Astrantia: Bare Root Perennial
Planting Bare Root Plants:
- Choose a location in part shade with moist, rich soil.
- Prepare the bed by turning the soil under to a depth of 6-12, inches removing any debris, and lightly raking as level as possible.
- The addition of organic matter (leaf mold, compost, well-rotted manure) benefits all gardens and is essential in recently constructed neighborhoods.
- Dig a hole deep and wide enough to accommodate the bare root.
- Set the plant such that the crown is at or just slightly below the ground level. Allow roots to fan out from the crown at around a 45 degree angle. Roots should spread out separately, like stretched fingers, from the crown, and not bunch up. It may be helpful to build a cone-shaped mound of soil in the bottom of the hole and spread the roots around it. It is important to set the roots such that the crown is roughly level with the ground.
- Cover the roots with soil and tamp down firmly to get rid of air pockets. Fill the soil to just below the crown, where the top growth and leaves will emerge. Make sure all the roots under the crown are in good contact with the soil.
- Water well to fully saturate the roots and soil.
- Wait until new growth starts to appear before applying a layer of mulch.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their germination.
- Mulches also help retain soil moisture and maintain even soil temperatures. For perennials, an organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
- Careful watering is essential in getting perennials off to a good start. Water thoroughly at least once a week to help new roots grow down deeply. Soil should be damp at about 1 inch below the soil surface. You can check this by sticking your finger in the soil. Water early in the morning to give all leaves enough time to dry. One inch of rain or watering per week is recommended for most perennial plants. You can check to see if you need to add water by using a rain gauge.
- Until plants become established, some protection from extreme winds and direct, hot sunlight may be necessary. Good air movement is also important.
- After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer such as Garden-tone, as higher rates may encourage root rots.
- “Deadhead”, remove spent flower heads to encourage continuous flowering and prevent seed development.
- Remove and discard foliage after a hard frost in fall.
- Divide the clumps to keep astrantia under control as these plants spread quickly.
- Many gardeners do not cut back perennial flower seed heads in the fall, but wait until early spring before the new foliage appears. This provides food for wildlife over the winter.
- Astrantia makes a great cut flower, fresh or dried.
- Astrantia will naturalize under trees and also makes a nice addition to perennial borders. It Combines well with ornamental grasses, ferns, astilbes and irises.
Common Disease Problems
Downy Mildew: This fungus causes whitish gray patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Rotate crops with plants in a different family. Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and keeping weeds under control. Contact your Cooperative Extension Service for fungicide recommendations.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Leafminers: These insects bore just under the leaf surface causing irregular serpentine lines. The larvae are yellow cylindrical maggots and the adults are small black and yellow flies. They do not usually kill plants, but disfigure the foliage. Burpee Recommends: Remove affected foliage.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather. Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way full with beer, and let it sit overnight. In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Can I grow astrantia in containers? Yes, it’s great for containers.
Is astrantia a good pollinator plant? Yes, it attracts butterflies.
Do I need to divide astrantia? We recommend dividing every few years to keep it under control.
I have dry shade, will astrantia do well there? Unfortunately astrantia does not like dry conditions, perhaps try it in a container?
How can I use astrantias in my garden? Astrantia looks at home in a cottage garden, naturalized in a woodland, and it’s great for cutting.