has been unmowed since spraying and shows weeds that will prevent seed germination and shade native plants as the weeds grow taller. Image by Jody Thompson

Work doesn’t stop after establishment though. Just like a vegetable garden, established lawn or mature woodland, weeds are always present and always posing a threat. For a time, these established areas usually have a chance for repair and recovery, but they can only take so much. So, just like weeding the vegetable garden or lawn, you must perform periodic maintenance to maintain your native plantings.

  Eastern redbud, a native tree, has become established throughout this planted prairie. In most grassland situations of the Eastern United States, trees and shrubs are a constant threat to this habitat type.   Image by Jody Thompson

Eastern redbud, a native tree, has become established throughout this planted prairie. In most grassland situations of the Eastern United States, trees and shrubs are a constant threat to this habitat type. Image by Jody Thompson

  Most of the green in this picture is bush honeysuckle, an invasive plant that dominates much of this woodland. This woodland didn’t always look like this, but the threat is always present. Plants often begin their spread unnoticed and catch us unaware. Scheduling periodic maintenance is essential to efficiently maintain a large landscape.   Image by Jody Thompson

Most of the green in this picture is bush honeysuckle, an invasive plant that dominates much of this woodland. This woodland didn’t always look like this, but the threat is always present. Plants often begin their spread unnoticed and catch us unaware. Scheduling periodic maintenance is essential to efficiently maintain a large landscape. Image by Jody Thompson

A FEW WEED CONTROL RULES TO LIVE BY

  1. Generally, the shorter the installed plants, the more weed control needed, with the shortest plants being seeds and the tallest being larger trees. Shorter plants are shaded faster.
  2. No method of weed control will give you complete removal of all potential weeds, but well-planned and well-executed methods will provide the control needed to give your plants the best possible beginning.
  3. Most methods require repeated applications to get a site under control regardless of whether you use herbicides. However, herbicides, when used appropriately, often lead to fewer repeated treatments.
  4. Follow-up treatments, even if only occasional, will always be necessary.
  5. Dry sites (e.g. upland, hilly areas) usually have less weed pressure compared to regularly moist sites (e.g. low lying, occasionally flooded).
  6. The smaller a site, the less necessary herbicides become. The larger a site, the more difficult it becomes to manage without herbicides.
  • Very small sites, such as those often seen in home landscapes, don’t need herbicides if you’re willing to put in a little labor. With a well-executed plan, a single person of reasonable health can sometimes improve or install a small native landscape or very small natural area in a matter of months to a couple of years with little to no herbicide use (except in some extreme cases).
  • However, the success of larger sites, usually measured in acres, is dependent on the level of transformation and how quickly you want that to happen. For example, woodlands tens to hundreds of acres in size and infested with invasive plants are usually unmanageable without numerous people using a combination of methods, including herbicides.

Of course, all situations vary, and you can’t assign blanket rules to any site without knowing numerous important details specific to those sites. These points are only meant to be very general guidelines.

If you remember nothing else from this article, remember that too little weed control before and after planting can lead to project failure. There are certainly many things that affect plant growth and long-term health, but one of the most significant is sunlight. Weeds, among other negative effects, will block sunlight which leads to plant death or stunted plants. Weeds also prevent the seeds of native plants from making contact with soil, which is necessary for their germination.

For your next project, make the weeds just as important as the native plants. Create a plan and put all your tasks on a schedule, and you should start having better success.