DetailsPurple Milkweed (Asclepias purpurascens) is a rare and showy Milkweed species. This Mid-western wildflower is a host plant for Monarch populations in the middle portion of the US. A robust grower, Purple Milkweed does well in most any soil and appreciates moisture. Spreading by underground rhizomes, Purple Milkweed is best grown in unused areas of your yard, along ditch banks and fences where it can spread without overrunning other perennials. Good companion plants include Helianthus (perennial Sunflower) and Beebalm (Monarda).
HBLHY21 (Plant - 2.5" deep pot) - Out of stock.
HBLHY51 (Plant - 5" deep pot) - Out of stock.
|Common Name||Purple Milkweed|
|Botanical Name||Asclepias purpurascens|
|Zones||3, 4, 5, 6, 7, 8|
|Light Requirements||Full Sun|
|Flower Color||Pink, Purple, White|
|Mature Height||24-36" tall|
|Mature Spread||12-36" wide|
|Bloom Time||Early to mid summer|
|Ships As||Potted Plant|
|Planting Time||Spring / Summer|
|Soil Type||Sandy Soil, Average Soil, Low Fertility Soil, Well-Drained Soil|
|Soil Moisture||Average, Well Draining|
|Amount of Rain||20 to 30", 30 to 40"|
|Advantages||Deer Resistant, Attract Butterflies, Bee Friendly, Native, Good for Erosion Control, Low Maintenance, Multiplies / Naturalizes|
|Ideal Region||Coastal California, Northeast, Midwest, Southwest, West, Pacific Northwest|
|Neonicotinoid-Free||Yes - Learn More|
|Ships to Hawaii, Alaska & Canada||No|
Asclepias (Milkweed) are sun loving plants that are essential perennials for monarch butterflies providing food for caterpillars and nectar for adult butterflies. They bloom from mid-summer into early fall and, with their milky sap, are resistant to rabbits and deer.
Asclepias can be divided into two groups for plant care; Asclepias tuberosa with orange (sometimes yellow) flowers and all the other species with pink (sometimes white) flowers.
- Asclepias tuberosa (Orange Butterfly Weed) - this perennial stays dormant until later in the spring than many other plants, especially when grown in pots. It's fine to plant dormant plants; don't up-pot them for planting later in the growing season.
Preferred growing conditions:
- Need sandy or gravelly soils (except the Clay form which does well in heavier soils including dry clay.)
- Does best with gravel mulches.
- After their second growing season, only requires deep but infrequent watering. Plant in full hot sun.
- Just a few handfuls of compost and Yum Yum Mix added to the planting hole is enough. Don't plant into a rich, highly-amended soil.
- When planting dormant plants, water thoroughly after planting and wait to water again until the plant comes into active growth, at which time a deep watering every week or so is adequate. Take care not to overwater young transplants.
- Asclepias has a long, carrot-like tap root that should remain undisturbed after planting and should NOT ever be divided.
Preferred growing conditions:
- These species grow in a wide range of soil types, including clay.
- They don't need mulching (except in very hot climates).
- These are moisture-loving perennials and do well in wet to moderately moist soil conditions.
- Plant in full to part sun areas.
- They like compost enriched soils at planting time.
- Asclepias syriaca and A. speciosa will spread to make big patches of plants and are best planted in parts of the landscape where they won't crowd out less vigorous plants. Not recommended for the prime spots in your perennial beds.
- Asclepias incarnata (Swamp Milkweed) is a more refined grower and is fine to include in perennial beds.
Oftentimes, Milkweeds won't grow much their first season in the ground, so be patient. They are establishing their root system and crown. By the second growing season, the plants will begin to get bigger and look more robust. Asclepias species are an odd bunch and don't behave like many other more familiar perennials. So be patient and accept their quirky nature.
- Fertilize Asclepias just once in fall with Yum Yum Mix and Planters II. - Naturalized plantings don't need additional fertilization.
- To encourage re-seeding and provide winter interest with their ornamental seed pods, leave the stems intact over the winter. In mid-spring, remove old stems just above ground level.
- All species of Asclepias are late to emerge in the spring, so don't be concerned if other perennials come up first and they remain dormant.
View more Planting Guides, or download our complete Planting Guide for tips on caring for your plants when you receive your order, as well as planting instructions for Perennials, Spring-Planted Bulbs, Fall-Planted Bulbs, Cacti & Succulents, Xeric Plants and more.
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Q & A
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USDA Hardiness Planting Zones
To determine if a plant is sufficiently cold hardy, the USDA created numbered zones indicating winter low temperatures; the lower the zone number the colder the winter.
- If the coldest winter temperature expected in your area is -15°F (zone 5) then any plants rated zones 3-5 will survive the winter temperatures in your area.
- If you live in very warm winter areas (zones 9-11) plants with zones 3-4 ratings are not recommended. The lack of freezing winter temperatures do not provide a time for winter dormancy (rest).
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