The tallgrass prairie once dominated Iowa prior to European settlement and is the reason we have some of the richest soils in the world. A prairie ecosystem provides many services including reduced soil erosion, increased water infiltration, and deep living root systems to circulate nutrients and build soil organic matter. Above ground a diverse array of cool and warm season grasses and forbs (flowers) provides wildlife and pollinator habitat throughout the year.
This year in Allamakee County over 1,925 acres were enrolled in the Conservation Reserve Program (CRP) with over 1,640 of those acres seeded to native prairie. Although an established prairie plant community is low maintenance, it is not maintenance-free. Careful attention is required especially in the first one to three years to ensure a successful stand. With 560 more acres slated to be seeded in spring 2017, it is a good time to touch on the importance of proper maintenance required during the establishment years.
As with any new seeding, whether it be introduced species or natives, keeping the weeds under control is crucial while your seedlings are getting established. With native plants, patience is key. During the first two years these plants are putting all their energy into growing deep root systems and may not display much growth above ground. It is important to reduce any weed competition for sunlight by mowing at least 3 times during the growing season. Duration and frequency of mowing will depend on weed pressure. A good rule of thumb is to mow the weeds when they are calf high to a height of 5”-8”. Cutting height should be raised as seedlings grow. It is important not to let the weeds get above knee high. Mowing weeds at this height with a rotary mower could smother young seedlings. Mowing often will also prevent weeds from going to seed. The second growing season usually only requires mowing twice depending on the density of weeds.
As a reminder, during the initial two years of establishment mowing can be completed at any time during the growing season. After you receive a final status review from NRCS it is required to get permission from FSA to spot mow during the primary nesting season (May 15-Aug 1). Outside of those dates spot mowing for weed or tree control is permitted.
Article by Megan Waechter, NRCS Soil Conservationist