White wild indigo is in the legume (bean) family and the seed looks like small beans.
If you can select produce at the grocery store, you can collect seeds. After all, what are fruits and vegetables other than tasty seed pods? Ripeness is judged based on color change (from green to tan, brown, or black; berries ripen to blue, red, or purple-black; or from colored to fluffy white) and a change in texture (seed pods dry and harden; berries get plump & firm). If the seed easily comes off the stem, it is ready for harvesting (though some species are never easy). Wild seeds do not ripen at the same time, so often the best way is to watch for the first plants to release their seeds and collect from the remainder.
Mesh bag method. Once all the seeds have ejected, cut the stem, bring the entire bag inside, and spread out on paper.
Field Collection Rules:
•Harvest no more than 50% of any species or colony. For species that are sparse or rare, collect only 10–30% of the population. Annuals & biennials should be collected <10% of the population.
•Try to collect from multiple colonies, to provide genetic diversity.
•Collect in containers that can be easily transported & sealed, if necessary. I usually use ziplocks & paper bags. If you use plastic, be sure to keep it open as much as you can and spread the seeds out on paper ASAP so that they do not mold or overheat – this can happen in minutes if enclosed in plastic on a sunny day. High heat or mold will kill the seed.
•Mark all your seeds with the species, location collected, and if it is a remnant or restored area. You can use the little paper forms I have or write it on the bag.
•Some species loose viability quickly, even with proper drying. I typically dry these species very briefly – just enough so that condensation isn’t forming inside the plastic – and then store in the refrigerator. Some of these dramatically lose viability in a day, others can be stored this way for weeks. Please get them to CFC ASAP. This includes seeds harvested June or earlier, some sedges, and phlox.
•Bring your collected seeds to CFC, to be dried, cleaned, and stored.
•Illinois Nature Preserves are protected from seed collection & introduction without the proper paperwork and background research. Same goes for threatened & endangered species. Many of the Steward sites fall into these categories, so be sure to review the rules here: http://dnr.state.il.us/INPC/VMG/Illinois%20Plant%20Translocation%20Policy.pdf The goal is to be especially conservative with these areas – do not collect in drought years, do not collect more than 3 years in a row, do not introduce anything unless you are certain that it is local genotype, etc. When in doubt, ask staff or do not collect.
Some tips for tricky seeds:
•Timing is everything. Some seeds ripen very quickly, so try to monitor them regularly.
• Hard to find seeds: If you are working with uncommon, tough to find seeds, mark the plants while still in flower with brightly colored ribbon, marking tape, or place a tall stake nearby. Be sure to choose areas away from the public – you don’t want people taking the seeds or trampling the area to see what’s so special.
• Fluffy seeds: these have a tendency to blow away, especially with strong weather. Try to collect when you first see them fluffing up. Many species can be collected when they just start to turn white, but have not fully expanded.
• Ballistic seeds: this includes species like wild geranium, wild petunia, phlox, and violet. When you see the petals drop, you can cover the flower head with mesh & tie around the stem, forming a little bag. The seed will explode into your bag when ripe and you can collect at your leisure. These species will also ripen in a brown bag, if you harvest them slightly early – watch for the pod to start to turn color. Make sure you close your bag – these seeds will fling themselves 10+ feet away – and enjoy the “popcorn popping” sound.
•Falling seeds: some will quickly drop off the stem. Treat them like fluffy seeds – collect promptly or use a bag to contain them.
• Early collection: it is ALWAYS best to collect seeds at their peak ripeness, but if you do not think you will be back at that time, many species can be collected a little bit early. Think of these like on-the-vine tomatoes or peaches: collect the seeds with a several inches of stem attached and place them in brown bags to ripen.
Guides for identifying seeds
Of course the best way to learn is to obsessively track the changes in your plants or follow around someone who is already familiar with them. But in lieu of that…
Restoring the Tallgrass Prairie: An Illustrated Manual for Iowa and the Upper Midwest by Shirley Shirley (No, that is not a typo). I like this book because the drawings show the entire plant, seed pods, and seeds. Other than the internet, this is the only source I have that shows what seeds look like. The notes have helpful descriptions of what ripe seeds look like and their size – did you know there are 500,000 lobelia seeds per ounce? You might mistake the seeds for dust or bug eggs. Con: this book contains only prairie species.
William Cullina’s books, i.e. Wildflowers: A Guide to Growing and Propagating Native Flowers of North America I first discovered the wildflower book in my public library and quickly invested in several of his books for my personal collection. It has great descriptions of why natives are important, how individual species can work in landscaping, propagation techniques, species lists for different garden types, and also some harvesting tips (check both the species description in the main section & the quick guide in the back). The great photos and engaging narrative make this a coffee table-worthy book. Con: not every species is mentioned in regards to harvesting, and it features New England plants (though many are similar to our natives).
Begin With A Seed spreadsheet This came with my propagation manual from the Riveredge Nature Center in Wisconsin. The spreadsheet contains lots of great information – blooming dates, seed dates, habitats, and other interesting details. I love that this is in spreadsheet form and you can easily sort for a variety of data. Con: the dates are for central Wisconsin, so look earlier than noted. Only prairie & savanna species are included.
Nature Conservancy data This is a wonderful collection of data, similar to the Begin With A Seed information, but with Illinois data. Con: I only have a copy of this, so you will have to stop by my office to see it. I hope to digitize it into a spreadsheet, but I don’t know when I will have the time to do so.
Prairie Moon Nursery catalog (free download www.prairiemoon.com) This nursery provides a wealth of information about the habitats, germination treatments, seed weights, and prices. Most of their species are pictured online, including pictures of the cleaned seed.
Written by Kelly Schultz 4–12