Astilbe Planting Guide

Gardeners with lots of shade discover early on that the list of visually impactful options is limited. Allow us to introduce astilbes, your new friend. These plants thrive as foundation color on the north (shady) side of your house or garage, or under the canopies of deciduous trees. Astilbes also provide fluffy filler color for flower arrangements, material you're unlikely to find at any floral supply shop. As a bonus, astilbe flowers also attract butterflies and support pollinators like honeybees.

Choosing a Site for Astilbes

Astilbes prefer some shade and are happy with a range of light from dabbled sunlight to moderately shady to the shade that’s found on the north side of buildings. (Sorry, nothing’s going to grow robustly in the dense dark shade under that giant blue spruce.) Astilbes are more tolerant of clay soils than are most perennials plants.

Soil Prep

Light to moderate feeders, astilbes grow well in average, well-drained soil and don’t require rich, perfect loam. Compost, dug in when planting or added as a top dressing later, provides a welcome supply of nutrients. Keep in mind that composts' NPK (nitrogen, phosphorus, potassium) ratio vary greatly product to product. Don't assume that adding more is better.

When to Plant Astilbes

Plant outdoors when frost danger has past. Astilbes are hardy perennials and can take freezing without ill effects once they are established but are susceptible to frost damage prior to settling in. For fall planting, get your astilbes in the ground at least 6 weeks before hard frosts typically arrive in your region. This gives the plants time to develop sufficient roots before going into winter and helps avoid frost heave.

How to Plant Dormant Bareroot Astilbes

Your astilbes will be shipped bareroot, in a dormant state. Dormancy means the plant is not in actively growing; it’s been held in a cool, dark setting similar to winter garden conditions and is “sleeping”. The bareroot term means that the soil has been washed from the roots; there is no risk of introducing any soil-borne diseases into your garden, and the plants are lighter and cleaner to ship. When you plant your astilbe, adding light and moisture, they’ll wake up. Roots will start growing in a few days and top growth will be visible in 1-3 weeks. Fall planted astilbes will develop roots in the cool, but not frozen, soil and sprout top growth in spring.

Dig a hole a bit bigger than the root ball and mix in a couple scoops of compost. Fan out the roots in your planting hole and place the crown (area from which leaves will sprout) an inch below soil level. Refill around plant with soil, tap down to eliminate any big air pockets and water well.

In the garden, space your plants so they have enough room to grow without crowding. Allow 18-24” between plants for full size astilbe and 14-18” for the more compact Younique astilbes.

During the Growing Season

Astilbes require little care during the growing season. During their first season, while they are settling in, make sure they receive 1-2” of water, from rain or irrigation, per week. From their second season on, they’ll be fine with about the same or a little less. Feel free to snip flowers; this won’t hurt the plants. Or leave the flowers to develop into seed heads and cut these for fall arrangements.

Insider Tips

  1. Deer and rabbits tend to avoid astilbes. If hungry deer and/or rabbits are a problem in your area, astilbes could be the perfect solution.
  2. Astilbes will tolerate soil that’s on the moist side. If part of your yard has less than perfect drainage and is shady, astilbes could be worth a try. Cool, moist summers are ideal for astilbes.
  3. Where happy, astilbes will readily grow into sizeable clumps. Divide every 3 to 4 years by lifting in the spring when you see new growth and pulling/cutting apart sections. Replant the new astilbes at soil level and water to settle in. Or share with friends!
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Success Snapshot

Light: Light to moderate shade

Soil: Fertile and well drained

Depth: Plant clumps at ground level

Water: Average moisture

Uses: Beds, accents and woodland gardens

Tip: Use where deer and rabbits are a problem

GUIDE: Astilbe Planting Guide

They Start Out Looking Like This: