In my garden, I save seeds from certain plants every year and for others, I leave the seed for the birds. Seed saving is a great idea but whether or not you should save the seed depends on the plant.
If you are interested in saving the seed, ask yourself this: will you get the same plant as before? The first thing you need to find out is whether or not your plant is a hybrid or an open-pollinated plant. A hybrid is a plant that comes from the controlled cross breeding of two distinct species or cultivars. This is done intentionally to capture a desired trait such as flower color or disease resistance. If you saved the seed from this hybrid, the next generation will not look like your original plant. It will exhibit some of its parents’ (or even previous generations’) characteristics so you won’t retain the desired traits. For example, in September my Hibiscus syriacus ‘Lil’ Kim’ has interesting seed pods that look really easy to cut off, dry, and save. But this plant was deliberately created as a dwarf form of the species Hibiscus syriacus, commonly known as Rose of Sharon, a shrubby plant about 5 feet tall. If I planted the seeds next year, I would get a Hibiscus plant, that is one with hibiscus-like characteristics, but it may be small, medium, or large, with white, pink or lavender flowers.
If you have an open pollinated plant, the seed will produce the same plant as before with most flowers and herbs. There are exceptions in the vegetable world. There are some vegetables that self-pollinate such as tomatoes and beans so the seed retains the original characteristics. However, there are some vegetables that are pollinated by insects willing to travel to your neighbor’s garden to cross pollinate your neighbor’s vegetables with your vegetables. Peas, peppers, cucumbers, eggplants, melons, and squash are examples of vegetables that are cross-pollinated so the resulting seed may produce plants that do not have the same or desired traits as before. After you have decided whether saving the seed will result in the plant you want, consider these criteria:
1. Do you have enough of the plant or want more?
This spring I planted love-in-a-mist seeds (Nigella damascena), which I bought from the Green Spring Gardens gift shop in Alexandria, VA. Green Spring Gardens has stands of these small lavender-blue flowers that produce very interesting seed pods, perfect for dried flower arrangements. My seed only produced a few plants but fortunately, they flowered and produced seed. I want the seeds to disperse and germinate in the garden next year in the same place to get more plants (hopefully a stand of them just like at Green Spring Gardens). I could do this manually by saving seeds and planting next year or I could just let nature do it for me. I left the seed pods in the garden.
On the other hand, I have a few columbine plants, Aquilegia columbine, growing in one place. I would like for them to grow in other places on the property so I cut the seed pods and put them in a paper bag. Later, when they were bone dry, I pulled the pods apart and put the tiny, glossy black seeds in a glass jar.
2. Is the seed useful in the kitchen?
I always grow plenty of dill and cilantro, some of which I harvest the leaves for cooking, some of which I leave alone and let the plants flower and “go to seed.” When the seed heads are brown, I cut them and let them drop into a paper bag and let dry some more. The dill seed is great for breads and rolls, the cilantro seed, which is known as coriander, is great for cookies and fruit salads. Sometimes, I use the seed for the garden the next year, just depends on how much baking is done in the winter.
3. Do you find it easier to save seed or just buy again next year?
The corollary being, how much time do you have? There are two basic methods for saving seed: dry and wet. With most of my herbs and flowers, I use the dry method because the seed themselves are in a dried pod so it is simple to cut the pods and put it in a paper bag. After a few weeks, when very dry, I put them on a plate, separate seed from the pod, and put the seed in a glass jar with a label. With pulpy, fleshy vegetables, I use the wet method. Parts of the fruit, such as tomatoes, are cut up or mashed and put in a jar with water. After days, depending on the plant, you eventually extract the seeds from the pulp and lay on a paper towel to dry. The exact process depends on the vegetable. For detailed information on how to save seed (and for buying open pollinated seed), check out the Seed Savers Exchange (under the “Education” tab) and Southern Exposure Seed Exchange (under the “Growing Guides” tab).
4. Do you want to attract birds or create winter interest?
If you want to feed the birds or try to achieve some architectural interest in the garden in the winter, you have to leave the seeds on the plants. I grow a lot of lemon basil because I use some plants for cooking while leaving others in the garden to flower and set seed. In late summer through fall, the yellow finches land on the swaying seed stalks and peck at the seeds. I also leave the coneflower (Echinacea) and black-eyed Susan (Rudbeckia) plants alone. After they flower, they have stiff seed stalks and prominent seed heads that add interest in the winter and provide food for birds.
This September, my rue plant (Ruta graveolens) produced interesting seed heads far above the foliage. Rue is a well known herb but I use it as a landscape plant. Its gray, green foliage provides a lot of color and texture, it is drought resistant and seems to repel deer and critters, and it provides yellow flowers in the summer for me to cut and place in vases for the office. I was torn between harvesting the seed for more rue plants next year or leaving the seed heads for winter interest when I read that rue is a great companion plant for alpine strawberries (which I just grew this year) and for raspberries (which I also planted in my garden). Off with her head!