Site Preparation
A restoration project is only as good as its beginning.
Here’s what you need to know.
Site Evaluation
Before a restoration program of any kind can get started, a thorough site evaluation is necessary. Ideally, the site evaluation occurs before the project is designed but it is always a good idea to re-evaluate the existing vegetation prior to commencing work. Here’s why.
There are good weeds, bad weeds, and terrible weeds. The good weeds are usually native annuals and biennials that pop-up soon after a project starts. They aren’t necessarily the plants that you want but they are an important part of a site’s recovery. Bad weeds are those that you definitely do not want because they detract from what you are trying to accomplish. Bad weeds are mostly a nuisance and tend to get worked out of a restoration project if everything else goes well. Terrible weeds are those that actively work against you and that can reverse all your hard work. These are mostly invasives such as multiflora rose, olives, pears, knotweed, hops, and many more.
Knowing the difference between your weeds informs how to tackel them as you begin your project.
Weed and Invasive Suppression
Suppressing weeds and treating invasives is often the very first act of performing any type of restoration project.
The techniques employed vary with the specie being managed and the availble treatment dates.
Treatment methods can somtimes involve mechanical techiques such as cutting, mowing, discing, and tilling. But many bad weeds and most terrible weeds act as if they are immune to mechanical control.
Chemicals are employed by most professional restoration firms because their use is often the most efficacious and the only affordable method. When properly prescribed and applied, chemicals are able to replace the work of 1000s of hours of manual labor and cause less damage to the soil, to desirable plant species, and wildlife in general.
Visit the US Forest Service website to learn more about invasives and their control techniques.
Pasture and Turf Suppression
Turf grass and pasture grasses have been bred and selected for their vigor and resilience for hundreds of years. They quickly spread to disturbed areas and can effectively choke out weeds. These desirable characteristics are essential qualities for actively used open spaces in parks and for raising livestock, respectively.
But it is these same characteristics that necessitate their complete removal from a restoration project. Most turf grass and pasture grasses are capable of quickly recovering from anything less than an aggressive suppression program, which can take up to three years to complete. A particularly troublesome species is reed canary grass, which was initially promoted as useful for forage and for erosion control purposes. Today, it is a virulent invasive species that infests streambanks, wet meadows, and riparian areas making them unsuitable for unavailable for wildlife.
Vehicular-mounted sprayers are common initially, with backpacks used for follow-up treatments.
One important learning from our projects is resisting the urge to move forward before all grasses are removed.
When is it Safe to Proceed?
The easy answer is, “when there are no more invasives, turf, or pasture grasses remaining” but this is easier said than done.
Remnants of controlled weeds can always remain as the result of a missed spot, or excessive thatch, or the chemical tank running out before it was noticed. The only reliable method of determining the success of the suppression is to wait for for spring to arrive, or at least the fall. Cooler temperatures and increased rainfall encourage all plants to grow, including your target species. If your site shows few signs of invasives, turf, and pasture grasses after the waiting period, you can prepare the site for seeding.
Use a site-suitable device to lightly disturb the surface of the soil to prepare it for seed. If possible, wait for a gentle rain and some 80deg temperatures to see if any invasives, turf, or pasture grasses re-emerge.
Seeding for Future Success
Planting seeds following a weed or invasive control regimen is a requirement in most jurisdictions to help prevent the loss of soil during a large rain event.
There are many approaches to seeding and choosing the the practice that best matches your intended restoration goals is crucial for avoiding unecessary future expenses and delays.
The minimum practice is seeding with an annual cereal or short-lived grass such as annual rye. The maximum practice is spending a large sum on an expensive perennial wildflower seed mix. But there are better options to these.
The ideal seeding practice is the three-pass method wherein species are introduced to the site in phases based on the site’s response to prior activities. Species are planted based on the site’s readiness to receive those species, with sensitive or conservation-grade species generally being the last to be installed.
Evaluating a Seeding Event
Seeding performance is difficult to ascertain for the first few years without employing an ecologist or botanist to survey seedlings.
Most restoration practitioners will add a temporary marker species into the seed mix to make it easier to at least evaluate the coverage of the seeding event. Black-eyed Susan or non-native annuals are popular choices.
More important is evaluating the proportions of good, bad, and terrible weeds. Good weeds should show up early and in at least the same abundance as the marker species. Bad weeds should be less than 10% of the seeded area and terrible weeds should not be present at all.
Communicate with your ArcheWild project manager, or your contractor, about any observations or concerns after a seeding event.
You should be able to observe most of the intentional species in Year 3 but you’ll have to wait until Year 7 to decide if the seeding performed as expected.
What to do if you still have Weeds
Continuous monitoring and maintenance of a seeded area, whether it be an old pasture or a reforestation, is essential to the seeding having its desired effect.
You can sometimes rely on your seeding contractor to perform this monitoring and maintenance service; if not, ArcheWild staff can perform these functions.
While the goal of the preparation stage is to remove all problematic and competitive vegetation, 100% control is rarely achieved. Be prepared to continue managing your seeded areas for up to three years after seeding. Year 4 is often the turning point wherein your seeded area will be able to continue on its own unaided, or revert back to weeds or invasives.
It makes little sense to skimp on monitoring and maintenance lest you lose any previous investment.
