Yellow Wax Bells: The belle of the late summer garden

Yellow Wax Bells, Kirengeshoma palmata, are a little known but dramatic herbaceous perennial for the full to partial shade garden.  A late summer bloomer, its striking clusters of pendulous bright yellow flowers bloom when just about nothing else does, making it a favorite of gardeners in the know.  This exotic-looking perennial is a great addition to the woodland garden and can be planted under high trees.   Good companion plants include ferns, hostas, astilbe.  It can also be grown in a container. As I get older and travel more, I have planted more and more perennials in planters as they are lower maintenance and return year after year.

The flowers emerge in tight spherical buds and will open in 1-2 weeks after appearing. You can see some buds are tighter than others, leading to sequential opening and an extended blooming period.

This native to the mountainous regions of Japan and Korea is a member of the hydrangea family.  It is hardy in zones 4 to 8.  Its name comes from the Japanese, ki (yellow), renge (lotus blossom), shoma (hat).  Kirengeshoma palmata was the winner of the 1993 Royal Horticultural Award of Garden Merit.  I have grown it in our zone 6 garden for 17 years and it never fails to attract attention from visiting fellow gardeners who want to know, “What is this?”.

Plant Yellow Wax Bells in well drained soil in a shade to part shade location where the plant will have at least 4 feet of space to spread into its clump-like mounded shrub form.  Water regularly until established then only in severe dry periods.  The plant will establish quickly and is pretty much resistant to most insects and resistant to deer.  Slugs can be a problem for the young leaves. The 1.5 inch  bright yellow flowers will appear in clusters in late July-early August.  They slowly open from tight, spherical buds into bell-shaped pendulous flowers with pointed tips turned outwards and flower for several weeks.  The flowers attract butterflies and can be cut for arranging in bouquets. The flowers are followed by funky-looking seed pods with intriguing 3-pronged seed capsules that go from green to brown when mature. If the foliage is not damaged by frost, it will turn a gorgeous golden color in fall.  After the first freeze or in late autumn, cut the stems back to the ground, although I often just leave mine to decompose on its own.

Propagation is best done in the spring by division.  Just as spring growth begins, separate  large clumps with at least 3 buds in each division.  Water until established.  Yellow Wax Bells can also be grown from seeds although I have never tried it.  Select nurseries sell it in small containers for spring planting.

The stems are almost woody, eliminating the need for staking the 3 to 4 feet tall plant.

The  darling of the late summer woodland garden.

The striking maple-shaped leaves make it an interesting 3-season plant. The leaves can be bright chartreuse as these are in part shade or a deep green in deeper shade.

Yellow Wax Bells are grown as much for its dramatic foliage as for its flowers. The leaves can be up to 8 inches in diameter and feature an almost felt-like surface texture. Late in the season, before the first frost, the leaves will turn gold.

The handsome dark stems create a dramatic contrast to the bright yellow flowers.

The shrub-like habit of the clump forming plant which can grow 4 feet high and 4 feet wide.

As my friend Bonnie put it best, yellow wax bells are just the pick-me-up tired summer gardens need!

Sources:

Monrovia.com, WImastergardener.org, missouribotanicalgarden.org