Why is it that every time I think of shade gardens, the first plant that comes to my mind is a hosta? Could it be that everyone just really loves the large foliage, and the many different cultivars to choose from? I personally find it difficult to think of many plants that will add BRIGHT colors to the shade garden to liven the place up. Yes, the flowers of the hosta can be very beautiful, but I want something bigger and bolder. Looking around the gardens on a cloudy day, the astilbes are what really catch my attention in the shade gardens.
Astilbe, also known as False Spirea, is a moisture loving shade plant. Astilbes prefer to have organic rich soils (as does everyone else) with plenty of shade. Having soils with higher clay content isn’t all bad since it can hold a little extra moisture for our astilbe friends. However, be sure to keep an eye out for those hot dry summer days. One of the most common issues with astilbes is dryness. I’m sure many noticed during the 2013 summer drought that the astilbes had brown margins on the leaves, or even whole leaves that withered up and died prematurely. Having an ample amount of moisture is essential to having healthy astilbes. Other than the inability to tolerate drought, there are few insects and diseases that really affect astilbes.
What makes the astilbe such a special plant to use in the shade garden? The large plume-like flowers are what really distinguish the astilbe from other shade plants. Long slender stems rise up from the mound of finely toothed leaves to show off large colorful flowers. With the many different cultivars you could have a simple white or cream colored flower to a brilliantly bright pink or red flower. Depending on the cultivar, there are astilbes that flower as early as late spring, and there are others that flower late summer.
As summer progresses into fall, the flowers will start to fade. The dried up flower panicles give a little extra texture and interest to the garden. If keeping the flower panicles attached isn’t something you are particularly fond of, they can be cut off and the foliage of the astilbe will make a decent groundcover. Some cultivars may even have a reddish tint to the foliage so there is still a little extra color to be displayed. If you are like me and have difficulties keeping rabbits and deer from chewing your hostas down to nothing, the astilbe is a great addition to any shade garden.
Some great examples of beautiful astilbes can be found all over the IMA grounds. The border gardens have beautiful plantings of astilbe ‘Amethyst’ as well as A. x rosea ‘Peach Blossom’. The formal garden is home to a few A. x arensii ‘Erica’. There are also quite a few astilbes that are right next to the parking lot across from the Garden for Everyone. These are most certainly not the only astilbes that can be found on the grounds, so feel free to explore and find some more.