Lady Bird Johnson Wildflower Center
Guidelines for Seed Collecting
4801 La Crosse Avenue
Austin, Texas 78739-1702
512- 292-4200
www.wildflower.org
Educating people about the environmental necessity, economic value, and natural beauty of native plants
Seed Harvesting
Most wild seeds are collected by hand because the desired species usually do not grow in pure stands and the site’s topography often limits the use of mechanical equipment. Plants are easiest to identify when they are flowering, so it is a good idea to mark individual plants with surveyor’s flagging tape, or to write down specific landmarks to help you relocate populations when the seeds are ready (For example: 6 miles from town on Farm Road 12 by an Adopt-a-Highway sign on the south side). Always get permission from the landowner when collecting on private
land. Never collect on public land. Areas destined to be developed or destroyed in the near future provide excellent sites for collecting seeds, provided the landowner has given permission. Never collect seeds from rare or endangered species—collect only from plants that you find growing abundantly in a given area, to ensure that you do not eradicate an isolated population. Take at most, only one-tenth of the seeds so that enough seeds are left to reseed and perpetuate the stand. Collecting seeds at the correct time is crucial for propagation to be successful. Gather fruits from the ground only if they have recently dropped. Reject fruits or seeds that have been on moist ground for some time, or any seed that may have begun to decay, mold, or become infested with insects. They could contaminate the rest of your seed harvest if combined with other seeds during storage. Delayed harvesting of species with persistent pods often results in insect-infested seeds. The tools and material you will need depends on the size of the harvest. Basic equipment includes gloves, boots, drop cloths, pruning shears, boxes, baskets, paper bags, and/or canvas bags. Although plastic bags may be used for collecting, storing seeds in airtight containers or plastic bags will encourage mold growth. Many plants can be stripped by hand or the seed can be beaten onto drop cloths.
Seed Maturation
Proper seed harvesting is aided by an understanding of seed ripening, dispersal mechanisms, and the influences of weather on the timing of seed maturation. Flowering and fruiting dates vary from year to year. You should be familiar with the approximate flowering and fruiting dates and then be able to recognize mature fruit or seeds. An early spring and dry summer, for example, may cause seeds to set early. Seed quality also varies from year to year and from location to location. Experience is often the best teacher in learning to determine whether a seed is mature. When seeds are mature you should begin collecting. Mature seeds are usually dark in color, firm, and dry. Seeds that are green and moist are immature and generally will not germinate or will produce unhealthy seedlings. The flesh of pulpy fruits often becomes soft and changes
from green or yellowish to reddish or blue-purple when ripe. Seeds are often mature a week or more before the fleshy fruits turn color and fall from the plant.
Seed Cleaning and Preparation
Seeds should be collected just before, or, as the pod or capsule turns brown and dries, and before it dehisces. The pods should be dried in single layers spread thinly on canvas cloths, screens, or trays elevated from the ground. Curing on the pod may take longer for species other than legumes. Air-drying takes one to three days, depending on the humidity. After the seeds have dried, you can extract them from the pods by beating or thrashing. A mature pod
will often twist and split open to drop the seeds. Although not all seeds need to be cleaned before storage, those with pulpy fruit should be cleaned to reduce mold. Remove the pulp of large fruits by hand by rubbing on a screen or mashing with a wooden block, rolling pin, or fruit press being careful not to damage the seed.
Seed Storage
The two most critical necessities for storing seeds are constant temperature and low humidity. A temperature of 50 degrees Fahrenheit or less and 50 percent humidity or lower is ideal. In general, fluctuating temperature and humidity harms seeds more than slightly higher constant values of each.
Store seeds in the refrigerator, not the freezer, until you are ready to plant. Low temperatures, humidity, and darkness protect seed longevity. If it is not practical to store seeds in your refrigerator, store them in any place that is cool, dark, and dry, protecting them from insects as much as possible. Store the seeds in paper sacks to allow good air circulation and prevent molding. Do not store seeds in plastic bags.
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