Virtually all the plants we put in the ground on the natural lands are grown from seed at our McAlpin Farm greenhouses in Seal Harbor. When people learn this, they are often curious about where we get our seeds. While we sometimes purchase hard-to-find seeds, most seeds we use are hand collected from wild populations by our natural lands staff. Each year we will collect seeds from numerous species of asters and goldenrods, a few sedge species, little bluestem, joe-pye weed, milkweed, oak trees, and birch trees.
There is more to seed collecting than one might think so the topic will be broken into two articles. In this article I will generally describe the practice of seed collecting. I will dive deeper into some of the rationale behind our seed collecting decisions in a second article for our December e-newsletter.
If you stop to think about them, you will agree that seeds are amazing. First, the basics: seeds are alive, and their cells breathe and use energy. They can die if you store them improperly. A seed’s DNA holds all the information required to build a mature plant and carry out its life cycle. Some are big (acorns, walnuts, coconuts) and some – such as for some orchids – are literally dust-like. Here in the northeastern United States many species have seeds that can lie dormant in the soil for years before they germinate.
Most people start learning about plants by studying their leaves and flowers, but collecting seed requires learning all about their fruits (the body that carries the seed; think of an apple). Deep observation is required. The first time you collect a species’ seed you are forced to visit that species in the field repeatedly and learn about its unique timeline. When does it flower? How long does it take for the flowers to be pollinated and develop fruit? How long does its fruit take to mature? If you do not visit the species frequently enough, you are bound to miss critical information, so you likely end up visiting the species more times than you need (keeping good notes is important). If all goes well, you have collected some viable seed and your confidence grows for the following year, but mastery does not come easily.
You must account for many environmental factors, so in subsequent years ask yourself these questions: Has it flowered yet or has the drought delayed flowering? Were the flowers pollinated or did something prevent pollination? Are the fruits developing or have they been destroyed by insects? Can I collect these fleshy seeds (viburnum seed, for example) before birds eat them all? It turns into a fun game of hide and seek, trial and error.
The best time to collect seeds is when they would naturally separate from the plant. The fruit that starts off green usually turns golden brown/black and the fruit literally falls right off the plant when you touch it or blow on it. The collector is too early if the seeds they find are too green, too hard, and still very much attached to the plant.
I usually put seeds into a small, labeled paper bag and store them in the refrigerator until they are ready to hand off to the Preserve’s propagators Megan and Brenna. Many of our seeds have evolved dormancy to ensure the environment is just right for germination; refrigeration provides for dormancy. Breaking the dormancy, cleaning the seeds of extraneous materials collected along the way, and careful sowing are the next steps in growing plants for the natural lands. The growers' work is equally fascinating, but I will leave it to them to write an article on seed cleaning and plant propagation.