Now That the Plants Are In, Maintain to Sustain
Following through with upkeep after a restoration landscape is installed easy to overlook. It takes just a few months for a typical, large-scale landscape planting plan to deteriorate without adequate maintenance. Luckily, a vegetative mitigation planting for a disturbed stream buffer is not the same as an ornamental landscape. It requires a less-intensive maintenance approach.
Start with a site where invasive plants have been eradicated before planting. It is best to remove exotic pest plants in adjacent areas, too. Then go with a reliable, self-sustainable landscape design that requires minimal care once the plants are in the ground. Cover the ground with natives—grasses, herbaceous forbs, and seedlings to get the upper hand on the non-native competition. A good design and proper installation can save you lots of trouble later. Understanding natural plant succession can ease long-term maintenance by creating a stream buffer site that grows spontaneously into a typical, unmanaged woods.
A multitrophic stream buffer planting starts small. The ground surface starts as an inexpensive seed mix and the tree and shrub seedlings are usually only three feet tall. These items act as placeholders for the eventual volunteer growth that makes up a mature woodland buffer. They need to grow vigorously and remain healthy until the real buffer vegetation fills the site. Do the following two things to provide the best chance of success: 1. Seed with a mix of quick-cover native grasses and herbaceous forbs adapted to both cool and warm-season germination to stabilize the disturbed soil. 2. Plant bare root seedlings rather than container plant material during the dormant season to ensure immediate, full root contact with moist soils.
That’s not enough to guarantee a thriving wetland, though.
Newly-vegetated sites need to be kept invasive-free, and there is no surety the site will remain consistently moist enough to germinate the seeds and keep the seedlings alive until deep roots are established. The only motivation for essential maintenance of the site will come through contractual requirements in a maintenance work plan agreement with the installation contractor. For public rights-of-way, road crews give the land beyond the pavement low priority. Holding the plant installation contractor to responsibilities that guarantee vegetation establishment and viability for several years is vital to the success of the project.
Your planting specifications should hold the contractor to at least two full growing seasons of maintenance responsibility. By then, the ground should be thick with growth and the seedlings should have tapped into their own water source. Periodic evaluations with multiple inspections and plenty of time for replanting lost seedlings should be written into the specifications. A single evaluation before closing out the contract will be too little, too late.
Two fall inspections, one after each of the two growing seasons, should suffice. Then, if non-viable plant material is discovered, the contractor can replace plants the following dormant season. Invasive plant material needs can be addressed on a regular basis, and the inspections are a good time to point out problem areas. Final payment can be scheduled after the third spring, with necessary amounts withheld for any final replacement costs. By doing this, planting might begin late in year one, with the first inspection in year two, the second inspection in year three, and final payment in late spring of year four.
An adequate restoration plant establishment period has significant consequences for the main project construction calendar. Accounting for the time requires a special provision for prosecution and progress deadlines, so planting isn’t left until the last moment. Even if closing of the contract is delayed, it is advantageous to extend the maintenance responsibilities of the contractor to the full time needed for viable plant growth and the start of successful natural succession. Establishing a formal schedule for inspections, replanting, and final inspection allows for suitable enforcement of contract specifications.
Put it in writing, and make it part of the contract. Incorporating maintenance requirements and scheduled inspection deadlines into contract specifications is the only way to ensure realization of proper planting restoration for disturbed stream buffers. These baby landscapes need nurturing to grow and take care of themselves. You can give them that by building dormant installation, maintenance, and plant replacement time into the project calendar.
You Can Read More About wetland stream restoration planting in the new Advanced Guide to Environmental Mitigation Planting eBook, based on years of experience working with the pros and providing guidance for the most efficient and cost-effective way to plant stream relocation, storm water retention, and wetland projects.