Astilbe-A Perennial To Plant In Fall

October 2, 2021

Steeples and Spires For The Shade Garden

If you make gardens; you love to look at them. When you cast your eye across a beautiful landscape there are always some plants that make you stop.

In the shade garden, we have a lot of choices of mounding and low plants. Astilbe, conversely, bloom in graceful spires and brilliant colors. They are eye-catchers in the shade garden. They are a perfect replacement for nonperforming turf in shady areas or as enhancements in the shaded wild edges of the backyard.

Astilbe-A Table Of Essential Features

Astilbe is desirable to plant in spring, after the last frost date, and also in the fall garden before frost begins. It is featured in the post on this site “In Fall-Invest In The Garden” because it is one of the valuable perennial plants to prepare in fall and get an early start on next summer’s blooms.

The following table will help you quickly decide if this beauty will grow in your garden. Look, especially, for your plant hardiness zone, Light and soil conditions. If those can be accomodated in your garden, check the other features to see if Astilbe is for you.

HEADINGSINFORMATION
Plant Name, CommonSalvia
Plant Name, BotanicalVarious
Significant AttributesColorful spikes of densely packed tubular flowers
ColorBlue, purple, red, pink, white, yellow.
Scentaromatic
Bloom PeriodMidsummer on. In warm zones all year.
Hardiness Zones4-10
Light RequirementsFull sun.
Soil RequirementsWell-drained, with compost, light, fertile, loamy, moist but with drainage. Never wet.
Soil pHNeutral to slightly alkaline
Water RequirementsWater in AM. Regular water in summer, do not allow plants to stand in soggy soil in winter
Plant TypePerennial, and annual versions. For zone 10 annuals last several years.
Garden UsageBeds. borders, containers, cottage garden, cut flowers.
Size18:-5′. Check varieties
Planting Distance18-24″ apart.
Pollinators and WildlifeYes
Cautionsvery few pests and diseases.

Varieties of Astilbe

Astilbe come in a considerable range of size, from 6″-to 5′! Please note that as a popular plant, you can expect new varieties each year. Look for some of the newer offerings to include more interesting foliage colors and textures. Astilbe foliage is attractive on its own and this extends the beauty of the plant in the garden.

Because the range is so broad and limits their usability in each of our gardens I will sort the varieties into size ranges. In each case, I will provide, name, color, and height as well as other pertinent information. Here are the groups:

  • Dwarf
  • Medium
  • Tall

Dwarf Varileties of Astilbe

  • Cotton Candy- pink, blooms midseason 16″ tall
  • Delft Lace-apricot-pink,blue-green foliage, 16″
  • Hennie Graafland-(more vigorous alternative to Sprite), pale pink, 14″
  • Pumilla-lavender blooms late season 1′
  • Pereko-rose, mid-late summer 6-12″
  • Sprite-pastel pink, blooms midseason, 1′
  • Vision lavender-compact, reliable, short foliage, early bloom, 12-18″

Midsized Varieties of Astilbe

  • America-lilac rose, 28″
  • Chocolate Shogun-pale pink flowers, chocolate foliage (grown primarily for foliage) midseason, 20-24″
  • Deutchland-white, early blooms, 28″
  • Fanal-deep burgundy blooms mid-June,2′, bred by the leading developer George Arends
  • Elizabeth-lavender-rose,blooms mid-season, 28″ high
  • Montgomery-magenta-red, bronze-red foliage, midseason, 22″
  • Veronica Klosdale-purple-rose, 2′

Tall Varieties of Astilbe

  • Ostrich Plume-salmon-pink, midseason, 40″
  • Prof, Van Der Wielen-white, midseason, 40″
  • Purple Candle-red-purple, Late season blooms, 42″
  • Purple Lance-pink-purple, late August-September, 40″
  • Red Sentinel pinkish-red-mid season, 3′

Growing Astilbe

How To Plant Astilbe

Astilbe will thrive in consistently moist, humus rich soil. It will not accept dry soil or soil which is soaked.

Plant with the roots slightly fanned and pointed downward. Place the crown of the plant one to two inches below the soil and press soil down. Follow the shade instructions for your variety of astilbe. Some accept morning sun and varieties of shade.

Water And Fertilizer For Astilbe

Astilbe have simple but specific requriements. Never dry or wet but always moist. They grow naturally near ponds and streams.

Astilbe require phosphorus to bloom. Use fertilizer rated 5-10-5 or 10-10-10 and rake the fertilizer into the soil about two weeks before planting. Once astilbe are established, fertilize every spring while the soil is damp.

Ongoing Maintenance

Divide the plants every 4-5 years for best plant health and to increase your supply. If your plants have ideal growing conditions you may divide sooner.

Uses Of Astilbe

Astilbe is a way to extend the garden to its margins and enhancing shaded areas. It is also a desirable cut flower and can be dried. The dwarf varieties are ideal additions to the shaded container garden.

Pests And Diseases Of Astilbe

Pests

Astilbe are pest resistant but if attacked these are the most likely pests with identification and treatment information.

Aphids

Aphids are tiny soft bodied insects which suck the nutrition from plant foliage. They come in various colors often appearing white or green tiny dots on the underside of leaves. It is best to be observent and always checking the underside of leaves as you work or view your garden.

Treat them with sprays of water, with mild liquid soaps, insecticidal soaps and by removing affected leaves.

Leafhoppers

Leafhoppers inject toxins into the plant leaves. This damage appears as a burned appearance on the edge of the leaf. You may also see yellow/green bodies. Treatment is similar to aphids. Use blasts of the hose, remove affected leaves, use mild soap, and insecticidal soaps. There are also yellow sticky traps, do not leave these out indefinitely as they also trap beneficial insects.

Spider Mites

Spider mites are tiny, the adults are reddish-brown in color, they live in colonies on the underside of the leaves and feed by piercing the foliage. They are an arachnid, not a true insect. Treat with predators such as ladybugs, neem oil or insecticidal soaps./

Whiteflies

Whiteflies are sucking insects feeding on the sap of the plant. Look for a white, powdery film on the foliage. Treatment includes beneficial insects such as ladybugs, or parasitic wasps. The best defense is clean growing conditions, sterilized tools, and removal of any damaged or diseased plant material.

Diseases

Leaf Scorch

In Leaf scorch the margins of the leaves turn reddish brown, similar to the damage of leafhoppers. However in this case the damage is accomanied by hot and windy conditions and dry soil. If needed, move the plants to a more damp and shady location.

Leaf Spot

Leaf Spot-is indicated by well defined dead spots on the leaves, this sometimes extends and covers the entire leaf. Try to water the soil and not the foliage.

Powdery Mildew

Powdery Mildew-look for white, powdery areas on the foliage. This is a fungal growth, treat with a fungicide.

Root Knot Nematode

Root Knot Nematode-galls develop on the roots and the plant may appear stunted. Remove all affected plant material and leave the immediate area unplanted for one growing season.

Virus

Virus-Plants are yellow but roots appear healthy. Remove the plants.

Wilt

Wilt-the plants have broken, sunken, dead areas on the stem near the root line. The plants appear, generally wilted. Remove the plants.

Summary,

Astilbe are hardy, herbaceous perennials treasured for large and handsome foliage, often fern-like in nature and tall plumes of blooms. There are eighteen species.

The plant is native to both eastern Asia and North America. Most of the original plants were discovered in mountain areas of both China and Japan.