Restoration Techniques: Seed Collecting and Planting

 

One of the most important aspects of prairie and savanna restoration is planting native species that once were present in the ecosystem. All degraded habitats will have lost species, frequently many kinds, usually from grazing or from encroachment by invading brush.

As part of the prairie and oak savanna restoration work we are carrying out at Pleasant Valley Conservancy, we have been reseeding areas that have been cleared of undesirable vegetation. Species planted are only natives that were present elsewhere on the Conservancy, or are present in nearby natural areas. Seeding is an on-going activity, which we have been carrying out annually for over 10 years.

At Pleasant Valley Conservancy, remnant prairies, such as those of the south-facing slope, had some prairie species present, but others had been lost, probably because the slope was grazed. Savanna remnants were more degraded, since brush invasion was well advanced.

Seeds were collected from other parts of the Conservancy, or from nearby sites such as roadsides. For some species, seeds were brought in from more distant locations, but always from southern Wisconsin sites. The point here was to use "local genotypes".

Seeds can be planted either in the spring or fall. Fall planting is ideal, since the seeds then overwinter under conditions that mimic those in nature. However, it is essential that planted seeds reach bare ground, which usually means after a burn. Although fall burning is often excellent, it depends upon favorable weather conditions, and may be thwarted by an early winter.

If planting must be delayed until spring, then the seeds must be stored in the cold, generally outdoors in a protected location. At Pleasant Valley Conservancy, we store our seeds in feed bags which are hung in the barn (to protect them from rodents). As soon as spring burns are finished, the seeds are planted. Early spring burns are ideal, but again, weather may prevent this.

Quality of seed plays a major role in the success of a planting operation. Seed viability can vary markedly from year to year, depending on the weather during the period of flowering and seed setting. Seed purchased from commercial sources has the advantage here, because it is sold on a Pure Live Seed (PLS) basis. Purchased seed has two major drawbacks: it is expensive; and it is probably not a local genotype.

The variable quality of seed is one reason that locations should be planted more than once. For certain of our restoration units at Pleasant Valley, we have planted four or five times, sometimes even more. Each year is different, so some species may become established one year and not another.

Seed collecting is an excellent volunteer activity. It occurs during a pleasant period of time in the early fall, is relatively easy to do, and makes an important contribution to the restoration process.

 

 

Because of the importance of having good seed, careful attention must be been paid to seed collecting times and techniques. The tables give approximate seed collecting dates for southern Wisconsin.

Planting

Planting can be done by hand or by mechanical means such as drill planters or seed spreaders. All of the planting at Pleasant Valley Conservancy has been by hand.

An important planting consideration is the seeding rate (number of live seeds per unit area). The best source of information is the publication by Richard Henderson, Plant Species Composition of Wisconsin Prairies, which is Technical Bulletin No. 188 of the Wisconsin Department of Natural Resources. Although this publication is out of print, an on-line version is available through the University of Wisconsin-Madison Digital Collections. The URL is http://digital.library.wisc.edu/1711.dl/EcoNatRes.DNRBull188

Seeding rates are based on Pure Live Seed (PLS) per acre. The PLS value is obtained from germination tests, or from the vendor of the seeds. Acreage is best measured these days with a global positioning system (GPS) device.

Seeds for planting are mixed with sawdust as a carrier. This helps to maintain the small-seeded species in suspension and to aid in distributing the seed. Buckets are the preferred carrier for the seeds, although paper bags can be used when only small areas are being planted.

The area to be planted is divided into subunits such as half- or quarter-acre amounts. Each subunit is marked with flags or cones and the requisite number of buckets distributed.

Again, planting is an excellent volunteer activity, and is generally considered enjoyable. Each volunteer is given a subunit to plant, and instructed to distribute the seed as uniformly as possible over the area. For large acreages, the promise of refreshments or lunch after the event will usually help to bring out a large cadre of volunteers.

 

Fall planting. Distributing seed mixes into buckets for planting an oak avanna.