Preparing Local Prairie Seeds for Winter Planting

Today’s guest post is by Dave Bendlin, from the Rock County Conservationists. He helped organize the December prairie burn with the City, and led the seed spreading crew the following weekend. Here, he explains how seed are selected and prepared…

This area of Big Hill Park was chosen for the overseeding effort because of its visibility to park visitors and its close proximity to the Welty Environmental Center. The area currently has a pretty good stand of prairie grasses, but very few prairie wildflowers. By doing the overseeding, the goal was to create a showy, colorful planted prairie that would be a visual delight to visitors and provide lots of habitat for different pollinators.

 The estimated retail value of the seeds we spread at Big Hill Park was $2760. This was calculated by weighing the seeds for each species collected and looking up the $ value for those weights in the online catalogs of Prairie Moon Nursery and Agrecol Native Plant Nursery. This is why I try to stress to our members who are interested in planting a prairie how much money they can save by participating in our annual prairie seed collecting programs in October of each year.

Most of the seed was collected from planted prairies and remnants at several different locations in Milton, Janesville and Beloit. All of the seed was collected within Rock county except for the purchased Wild Lupine and the Tall Cinquefoil; that came from Jefferson county.  I spent much of my free time in the month of October collecting the seeds. Each species was collected separately, labeled, and stored temporarily in paper bags in an unheated shed to allow them to dry out before processing.

The seeds used for Big Hill Prairie, collected from prairie remnants around Rock County, were meticulously cleaned and sorted. Planting seeds during the winter assures a hard frost that promotes germination.

After the seed collecting was done, I began processing the seed heads to release their seeds so they could be better dispersed for the planting. This processing took up most of my free time in November. (Note to anyone attempting to replicate the processes described below–almost all of these methods generate large amounts of fine dust. You’ll want to wear a dust mask and not do most of this in the house.)

For some species with very small seeds, the seed heads were placed in a 3 gallon pail with a tight fitting lid and given a couple of minutes of vigorous shaking to release the seeds. Then the mixture was sifted through fine mesh fishnets to let the seeds pass through, but hold back any stems or other chaff. This method was used with the Hoary Vervain, Cream Gentian, Bergamot, Blackeyed Susan, Evening Primrose, Mountain Mint and others. This worked very well, resulting in pure, clean seeds with absolutely no chaff left in the final sifting.

To break open the larger seed heads, (Pale Purple Coneflower, White Wild Indigo, Rattlesnake Master, etc.) I used a simple frame of 2X4s covered with three layers of hardware cloth stapled across the bottom. I attached short sides of thin plywood to change the frame into an open box with the screening at the bottom. I would dump the seed heads or pods into the box and crush them with a heavy tamping tool that I have for landscaping purposes. As the seed heads or pods are crushed, their seeds are released and fall through the screening, landing on a clean cement floor in my garage. Then the box frame was lifted up and the seeds were scooped up off the floor with a dustpan and put into labeled plastic bags. 

For smaller seedpods or fruits unsuited to the above methods, hand cleaning was used. The pods of Butterfly Milkweed, seed heads of Culvers Root and the fruits of Wild Rose were all cleaned by painstakingly stripping the seeds out. This was done indoors while sitting at the dining room table watching tv or listening to music, a relaxing way to spend the evening.

Results of the seed spreading are slow to be seen. It will take at least 2 years before any of the plants begin flowering. Most prairie plants spend their first few years on root growth with only small crowns of leaves above ground. The deep root systems of prairie plants are what makes them drought-tolerant and long-lived. The best results won’t be seen until 4 years after the spreading, but after that, the display of flowers will get better each year.

[Do you want to see prairie natives in your garden this spring? Pre-order from the RCC’s Spring Wildflower Sale and save yourself four years!-bkp]