Long before mankind existed, our planet was covered in dense, rich flora because Mother Nature gifted plants with the ability to self-propagate. Plants spread and naturalize in many ways, such as by creeping rhizomes, offshoots or pups, and seed without any help from humans. In our gardens, however, we feel the need to control this self-propagation and, oftentimes, we consider native plants that aggressively self-sow to be nuisance weeds.
As a garden center worker, I’m frequently asked, “Is this plant going to seed itself all over?” If I answer this question with a “yes, they do self-sow,” many customers tend to cringe and walk away seeking out something tidy and well behaved. On rarer occasions, the customer is aware of the benefits of self-sowing plants and immediately snags it up. Gardeners can sometimes be too tidy and unable to fully appreciate self-seeding plants. Deadheading every spent bloom will prevent plants from being able to set seeds. Desirable seedlings may also be pulled out by weeding too thoroughly.
Purchasing individual plants can become expensive, but self-sowing plants can quickly fill up a garden bed and give you multiples of your favorites. If seeds sow where you don’t want them, you can simply transplant them or pull them out like weeds. If plants are allowed to self-sow, short lived perennials do not to be replaced every few years. Self-sown biennials can also provide blooms in the garden year after year when they are allowed to go to seed. In addition, some plants will cross pollinate, creating unique and unusual varieties in your garden.
Many self-sowing plants are also natives and provide food for pollinators and other wildlife. To enjoy these benefits of plants, be sure to allow some blooms go to seed. Below are the top 10 self-sowing plants:
1. Columbine (Aquilegia spp.) – Perennial in zones 3-10. Columbine varieties can cross pollinate, creating new and unique varieties throughout the garden.
2. Hollyhock (Alcea spp.) – Hollyhock is a short lived perennial in zones 3-8. Stalks can simply be cut down in autumn and left so the seeds can self sow. Hybrid seeds may not result in true to type plants.
3. Blazing Star/Gayfeather (Liatris spp.) – Perennial in zones 3-9. This North American native is a favorite of native butterflies and bees. Liatris seeds require the cold temperatures of winter to germinate in spring.
4. Violet/Pansy (Viola spp.) – Violas are annuals and perennials. They grow best in the cool seasons of spring and fall. Self-sown seeds can produce flowering plants in the same year.
5. Bachelor Buttons/Cornflower (Centaurea spp.) – There are annual and perennial varieties of Centaurea that will happily self-sow in the garden. Also known as Mountain Bluet, the perennial varieties are hardy in zones 3-8.
6. California Poppy (Eschscholzia californica) – California poppy is a perennial in zones 8-10, but it is grown as a self-sowing annual in cooler climates.
7. Foxglove (Digitalis spp.) – There are biennial and perennial varieties of foxglove hardy in zones 4-10. Perennial varieties are notoriously short lived.
8. Milkweed/Butterflyweed (Asclepias spp.) – Native to North America, milkweed can be considered a nuisance weed because it self-seeds so profusely. Hardy in zones 3-10, there are different varieties of milkweed that grow naturally throughout North America.
9. Nasturtium (Nasturtiums spp.) – Perennial in zones 9-11, nasturtiums are grown as self-sowing annuals in cooler regions.
10. Morning Glory (Impomoea spp.) – Morning glory is an annual vine that easily self-sows and can grow more than 15 feet (4.5 m.) in one growing season.
