When it comes to collecting wildflower seeds, timing is everything. If the seed is collected too early, it will not be viable. Waiting too long will produce empty seedpods. The trick is to collect the seed at precisely the right time. This, however, is not always easy.
After collecting and propagating wildflower seeds for over 30 years, I've developed hundreds of little techniques for collecting, hulling, cleaning, sorting, and storing seeds. These methods vary with each species, and all this information could easily fill an entire book. With the limited space of this article, I'll only touch on a few of the most important tips.
If you plan to collect seeds from the wild, make sure you get permission from the owner of the property in question. The Tax Assessor's Office at the local Town Hall can supply the name and address of the owner of any property. Without permission you may be stopped by the police, a conservation officer, or the property owner who may charge you with trespass and theft! Once you have permission to collect seeds, don't take more than you need. In, the case of rare species, only a few seeds should be collected. Leave most of the rare plants alone so that they may self-sow and perpetuate the species.
No matter what kind of wildflower seeds you intend to collect, you must keep a constant watch on the plants involved. Even though a plant may produce flowers there is no guarantee that you will be able to collect the seeds. Some plants may not produce seeds due to poor pollination. Steady rains, unreasonable temperatures, and strong winds affect the activity of bees and other insects that pollinate wildflowers. "Critters" such as squirrels, mice, voles, chipmunks, insects and birds all keep a watchful eye on their future pantry supplies and will often beat you to the punch for the seeds. Ants are especially talented when it comes to collecting seeds. Ants will often outwit you when it involves seeds of Trailing Arbutus (Epigaea repens) and Fringed Polygala (Polygala paucifolia). With these two species it is usually necessary to wrap the green seed pods in tiny cheesecloth bags while the seeds ripen on the plants.
Assuming you out-smart the critters, check the plants constantly. As a general rule, most seeds start to ripen when the pods or capsules change color Or when the seed heads start to open. Some seeds such as Hepatica (Hepatica sp.) and Rue Anemone (Anemonella thalictroides) are ripe when the seeds are still green, but a careful touch with a finger will loosen them. Wildflowers that produce many seed heads or capsules on a single stalk like Cardinal-flower (Lobelia cardinalis) or Blazing Star (Liatris sp.) will ripen their seeds over a period of weeks.
You can pick the ripe ones every day, or you can cut off the entire stalks when the first few seed heads or capsules are fully ripe. Store these stalks in tall paper bags indoors, leaving the bags open at the top. This will allow good air circulation and prevent the seeds from becoming moldy. Check the stalks from time to time, and shake them vigorously inside the bag so the seeds will fall out of the capsules. Seeds that fallout can be carefully poured out of the bag while the rest continue to ripen. There is usually enough nourishment and moisture in the stalks to allow most of the seeds to ripen.
Seeds should be collected when they are thoroughly dry, using paper bags or paper envelopes. Don't use plastic bags for gathering seeds. The plastic creates static cling that is a real problem for very tiny seeds. Plastic also prevents the necessary drying process and will create mold and rot the seeds. Moisture from rain or dew can ruin seeds very quickly. If seeds must be collected when they are wet they should be spread out in shallow boxes to air-dry indoors. Shoebox lids are excellent for this purpose, and can be lined with paper towels or tissues to absorb the moisture.
It is also a good idea to air-dry most species of seeds that have been hulled. Dishes (not plastic) or shallow boxes work equally well as long as they are big enough to spread the seeds out in a single layer. This not only prevents spoilage but also allows tiny insects to escape or be destroyed before the seeds are packed for storage. Cleaning and drying the seeds carefully will insure good results. Seeds that are stored in their pods or seed heads will usually harbor insects and their that over time will destroy most of your crop.
Some seeds such as Wild Columbine (Aquilegia canadensis) or Bishop's Cap (Mitela diphylla) are very easy to collect. The pods are urn-shaped and open when ripe, revealing the seeds in their little cups. Just bend the stalks a bit and tap the pods. The seeds will fall.
Geranium (Geranium maculatum) are best handled by cutting the ripening stalks and putting them in a closed paper bag. The pods will pop open when ripe and the seeds are easily poured out of the bag. Don't put too many stalks in the bag, as overcrowding reduces the air circulation and induces mold.
Wild Blue Lupine (Lupinus perennis) and Goat's Rue (Tephrosia virginiana) have very fleshy seed pods that explode. These pods will turn moldy in only a few days if they are put into paper bags. These pods should be thinly spread out in shallow boxes that are tightly covered with bridal netting. This netting is inexpensive and can be purchased at any fabric store. The netting allows good air circulation to prevent mold and the seeds will fall to the bottom of the box when the pods pop open.
Wildflowers that have berries or fleshy fruits require special treatment. They should be collected when they are obviously ripe. Extracting the seeds is a difficult chore and techniques vary with each species. Whatever the species, these seeds should have all the fleshy parts removed. These seeds should then be thoroughly cleaned and air-dried before planting or storage.
Some berries can be temporarily packed in sealed plastic bags and left at room temperature until the fruits rot and turn brown or black. This smelly mush can then be put into a strainer or collander. Rinse thoroughly under tepid running water to wash away the flesh. Mashing the pulp with a wooden potato masher or wooden spoon helps to separate the seeds from the pulp. These seeds should then be completely air-dried. For these fleshy seeds I use typing paper for drying rather than paper towels. Unless every speck of pulp is removed from these seeds they will stick to paper towels like glue.
These are just a few hints on collecting wildflower seeds. Time, patience, and experimentation will lead to good results. Whatever the species, wildflower seeds should be cleaned of debris, air-dried if necessary, and then planted or stored. There are a few species such as Bloodroot (Sanguinaria canadensis) and Swamp Pink (Helonias bullata) that should be planted as soon as they are ripe and not allowed to dry at all, but these are exceptions to the rule.
Seeds can be stored in paper or glassine envelopes or glass vials. Plastic vials from prescription medications can sometimes be used, but they are not recommended for very tiny seeds. Static will cause tiny seeds to cling to the sides of the container, making them difficult to remove. Packed seeds can be placed in glass jars or coffee cans stored in the refrigerator until planting time. If coffee cans are used they can be left outdoors in a protected spot during the winter. The alternate freezing and thawing of outdoor temperatures actually increases the percentage of germination of some seeds. Collecting your own seeds can be fun and certainly insures that the seeds are fresh. The fresher the seed, the better the germination.