Harvesting Seeds: How to Collect, Prepare and Store seeds for next season.
By: Joanne Curley
Grayson County Master Gardener Intern
Are you enjoying your flowers so much and thinking about how you can grow them again next year? At the end of summer and beginning of fall, many plants are nearing the end of their season. Before cutting back or taking out plants, you may want to consider harvesting some of the seeds for next season. Of course, you don’t have to wait until fall to do this, but fall is a prime time to consider this. Garden flowers and wildflowers are easiest to identify when flowering, so make note of these plants and/or even mark them so you know which ones you’d like to gather seeds from. If the flowers are not on your land, be sure you have the landowner’s permission prior to harvesting or making any adjustments to the plant or location. Other areas that might be considered for collecting seeds for wildflowers might be areas that are going to be developed or destroyed in the near future.
Once you’ve decided that you are going to give seed harvesting a try and have decided what flowers, you want to gather your tools and monitor the flowers. When the flowers look dead, the seeds will turn dark brown or black. Ideally you will want to wait another day or two to the point when the seeds fall out when barely touched. Seeds that are green or not ready will likely fail to germinate next season or they may produce an unhealthy seedling that may or may not survive. It can take experience to know when is the best time, so be patient with yourself. If you are uncertain if it is ready, it may be best to monitor and wait a day or two. When the seed heads are ready, you can simply snip the whole seed head and put it in your paper bag. Seeds should be collected in paper bags, not plastic, since you want them to dry out and plastic baggies will hold the moisture in. You can also lay the seeds out on dry cloths, paper or paper towels for a few days to dry out. Make sure you spread them out and have a very thin layer so they dry.
When you are confident they are dried out completely, you can store the seeds in envelopes that you have labeled, or brown paper bags. It is a good idea to label the plant name, color and date seeds were collected on your bag or envelope. Storing seeds in plastic or airtight containers can encourage mold growth and can damage the seeds, so it is not recommended. It is recommended to store the seeds in a cool, dark, dry place. I usually store mine in the pantry and that has worked fine for me. Note-it is not recommended to store seeds in the freezer as the humidity and moisture level will be too high and can damage your seeds. According to the Lady Bird Johnson Wildflower Center, “The two most critical necessities for storing seeds are constant temperatures and low humidity. A temperature of 50 degrees Fahrenheit or less and a humidity of 50 percent or lower are ideal.”
Tools you will need to harvest your seeds are minimal. Gloves and pruning sheers, brown bags and a pen to label, as well as cloth, screens or paper to lay the seeds out on to dry. Many seeds can be stripped by hand and you will simply use gloves, not needing your pruning sheers.
Ideally, seeds should be planted within a year of collecting them. So, go ahead and give it a try; you have nothing to lose! Next season, you may be enjoying the beauty of having a variety of flowers in your garden and pride in seeing the flowers you worked to harvest and collect seeds for.
Source: Lady Bird Johnson Wildflower Center, Center Staff, 2021. Lady Bird
Grayson County Master Gardeners Association is a non-profit 501(c)(3) organization sponsored by the Texas A&M AgriLife Extension Service. Reach us by email at firstname.lastname@example.org, by phone 903-813-4204, our web page https://txmg.org/grayson/, or our Facebook group.