Companion Plants for Astilbe | Growing a Diverse Shade Garden

Astilbe is a unique herbaceous perennial with fuzzy flower spikes and fern-like foliage. Its primary role in the garden is to add ornamental interest to shady areas and maybe attract a few extra pollinators. 

Due to most varieties’ small size, astilbe is rarely used as a specimen planting. But it does great work as the co-star of larger, more attention-grabbing performers. For this reason, I like to use astilbe in the midground of the garden, just behind the lower groundcovers.

If you want to incorporate this plant into your landscape or are looking for ways to make existing plants more impactful, the first step is to narrow down the best pairing partners. In this article, I’ve listed some great companion plants for astilbe and how to use them. 

Companion Planting 101

Companion planting is an approach to designing your garden so that the different plants benefit each other as much as possible. Just like people, plants are usually happier when they have good neighbours!

Instead of just placing plants randomly, you want to think about each plant’s needs and how they might interact with those of neighbouring plants. For example, some plants will grow better in the shade of taller ones. 

Good companion plants can share resources like sunlight, water, and nutrients without creating competition. They may also work together to attract beneficial wildlife while keeping unwelcome pests away.

Companion planting takes a bit more planning and knowledge, but it’s worth it because it can help create a healthier and more balanced (and more attractive!) garden.

Advantages of Using Companion Plants

It makes your garden look better. Most gardeners can agree that good landscape design requires using more than one type of plant. As a result, aesthetics are a natural benefit of companion planting.

It maximizes your available space. You can fit a whole lot more plants into a garden just by diversifying what you grow. This is achieved by mixing plants with varying growth habits — e.g., groundcovers and shrubs — and needs. Meanwhile, growing dozens of the same plant will lead to an imbalance of resources and increased competition. 

It draws more beneficial wildlife to your garden. A range of foliage types and plant sizes can increase biodiversity in the form of insects, birds, and other wildlife. Planting flowers that bloom at different times of the year will increase pollinator activity and indirectly control pests by attracting beneficial predatory insects like wasps and hoverflies.

It can improve the soil quality. Growing a diverse selection of plants can help insulate the soil, preventing weeds from sprouting and retaining valuable moisture and nutrients. 

It creates a self-sufficient landscape. As I touched on above, sometimes larger plantings can be used to provide shade or structure for other plants. This can expand the types of plants that will grow in your garden space without needing to rely on trellises or artificial shade. 

Best Companion Plants For Astilbe

While some plants love the sun, astilbe loves shady, moist spots. This makes it a great plant for filling in those cool areas where other plants might not do so well. This plant’s love of damp soil also makes it ideal for use around ponds and other water features.

astilbe near pond

Astilbe typically blooms for several weeks at a time. Varieties are categorized based on bloom time, so you can hypothetically mix and match different astilbe plants for flowers that last all season.

The plant’s unique leaves also help it stand out from other perennials. I find the foliage to be quite attractive even before the astilbe starts blooming. I’ve also heard that the fern-like leaves are preferred by some beneficial insects for use as shelter.

Astilbe obviously has a lot to offer gardeners on its own. But, for the best results, you should also try including some of these companions in your shaded landscape project.

Foliage and Groundcover

Fern: Shade-tolerant ferns go together with astilbe like peanut butter and jelly. The moist soil conditions favoured by astilbe also suit most ferns, and the combination of the two is perfect for a relaxed woodland-style garden bed.

Hosta: Hostas boast big, lush foliage that contrasts nicely against the more delicate leaves of astilbe. Both plants enjoy similar conditions; i.e., partial shade and moist soil. I like to use astilbe to fill the gaps between larger hostas.

astilbe and hosta

Sweet Woodruff: This is a ground cover well-suited to full-shade areas, especially under mature trees. Over time, it creates a green carpet dotted with white flowers in the spring. You can use astilbe to break up the sea of sweet woodruff and increase biodiversity.

Periwinkle: Also known as myrtle, periwinkle has a low, spreading growth habit and glossy, evergreen leaves. It’s an attractive option to quickly fill in around large trees or shrubs but will rarely choke out other plantings.

Pachysandra: Pachysandra, also called Japanese spurge, is another low-growing plant that has become a popular groundcover in recent years. It usually grows less than 12 inches tall, so your astilbe will happily tower over the evergreen foliage.

Creeping Dogwood: If you’re trying to naturalize a woodland garden, this charming groundcover should definitely be on your wishlist. Some people know this subshrub as bunchberry but it belongs to the same genus as dogwood trees. It’s native to North America and is an excellent partner for astilbe and other shade lovers.

White Wood Aster: This herbaceous perennial is found growing natively on many North American forest floors. It’s unique from most other shady groundcovers because it blooms in later summer and falls instead of spring, making it a valuable food source for local pollinators.

Herbaceous Perennials

Wild Geranium: Wild geranium (Geranium maculatum) tolerates shade a bit better than other types of hardy geranium, a.k.a. cranesbill. It’s very easy to grow alongside astilbe and, according to the University of Wisconsin, is a great food source for native pollinators like the uber-beneficial hoverfly.

Columbine: This spring ephemeral is a really nice addition to any woodland garden design. Both native and cultivated varieties are available depending on your location. Just double-check your chosen Columbine’s tolerance for shade, as some require full sun.

Coral Bells: With their compact growth habit, assorted foliage colours, and pollinator-friendly flowers, coral bells work extremely well in the same landscape applications as astilbe. In fact, the two plants are close relatives!

Virginia Bluebells: This native woodland wildflower pops up for just a few weeks in mid-spring. Virginia bluebells can be used to add colour to the garden in the time before your astilbe blooms.

Yarrow: Yarrow can typically handle more sun and less moisture than astilbe. If planted in a location that meets the needs of both, however, yarrow is an aesthetically pleasing companion known to draw in beneficial insects.

Woodland Phlox: Phlox divaricata is a short ground cover that produces star-shaped flowers akin to those of creeping phlox. I recommend this species in particular for shaded gardens because of its low sun requirements.

Goldenrod: While many gardeners view goldenrod as a weed, it is frequently listed as one of the most vital wildflowers for North American pollinators. Check your local plant nursery for ornamental cultivars that suit your gardening needs.

Penstemon: I personally think Penstemon looks a bit like a cross between a snapdragon and salvia. Though it has little relation to either one, penstemon is a great pollinator-friendly perennial that can stand up to some of the toughest growing conditions.

Foxglove: Usually available as either a biennial or a herbaceous perennial, foxglove is one of the few non-shrubs that can be placed in the back of a garden bed. Foxglove’s tall spires of bell-shaped flowers provide contrast to astilbe and other shade-tolerant plants.

Aster: Several varieties of asters will tolerate shady conditions but some may not produce as many flowers. Even with fewer blooms, I find asters to be one of the best solutions for late-season colour in the garden.

Siberian Iris: Though not as showy as the bearded iris, this clump-forming perennial will happily grow in partial shade and a wide range of soil qualities. Mine bloom shortly after my bearded irises and about the same time as my earliest astilbe.

Trillium: Trillium is an interesting North American wildflower that is protected throughout much of its natural range. However, some nurseries propagate trilliums for use in the home garden. These spring ephemerals work particularly well in beds shaded by large trees.

Shrubs and Trees

Azalea and Rhododendron: These hardy shrubs can grow in anything from full sun to part shade. All azaleas and rhododendrons tend to flower in the spring before the astilbe. For all-season interests, I recommend planting an evergreen variety.

Hydrangea: Hydrangeas are some of the most popular shrubs for shaded gardens. Most varieties prefer a cool spot that receives several hours of shade in the afternoon. Try using Oakleaf Hydrangea companion plants as a backdrop for your astilbe bed.

astilbe and hydrangea

Forsythia: Forsythia blooms early in the spring with bright yellow flowers, providing a cheery pop of colour when many other perennials are just starting to wake up. It will thrive almost anywhere that receives at least 4 hours of sun per day.

Flowering Dogwood: This understory tree offers year-round interest with flowers in the spring, berries in the summer, and multi-coloured leaves in the fall. It prefers similar shady conditions to astilbe.

Japanese Andromeda: Japanese Andromeda is an evergreen shrub that blooms in very early spring. In some areas, this plant begins flowering while there is still some snow on the ground. Note that Japanese Andromeda is toxic if ingested.

What Not to Grow with Astilbe

Aside from false goatsbeard (Astilbe biternata), astilbe are non-native throughout most of the world. Yet they are still incredibly popular in native pollinator gardens in North America and abroad. 

garden with native and non-native astilbe

There are a few risks to including astilbe in your own native-inspired garden. Just be aware that popular perennials like rudbeckia, coneflowers, and coreopsis generally need a lot more sun than astilbe.

If you still have your heart set on growing these flowers together, look for ways to design the garden so that the astilbe remains in the shade for most of the day.

For similar reasons, herbs and ornamentals that prefer dry growing conditions will struggle to thrive alongside astilbe. Some examples that you’ll want to plant in a fast-draining part of the garden include lavender, sage, and stonecrop.

Though few plants will directly compete with astilbe for resources, think twice about planting astilbe under vigorous trees like maples or birches

This might seem counterintuitive since large trees provide the shade astilbe crave. However, the roots of these trees can make it difficult for astilbe to access enough water and nutrients from the soil. 

Citations

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Ben's horticultural interest grew when graduating from Hertfordshire University in 1997. Having contributed to numerous publications including Better Homes & Gardens, Garden Design Magazine, and The English Garden. He is also the author of Propagating Houseplants Made Easy.