Seed pods of redbuds

One of the enjoyable and important activities I do each year at this time is collecting seeds. There are many plants for which other propagation methods make more sense, but seed propagation is important for annuals, perennials and even some woody plants. These seeds when properly stored and grown will yield plants that will someday be part of our plant sale, or are planted in the landscape at Bullington Gardens.

There are a few things to consider when collecting seeds. Hybrids, those plants that are the result of cross pollinating two different parents, do not necessarily grow true. This means they will express traits from previous generations and not be the same as the plant the seeds were taken from. Collecting seeds from open pollinated plants (non hybrids) will yield more reliable results.

Collect seeds that are fully mature, or come from ripe (even over ripe) fruit. Make sure the plants are robust, healthy and free of disease as much as possible.

Seeds need to be fully dry before storing them away. They are best stored in cold, dry environments and can be done in a jar, or plastic container in the refrigerator.

Some plants, such as marigolds, zinnias, coneflowers and black-eyed susans produce naked seeds. These can be simply pried out of the seed head and separated from the chaff. and dried.

Seed head of a marigold

Other seeds are produced in pods or capsules, such as beans, columbine, redbuds, native azaleas. Once these become brown and dry, seeds can be removed and further dried before storing.

Other seeds develop inside fleshy fruit such as pumpkins, peppers, Solomon seal, and kousa dogwood. These seeds need to be extracted and have any fruit residue washed off. Some seeds, like magnolias, have a waxy coating that is not easily removed. But leaving this waxy fruit will inhibit germination. Tomato seeds have a gelatinous coating that is best removed by squeezing the contents of the tomato in a cup and letting the whole mess ferment for a few days. They can then be washed in a sieve and left to dry on a paper towel.

When it comes time to plant these seeds, it’s important to check whether either internal or external dormancy (or both) is a factor for each plant type. Vegetables and annuals are usually ready to plant anytime. However some, like moonvines, do have very hard seeds and exhibit external dormancy. These need to be softened or scratched (scarification) before they will germinate. Many seeds from perennials and woody plants exhibit internal dormancy. These seeds typically need to experience winter-like conditions (stratification) before they will germinate. This can be done by mixing seeds with damp sand in a plastic bag and placing in the refrigerator for a few months. Knowing exactly how long to do this for each plant will take some further research, since all are different. Or another method is to plant seeds in containers outside and let winter do the job it would normally do.

Collecting and growing seeds is a very gratifying activity. It can save a gardener money on purchasing seeds and gives them more options on plants to install in the landscape. However, patience is definitely needed.