Beginning late spring, seed collection became a priority for the restoration crew at Shaw. Earlier this year, there was a meeting between the horticulture and restoration staff and the seed bank manager where a list of species to collect for the IMLS Woods was determined.
Collecting, processing, and sowing native seed is an essential part of restoration. Both removing invasives and sowing seed need to happen together. Once invasive plants are removed in an area, if we don’t help the native plants establish quickly, the undesired plants will find their way back and continue to dominate. Depending on the area being restored, the species list will vary. An upland woodland seed mix would be different from a wetland or a glade because different plants thrive in each type of ecosystem.
We currently spend about half of our time spraying invasives and the other half collecting seed. The first step in seed collection is knowing where large populations of a species are. Luckily for us, there are staff who have worked at Shaw for over 20 years and know exactly where most of the plants are. I also try to mentally note where certain plants are when they are flowering so we can go back and collect later. It’s much harder to find them when they’re no longer blooming.
Once we’ve located the seed, we wait until they’re mature. We reference a spreadsheet created from past years’ experience that contains the range of dates each species was collected in. This gives us an idea of when to start checking for ripeness, though the timing is still greatly influenced by the weather conditions of that year. For example, we had a very early spring this year (it was 70°F in February!) which resulted in atypical and unpredictable phenology of many species. We can visually assess whether a seed is ready to collect. Mature seeds are brown or black, hard, and sometimes shiny, as opposed to white or green and soft. We look for seed heads or stems that are dry and turning straw-colored as well as seed pods that have opened on their own. If the seeds fall off with a light shake or touch, they are ready! Not all seeds in one population or even on one plant will be ripe at the same time. Most of the time, seeds can after-ripen, which means they will mature on the drying rack, so we aren’t too worried about snipping off stems that contain some unready seeds. It’s a good time to collect when most of the seeds are mature and some have fallen off on their own.
We collect seeds by stripping them off with our hands; this method works well with most grasses. We also cut off seed heads with scissors. The seed is placed in bags that we strap to our waists or buckets. At the end of the day, we lay the seed in open cardboard boxes or tarps in the hanger, where they are stored temporarily.
Once dry, we process the seed. For restoration, the main goal is to make sure the seeds are no longer concentrated in the seed head or pod. When we mix the seed for sowing, we want them to be individual seeds so that we don’t end up with clumps of one species in one area. For our purposes, it is not necessary to clean them so that there is no plant material besides seed. But because we have limited storage space, we try to sift out some of the chaff (stems, pods, other non-seed plant material) to reduce the volume of each species. Depending on the quantity, shape, and size of the seed, we either hand clean or hammer mill them. Hand cleaning involves putting the seed through one or several sieves to remove the larger plant debris. We mill seed when we have a large amount or when there is a lot of extra plant material. The resulting pile of chopped up stem and seed is then sifted.
The last step is to label, weigh, and store the seed. We have bins in the seed closet dedicated to the IMLS Woods restoration. The seed is now ready to be mixed and sowed this winter!
With less than a month left in my placement, I am already sad about leaving. Though the heat, humidity, and bugs have been a challenge, most days I still can’t believe that my job is to work outside in these beautiful natural areas. I have learned so much in the past few months while having a great time. It’s incredible how my knowledge of the restoration process has increased along with the skills and hands-on experience I have gained. Sometimes I’m overwhelmed by how much I still don’t know, but I’m so excited to continue learning and working in this field. I would like to thank Mike Saxton, Quinn Long, and the entire SNR staff for such a great placement. I look forward to applying my new skills and knowledge to future jobs!