One of the best sources for information is The Xerces Society. There is a wealth of information listed as well as how to find seeds for your zone. Take some time and investigate the entire site!
One very important fact located on the link part way down their home page titled Finding Milkweed Seed for you State is about using milkweeds that are native to your area. They state: We encourage you to only plant milkweed species that are native to your area. The Biota of North America Program’s (BONAP) web-based North American Plant Atlas provides county-level distribution information for all Asclepias species in the lower 48 states (milkweeds are not native to Alaska and Hawaii). Please refer to BONAP’s map color key for detailed information, and note that dark green indicates that the species is present within the state, while bright green shows that the species is documented to occur in that specific county. However, these maps do not convey the abundance of the species within each county. Three Asclepias species have been introduced to the United States: tropical milkweed (A. curassavica), African milkweed (A. fruticosa), and swan or balloon plant (A. physocarpa). Of these, tropical milkweed (also called blood flower or scarlet milkweed) is the most widely available from commercial sources. However, there is preliminary evidence that where tropical milkweed has been introduced, its presence may cause monarchs to reproduce outside of their regular breeding season, disrupt monarchs’ migratory cycle, and increase transmission and virulence of the protozoan parasite (Ophryocystis elektroscirrha). Thus, some monarch scientists are concerned that the planting of tropical milkweed may lead to negative impacts on monarch health. For more information on this topic, please download this fact sheet by the Monarch Joint Venture or read this Q&A, also from the Monarch Joint Venture, about research related to tropical milkweed and monarch parasites
Native milkweed grows very large and can tend to be invasive. This is a problem for some of us with smaller, urban yards. We investigated the descriptions and came up with several seed choices that we wanted to try. One of these, Prairie Milkweed, is not listed in WV, but it is present in OH and KY. We are only 60 miles from those borders and felt safe trying this one. Our best source for seeds from the links listed was Prairie Moon Nursery. There is one additional plant we wanted to try - Asclepias purpurascens, but seeds are scarce. Purple milkweed is a shorter, less invasive variety of Asclepias syriaca (Common Milkweed). We signed up for a waitlist on two suppliers and finally found some this week on Everwilde Farms.
Below are the varieties that we are trying and the descriptions are from Prairie Moon Nursery.
Asclepias incarnata Rose Milkweed, is also commonly called Red Milkweed, Marsh Milkweed, or Swamp Milkweed. That lovely vanilla fragrance you detect coming from large rosy pink flowers possibly hosting several Monarch or Swallowtail butterflies is Swamp Milkweed. This deer-resistant plant grows in moist to average soils, and blooms in July and August. Later, large pods form which will break open to reveal seeds that will float away in the wind. If growing Rose Milkweed from seed, try fall planting - or if planting in spring be sure to first moist-cold stratify the seeds for a month. Large numbers of Rose Milkweed can often be seen growing in wetland settings.
Asclepias verticillata Whorled Milkweed has very skinny, "whorled" leaves. There are clusters of approximately 20 flowers near the top of each plant. Whorled Milkweed can bloom anytime between July and September, which is later in the year than many other Milkweeds. The white flowers can be a greenish-white on some plants. When the Whorled Milkweed is mature it reaches a height around 2'. The nectar of the flowers attracts many kinds of insects, including long-tongued bees, short-tongued bees, wasps, flies, butterflies, skippers and beetles. Whorled Milkweed is deer and rabbit-resistant.
Asclepias viridis Spider Milkweed shares with other Asclepias species its milky, irritating sap and strong attractiveness to Monarch butterflies and a host of other insects. Very tolerant of dry conditions, it is also called Green Antelopehorn. Spider Milkweed features rose-white flowers surrounded by green that form in showy umbellated clusters, often one per plant. Its beauty and tendency to spread slightly make it a good garden choice.
Asclepias sullivanti Prairie Milkweed is the winner of the 2015 Green Thumb Award for best New Product. Also called Sullivant's Milkweed, named for William Starling Sullivant, an American Botanist of the mid-1800's. This Milkweed appears generally similar to Common Milkweed but is less aggressive, has slightly smaller flowers, and an overall smooth appearance on the stem, leaves and seed pods. Visited by hummingbirds and a wide variety of bees and butterflies (including, of course, Monarchs), Prairie Milkweed is one of the plants favored by the larvae of the Milkweed Leaf-Miner fly, which bore holes in the leaves. Easily grown from seed and bearing a very fragrant flower, Prairie Milkweed makes a nice addition to any sunny medium to medium-moist garden. After just a few years the taproot will extend very deep, protecting the plant in times of drought, but also making it difficult to move so choose your spot wisely.
And, from Everwilde we found the Asclepias Purpurascens. This excerpt from Native Plants and Wildlife Gardens: An Unsung Asclepias (guest post by Barbara Pintozzi) says it beautifully:
Asclepias purpurascens makes an excellent garden plant, as it is not aggressive like swamp milkweed. It prefers partial sun, but it will grow in full sun or light shade. It will grow in average garden soil and actually does best in clayish soil. It is distributed from Ontario south to Texas and Georgia, but is endangered in Wisconsin and Massachusetts (USDA). It blooms in mid-to-late June in my Zone 5, Chicago-area garden. It reaches 2 to 3 feet in height.Why purple milkweed is so hard to find and isn’t better known is beyond me. This plant should be made more wildly available to gardeners east of the Rockies as a tough, beautiful, reliable workhorse.
Some propagation notes:
The GCA Seed Share Vice-Chairman, noted that this can be another difficult plant to propagate. Other sites, too, suggest that some asclepias need to be babied and may not bloom until the second year. Asclepias have tap roots and transplanting can be difficult. A call made to Prairie Moon helped and they were extremely helpful in germination suggestions. All of our seeds need to go through 30 days of cold stratification. Although the literature from Prairie Moon suggests stratification and germination in sand, they also told me that their propagation staff uses a coffee filter method. A little research turned up 'The Baggie Method.' Always up for a challenge this is the direction we took. Read the link above carefully. This is what we did:
- Used cone shaped coffee filters, moistened in a pan of water. (If too moist, set briefly on a clean dish towel to absorb some of the water).
- Opened the coffee filters.
- Put 4-6 seeds inside the coffee filter.
- Folded the sides and top of the coffee filter over to insure that the seeds don't slip out (which happened on my first effort).
- Stapled the top of the filter closed,
- Inserted the coffee filter in a sandwich size zip topped baggie.
- Close the baggie almost all the way.
- Inserted a straw into the small opening and blew air into the opening and quickly finished zipping up.
- Marked each baggie with the variety and date.
- Put on the refrigerator shelf for 30 days.
- Do not use tweezers to handle seeds or when transplanting. Use toothpicks to aid in transplanting. Tweezers are too sharp for delicate roots and will cut the root in half. Gently pick up with two toothpicks.
|"The Baggie Method"|
Notice putting air into the baggie!
As she suggests, we will check our baggies regularly to insure they stay moist. If germination starts then we will pull the baggies out and pot up.
Instead of going into 4-6" pots, we will follow the suggestion from another source that says plant several seedlings in 1 gallon plastic containers. Place in a protected place and grow as you would other seedlings - keeping adequate moisture, diluted fertilizer. You will need to judge when your plants are ready to go into the ground. The advantage of the larger pots is that you can cut the bottom out and place in the garden where you want them placed - you could even sink the pots into the ground with the bottom removed and the tap root will go straight down into the soil and no moving necessary. The sides of the plastic pot can then be lifted when the plants are mature enough to leave on their own. We will again use our water jugs for this as the plants can be planted pretty deep in those and the jugs will serve the same purpose as the plastic garden pots.
|Supplies laid out on the counter. Coffee filters, |
pan of water, seeds, baggies.
|Seeds placed inside the filter.|
|Baggies are ready to go in the fridge.|
Each type of Asclepias has a separate page with details on germination through potting up. Our ongoing journal will continue here starting with 2-3 year plants.
May 2017 Our plants are now entering their third year. Several members have had great success and plants are still coming up. The aging of the plants as well as climate change is definitely affecting the time that they break dormancy. Last year my plants were slow to break, waiting until May. This year with a very mild winter they showing their tips in late April. Kathy has hers located in a planter on her driveway as it is the one area in her yard that gets enough full sun to support milkweeds.
|May 14 and blooms appearing already on her Asclepias incarnata|