Collecting Wildflower and Prairie Seed

Description/Purpose:

Prairie plants and wildflowers are finding their way into our landscapes both in gardens and yards, and into restored landscapes. The returned interest towards prairie plants and wildflowers signifies a movement in landscape design towards a more naturalized landscape. Using native species to recreate plant and wildlife communities only makes sense. Restoring and preserving landscapes is important because it helps create and sustain ecosystems and their diverse communities of plants and wildlife.

Finding a diverse source of plant material can be difficult because this is a new trend, and the demand is increasing. Seeds are a natural source of potential plants and collecting them is both economical and easy.

There are potential problems in where they can be collected, and ethical issues when moving plants around in the wild. These issues will be discussed in detail later.

Amounts, Specifications & Supplies:

Every genus and species of plants with seed that is collectable is different and each varies through the season with the environment. Collecting seeds of plants that are easily propagated by seed are the best to start with. Collecting seeds of plants that propagate easier by division or other means is impractical. Plants that grow best from seed include those with long taproots, and other plants that do not easily transplant. Collecting the seed of biennials is also significant because there is the potential of having yearly bloom by seeding every year.

Experience and time are the two factors to consider when collecting seeds. First, observe the plants; watch the life and growth cycle of each species. This is important because it is the best way to find out when plants bloom and when the seeds are ready for collection. Second, compile a record of observations for future seasons and collecting. Together, these two processes will help to overcome the most difficult part of seed collection, timing.

Tools and equipment:

Seed collection of prairie plants and wildflowers is done primarily by hand. This is because most plants to be harvested don't grow in pure stands and the topography varies limiting mechanical equipment use. There is also limited mechanical equipment available. The majority of equipment used is makeshift and site or plant type specific. For example, collecting the seeds of most grasses can be done by stripping the culms (the flowering shoot) off the stem. This can be done by hand or with mechanical fingers of sheet metal.

Basic equipment needed to collect seeds includes gloves, boots, drop cloths, pruning shears, boxes, baskets, and paper or canvas bags (plastic bags will allow the seeds to get moldy more easily). Numerous references cite a good pair of gardening gloves as the best tool. A tray of some kind (like a flat cake pan) can be used to collect the seeds of herbaceous wildflowers.

Various kinds of machinery can be used to clean the seeds after collection. A tumbler that thrashes grass seeds can be used to separate the seeds from other plant parts or a blender can separate fleshy seeds from the pulp. Screens with various size openings are helpful to separate seeds from other plant parts.

Site Considerations:

It is advisable to consider plant conservation ethics when considering the site or collection. Some collectors will only collect seeds from their county or state; some won't mix seeds from two different areas. Others attempt to collect the entire gene pool of the stand in order to preserve the diversity of a species. A few collect rarities regardless of origin or potential distribution, while others would never collect anything rare fearing extinction of the plant. Collectors of rare plants also may be excellent propagators with the mission of helping a rare species survive. Ethical issues are important because of the possible consequences.

Considering where you are collecting from and where you'll be taking those seeds to is important because the last thing you want is to introduce a species that could potentially hybridize with a native and then become invasive like what happened with Lythrum salicaria. In that case, the exotic species pollinated the native species yielding a hybrid that is very invasive in wetland marsh areas.

Conservation groups stress that seeds should not be collected from the wild, and in most states this is illegal. It is also illegal to collect plants from a property without the permission of the owner. Areas where native plants will be destroyed or where future development is set to occur are the best sites for seed collection.

It is advisable to limit the amount of seed taken from any given plant. Taking one third (or less) of the seed ensures that the plant will sustain itself for future enjoyment and harvest.

Step by Step Process:

1. Acquiring Knowledge
Familiarity with the phonology, the life cycle of the plant, you collect seed from is important because it is necessary to know when flowering, seed formation and seed maturity will occur. Understanding dispersal mechanisms of the species and the effects of environmental changes, such as the weather, is also helpful.

2. Observation and Timing Collection
Observing the plants through their life cycle is the next step. Timing of harvest is important because if seeds are collected too early, the seeds will be immature and have low seed viability. If seeds are collected too late, they can dehisce quickly and be lost. Seeds that are collected after dispersal are usually of low quality and are potentially costly to clean. Another potential timing problem is that seeds often do not ripen uniformly over the same flower stalk. Prolonged flowering and different stages of seed maturity limit uniform seed collection. Observation is the best way to determine when seeds should be collected.

Plants that have seeds that ripen in pods should be collected just as the pods are beginning to open. Collecting the entire pod is advisable because this allows the seed to continue ripening in the pod as it dries. Plants that dehisce (break open and dispel seeds) can be contained by placing a paper sack over the seed head and closing the open end with a twist tie. Exposure to light and air will allow seed ripening as the bag collects the seed. This method allows for collection once at the end of seed maturation.
Seeds that are mature are often dark in color, firm and dry. Fleshy seeds often turn color as they mature and become ripe. These seeds should be collected as they are changing color.

When the seed collecting should occur is based primarily on observation; however, other means of determining seed maturity exist.

Using the moisture content of the seeds is possible. Immature seeds have a moisture content of approximately 60%; whereas mature seeds has a moisture content closer to 10%. Seed maturity-moisture content curves have been determined for a number of species and can be used as a guide to collecting seeds. The basic concept of seed maturity increasing as moisture content decreases can be used as helpful guide.
Experimenting with germination tests is also helpful in determining at what stage seeds can be collected.

3. Harvesting Seeds
Method for harvesting seeds depends on the type of plant.

Grass seeds are collected by stripping the flowering culms off the stems. The seeds are inside the inflorescence of the flowering culm. Running your fingers up the stem is usually the easiest way to collect grass seeds. See Figure 1.
Prairie plants and wildflowers that have spiny thistle-like seeds should be collected as an entire seed head. See Figure 2.
Prairie plants and wildflowers with seeds in a spike-like inflorescence (the flowering shoot) can be like grass seed.
Prairie plants and wildflowers with seeds in pods or capsules are easily collected by collecting the entire pod or capsule or by shaking the inflorescence over a tray to catch the seeds. See Figures 3 and 4.
Prairie plants and wildflowers with fleshy seeds should be picked by hand.

4. Drying and Ripening
Allowing the seeds to fully mature and ripen after harvest is important and best done by allowing air to circulate in the collection bags. Labeling the contents of each bag is very important and should be done throughout the collecting process.

5. Threshing
Some threshing or beating of the inflorescence may be necessary before the seeds can be sorted out. The advantages of threshing are that volume is reduced and potential problems like pathogens and insects that could cause damage are reduced. Threshing is easily done by rubbing the inflorescence against a coarse screen (wearing gloves is advised). Other types of threshing include using paddles covered with rubber matting that you rub the inflorescences between, or the mechanical version where hammer-like fingers rotate inside a metal cylinder.

6. Cleaning the Seeds
The next step is cleaning the seeds. The objective of this is to separate the seed from the rest of the plant material. This is most easily done using screens with various size openings. A blender can be used on small fleshy seeds. The seed of some species can be sowed with other plant parts. Additional research and experimentation will determine what is most effective.

7. Seed Storage
The last step is storing the seeds. Information is available on optimal seed storage for specific species. The following guidelines can be used in storing most seeds.

Store seeds in paper bags. This allows air circulation and prevents mold.
Low and constant humidity and temperature (less than 50 degrees Fahrenheit and less than 50% humidity) is ideal.
Using a mild insecticide or fungicide may be advisable if a potential problem is apparent.
Fleshy seeds should be planted as soon as possible and kept moist once clean. If these seeds dry out, they will lose their viability or could possibly germinate. Storing them in a one-to-one ratio of moist sand-sphagnum moss or peat-perlite mixture is the best option.

Sources:

The following is a list of Minnesota Wildflower and Prairie Seed Sources:

Albert Lea Seed House
PO Box 127
Albert Lea, MN 56007

Mark E. Gullickson
RR 2 Box 150A
Fertile, MN 56540
(218) 945-6894

Applied Ecology: Native Landscape Restoration and Management
4316 45th Ave S.
Minneapolis, MN 55406
(612) 724-8916

Kaste Inc.
RR 2 Box 153
Fertilie, MN 56540
(218) 945-6738

Feder's Prairie Seed Co.
12871 380th Ave
Blue Earth, MN 56013-9608
(507) 526-3049
feder@blueearth.polaristel.net

Landscape Alternatives
1705 St. Albans St.
Roseville, MN 55113
(651) 488-3142

Mohn Frontier Seed and Nursery
RR 1 Box 152
Cottonwood, MN 56229
(507) 423-6482

North American Prairies Company
11754 Jarvis Ave
Annandale, MN 55302
(320) 274-5316

Norfarm Seed Company
PO Box 725
Bemidji, MN 56601
(218) 751-3350

Petersen Sales Wildflowers
3557 E. Bregnedalgade St.
Askov, MN 55704
(320) 838-3367

Prairie Moon Nursery
RR 3 Box 163
Winona, MN 55987
(507) 452-1362

Peterson Seed Company, Inc.
7800 E. Highway 101
Shakopee, MN 55704
(612) 445-2606 (Wholesale only)

Prairie Restorations Inc.
PO Box 327
Princeton, MN 55371
(612) 389-4342

Prairie Hill Wildflowers
RR 1Box 191A
Ellendale, MN 56026
(507) 451-7791

Shooting Star Native Seed
RR 2 Box 191
Spring Grove, MN 55974
(507) 498-3993 (Wholesale only)

"The Prairie Is My Garden" Seed Company
13633 Ferman Ave NW
Clearwater, MN 55320
(612) 878-1694

Wildlife Habitat
RR 3 Box 178
Owatonna, MN 55060
(507) 451-6771

Naturally WILD
3539 West 44th Street
Minneapolis, MN 55410
(612) 922-9279

References:

Kyhl, John F., Meyer, Mary H. and Krischik, Vera A. 1997. Establishing and Maintaining a Prairie Garden. University of Minnesota Extension Service FO-7848-C.

National Wildflower Research Center. 1989. "The Wildflower Handbook." Texas Monthly Press, Texas.

Personal Interview with Lisa Larson, Native Plant Propagator at Hennipen Parks Nursery 5/4/98.

Stein, Sarah. "Questions of Collection." The American Gardener. November/December 1996: p24-34.

Sheldon, Elizabeth. "The Fun art of Seed Gathering." American Horticulturalist. October 1989: p24-29.

Young, James A. & Young, Cheryl G. 1986. "Collecting Processing and Germinating Seeds of Wildland Plants." Oregon: Timber Press.

This implementation report was developed by Courtney Tchida, Environmental Horticulture Student.