Wild About Texas – October, 2007
Most of Texas has been blessed this year with a wetter than normal summer, making it a choice time to harvest wildflower seeds for fall planting. The following techniques apply to seed collecting at other times of the year as well.
Identifying plants and gathering seed can be tricky if the plant is out of flower. Mark the plant with a small flag or surveyor’s tape while it is still in bloom to help you find the plant later. Collect seed only from species that are growing abundantly in a given area so as not to deplete the potential for future generations. Taking less than one-tenth of the seed in a population will leave enough for reproduction and collecting from a number of individuals will ensure genetic diversity. If you are collecting on land that is not your own, remember to get permission from the landowner ahead of time.
Timing is crucial for successful seed collecting. Most seeds or seed pods are ready to harvest when they reach full size, turn dark in color, and are firm and dry. Fruits surrounding seeds are typically mature when the flesh becomes soft and changes from a green or yellowish hue, to red, gold, blue-purple, or other color.
Collecting too early may result in germination failure or seedlings that are stunted or puny. By harvesting too late, some fruits and seeds will fall pray to mold, insects, birds or other animals. Tardiness may jeopardize your window of opportunity if seeds have fallen or capsules have dehisced (split open and expelled seeds). Many pods or capsules mature and dehisce at staggered intervals, making it difficult to collect more than a few seeds at a time. Tying a cloth sack over the immature seed (flowers must be pollinated first to ensure fertilization) can make collection much easier.
Some species will accept being collected just before the pod or seed capsule turns completely brown and dries. In this case, allow the harvest to cure before storage by arranging it loosely in a single layer on a shelf, screen or tray in a location with good air circulation. Another option is to dry the seed in a closed paper bag, again, loosely packed and well ventilated to shirk mold. Some pods or capsules may not split open on their own and may benefit from gentle crushing to release the seed. The pulp should be removed from seeds with juicy or fleshy fruits to avoid decay.
Separating chaff from the seed will reduce the space needed for storage and abates the risk of insect infestation, but isn’t necessary if the seed is to be planted directly into the ground or into pots of soil. Seed relegated for storage should be labeled with the name of the species (common and/or botanical as suits your needs) and date of collection. You may find it helpful to include the name of the collector and the geographical source of the collection as well. Provide storage conditions that protect the seed from insects and rodents. Low humidity, darkness, and cool temperatures increase shelf life. Airtight containers and plastic bags should only be used if the seed is completely dry, and paper bags or envelopes that allow for breathing and are good choices as well.
The length of time that seeds may be stored before losing viability will vary from species to species, and conditions of storage. Seeds of fleshy fruits and many annuals should generally be planted within a year, while others may safely be stored for 10 years or more. The sooner seeds are planted after harvest, the higher the rate of germination.
Check back with “Wild About Texas” next month to find out how to use the seeds you’ve collected to create a wildflower garden.
For information about native plants and the Lady Bird Johnson Wildflower Center, go to www.wildflower.org.
About the author: Andrea DeLong-Amaya is Director of Gardens and Growing at Lady Bird Johnson Wildflower Center in Austin. Find out more about native plants on the Wildflower Center Web site at www.wildflower.org.