A Guide to Native Wildflower Seeds
Gardening for pollinators is a great way to support biodiversity at home and improve the health of the ecosystem. Wildflowers provide food and habitat for wildlife, including bees, butterflies, birds, and other insects. Many of these pollinators rely on certain plants for nectar, pollen, or as a larval host plant. Incorporating native wildflowers into the landscape helps support pollinator populations, which in turn improves ecosystem health as well as food production.
Native plants also help to reduce erosion and stormwater runoff due to their robust root systems that stabilize the soil. Because they are adapted to the region, native plants are low-maintenance and require minimal water, fertilizer or pesticide.
Species Selection
Choosing the right species is an important step in starting a native plant garden. Planting species that are well-suited to your site conditions will increase the likelihood of successful establishment. Check the plant’s sunlight and soil moisture requirements and make sure it matches your site’s conditions before planting. If your site is prone to weeds, deer or drought, consider choosing species that are tolerant to those conditions.
When it comes to pollinator support and biodiversity, variety is the name of the game! Choose a combination of flowers with different bloom times, colors, shapes and sizes to attract all kinds of different pollinators and provide food and habitat for the entire growing season.
Timing, Stratification & Scarification
Many native wildflower seeds have a built-in dormancy to prevent seeds from sprouting at the wrong time. Breaking dormancy involves breaking down the hard coat of the seed (scarification) and/or exposing it to a period of cold temperature (cold moist stratification), depending on the type of seed. Giving seeds the proper treatment requirements will result in better germination rates and healthier plants!
Fall Sowing
The easiest method is sowing your native seeds outdoors in the fall after the first frost. This will allow the seeds to settle in the soil and ensure that they are exposed to the conditions needed to break dormancy. The freeze-thaw cycles in winter will break down the hard coat of seeds, and the cold temperatures in the soil during winter will naturally stratify the seed. Come spring, they will germinate on their natural schedule, giving them a full growing season to establish roots.
Artificial Treatments
If you missed the window to sow in fall or prefer to start seeds indoors, there are some methods to manually cold stratify and scarify your seeds. Treatment requirements can vary by species, so be sure to check the requirements for each species on your seed packet label.
Cold Moist Stratification Methods
Paper Towel Method:
- Sprinkle seeds onto a moist paper towel and fold it in half so all the seeds are covered
- Place paper towel in a Ziploc bag. Do not fully seal the Ziploc bag to allow for ventilation
- Put the Ziploc bag in the fridge for the number of days listed on your seed packet, checking periodically to make sure the paper towel remains moist
- Direct sow in pots or outdoors immediately after
Damp Media Method:
- Mix 1 part seeds with 3 parts damp media (vermiculite, perlite, or coarse sand). The mixture should be moist enough to form a ball, but not so wet that it drips water.
- Place mixture into a large Ziploc bag with a few ventilation holes and refrigerate for the number of days listed on your seed packet.
- Separate seeds from the media and direct sow in pots or outdoors immediately after.
Scarification Methods
Mechanical Scarification:
Use fine grit sandpaper or a metal file to gently scratch the surface of the seed until the seed coat is penetrated. Once there is discoloration, typically a white or light color, the seed coat has been penetrated, and you have successfully scarified your seed. Avoid removing the entire coat or damaging the seed embryo.
For larger seeds, you can also use a small knife or nail clippers to nick the top of the seed coat, being careful not to damage the embryo.
Always sow or cold-stratify your seeds immediately after scarification.
Non-dormant Seeds
Some seeds have no built-in dormancy and will germinate within a few weeks under the right conditions. These species can be sown in fall after the first frost or in early spring after the last frost.
However, planting these species in the fall is recommended. Although non-dormant seeds do not require cold stratification, exposing them to winter conditions can increase germination rates and produce hardier plants. Additionally, fall planting will encourage germination earlier in spring, giving a longer growing season and a competitive advantage over early-blooming invasive plants.
Seed Storage
If you plan to wait to plant your seeds, it is important to store them properly to maintain the seed’s viability. Seeds need to be kept in cooler conditions with low moisture content and little exposure to light. Seeds that are exposed to too much moisture are at risk of growing mold. Colder temperatures slow down the seed’s metabolic processes, which in turn slows down the rate of aging of the seed and prevents premature germination. Seeds should also be stored in dark areas, away from any windows or bright lights to avoid premature germination.
For short term storage (a few months to a year), you can keep your seeds in sealed containers or paper envelopes in a room that is cool, dry, and dark, such as a basement, pantry, or closet. For long term storage, consider storing your seeds in a sealed container in a refrigerator.
Sowing Instructions
- Ensure good soil contact – Remove any weeds, clear debris, and rake lightly to loosen the soil.
- Scatter seeds evenly by hand – For smaller seeds, mix with sand, cat litter, or vermiculite to avoid clumping.
- Gently press seeds into the soil – Use a roller or board or simply walk over the seeded area to secure seeds into the soil.
- Cover seeds with a thin layer of mulch – Use straw or shredded leaves, keeping it thin enough to ensure contact with sunlight.
- Keep seeds moist until established – Seedlings may need regular watering until they are established. Seeds sown in fall may require less watering than seeds sown in spring.
What to Expect after Sowing
Growing wildflowers from seed requires patience, but it is well worth the wait! The time between sowing your seeds and seeing them in full bloom can vary significantly by species and when they are planted. Some plants may begin to sprout just weeks after sowing, while others may take a full season or year to grow their roots before popping out of the soil. The time it takes a wildflower to bloom largely depends on its life cycle.
Annuals
Annual wildflowers complete their entire life cycle in one season. They typically germinate quickly and will bloom within the same season. Most annuals readily self-seed and will continue to bloom year after year.
Examples: Partridge Pea, Orange Jewelweed, Annual Toadflax
Perennials
Perennial wildflowers have a life cycle that spans several years, and they grow back from their root system each year. They spend their first year developing their roots and foliage, typically blooming in the second growing season. Most Maryland native wildflowers are perennials.
Examples: Milkweed, Golden Alexanders, Joe Pye Weed, Wild Bergamot, Asters
Biennials
Biennials complete their life cycle over the course of two years. Similar to perennials, they develop their roots and grow rosettes in the first year and will bloom in the second year.
Examples: Evening Primrose, Black-eyed Susan