STARTING NATIVE PLANTS
for Butterflies & Hummingbirds
Native plants often prove superior to non-natives both as nectar plants and butterfly caterpillar food plants. Unfortunately, many are not available commercially at many nurseries. In addition, many require special germination and planting procedures that may not be familiar to gardeners who are used to "typical" gardening.
These instructions are preliminary and will be updated to reflect experiences our members have in developing their backyard habitats.
ACQUIRING NATIVE PLANTS
1) Never collect plants from the wild. We have too few in the wild to remove any!
2) Buy plants from suppliers who grow their stock from seed, cuttings, etc. NOT from those who sell plants collected directly from the wild.
3) Talk to the supplier about how the plants were grown. Plants grown outdoors will often prove to be superior to greenhouse plants. Greenhouse grown plants will need to be "hardened off" (ie taken out doors slowly) to prevent shock.
4) When collecting seeds from the wild, always insure that a majority (preferably a large majority) of the seeds remain at the location of collection. Many of the plants, even so-called "perennial" wildflowers depend heavily on annual distribution of seeds for continuation of a colony. Many of the ones we recommend are also important wildlife food sources so don't starve the wildlife.
5) When buying seeds, try to buy locally grown though this will be the most difficult of all. Recommendation: Check availability of seed at Bowman's Hill Wildflower Preserve, PA before buying from a mid-west supplier but . . .
GROWING NATIVE PLANTS FROM SEED
Reference book: Phillips, Harry R., Growing and Propagating Wild Flowers, An easy-to-use guide for all gardeners, The University of North Carolina Press. Available from NJ Audubon stores and many other retailers.
Different types of seeds have different needs. A good reference book like the one above will help greatly. Some of the special considerations include the need for a period of dormancy (stratification), the need for the seed to be continuously moist, and the need for sunlight to break dormancy or the need for the seed coat to be damaged.
1) DORMANCY: Many native seeds lie dormant through the winter (sometimes for several years) before they germinate. Planting these seeds requires duplication of this natural condition by subjecting them to moist, cold conditions for a period of time (Stratification). This time is typically about 60 days but can be a little as 30 days or as long as 120 days. Check references and note that they may differ in their information! Stratification methods:
a. The easiest way to "stratify" seeds is to plant them in pots during the late fall or winter. Moisten the soil and seal the pot inside a zipper sealed bag. Keep the pot in an outdoor location, out of the sun, until the seeds germinate. Transplant to individual pots after the first "real" leaves appear.
b. A little trickier technique is to mix the seeds with a small amount of moist (not dripping wet!) sand. Seal the mixture in a zipper sealed bag in the refrigerator. Check at least weekly for any germination and plant immediately. (Note: I am not diligent enough to check regularly and have lost many seeds to premature germination when I used this method)
2) Some plants produce seeds that will not survive if they dry out (desiccate). Examples include Jack-in-the-Pulpit, Twinleaf, Bloodroot, Ginger, and Trillium. These seeds must be collected and planted immediately, even if they won't germinate until the following spring, or even a year or two later.
3) Some of the seeds require light to germinate (usually the really tiny seeds). They must be sown on the surface with NO soil covering. Best to firm potting soil slightly, then cover with a thin layer of fine milled sphagnum moss and spread the seeds on top of that. Examples: Penstamon digitalis, Lobelia sp. (including Cardinal Flower), violets.
4) Some larger, thick walled seeds must be "scarified" before planting. Scarification can be accomplished by scratching lightly with a file, soaking in hot water to break the seed wall, dilute acid treatments, or digestion in the stomach of an animal! Best to check several references for recommendations on the planting of these seeds.
1) Recycled pots need to be sanitized before use to prevent the possible spread of unwanted organisms: Soaking in a dilute (1:10 solution) of household bleach for at least 30 minutes will work for this
2) Use of soil collected from outdoors is not generally recommended but can be done for your own use if the soil is sanitized by heating in a conventional oven at 275 degrees F for at least 30 minutes. A microwave can also be used by placing soil in plastic bags for about 10 minutes. WARNING: If using the microwave, do not fill bags too full and leave an opening for steam to escape!
3) A commercial potting mix with a small amount of "balance" fertilizer is ideal.
4) A cold frame is an ideal growing location. Cold frames should face north or north east to prevent over heating of the plants. Greenhouses are not useful until plants are established and even then, native plants prefer our native weather. Any greenhouse grown plants should be "hardened off" for best results. Cover cold frame with translucent (not transparent) plastic or similar material. Keep out rodents with hardware cloth.
GROWING 4 TOP NATIVE PLANTS
Swamp Milkweed (Asclepias incarnate) Super nectar plant for many butterflies throughout much of the summer; monarch caterpillar food plant. Produces good seeds for subsequent plantings; collect seed pods just before they burst and separate seeds from "fuzz" immediately. Requires 30 days stratification, cover seeds lightly, most should germinate.
Cardinal Flower (Lobelia cardinalis) Super for hummingbirds, OK for some larger butterflies, very attractive to humans. Seeds require about 60 days of stratification and must have light for germination. Don't plant too densely; most seeds will germinate and they are tiny. Plant in full sun to partial shade. Grows in wetter areas in the wild but does very well in a garden of "typical" watering.
Purple Coneflower (Echinacea purpurea) Although native to the Midwest prairies this plant grows well in NJ and provides a great addition to the garden both for humans and wildlife. Great for many butterflies. Seeds favored by goldfinches in late fall. Does best with some stratification but some will germinate without. Cover seed lightly with soil.
New England Aster (Aster novae-angliae) Super fall butterfly nectar plant. Goes well planted with golden rod for purple and gold fall garden. Requires at least 30 days of stratification. Cover seeds lightly. Many will not germinate so plant a few extra.
SIMPLE GERMINATION PROCEDURE
FOR SEEDS REQUIRING STRATIFICATION
1) Fill a 4" pot with a good moist potting mix. Tamp down to firm the soil. Leave about 1" of space at the top.
2) Cover with about ?" of finely milled sphagnum moss (available at good garden centers).
3) Spread seeds on the sphagnum (About a dozen larger seeds such as milkweed; a few more than that of small seeds like Cardinal Flower)
4) (If seeds require light to germinate skip this step) Cover with about ?" of potting soil and firm down.
5) Moisten surface.
6) Seal the entire pot in a 1 gallon zip top plastic bag.
7) Place outdoors in a spot of total shade (against the north side of the house is ideal) for the required stratification period. If it is too late for outdoor conditions, pot can be put in the refrigerator.
8) When seeds germinate, open the bag, water well, and treat as any other plant.
9) Transplant to individual pots or directly into the garden after the first "real" leaves are fully developed and before root systems have intertwined.