Kirengeshoma

( kih - ren - gesh - OH - mah )

At-A-Glance Information

Commonly called Yellow Waxbells, this dainty, elegant perennial grows from rhizome roots. It needs partial shade and regular water to perform well in the garden. Leaves are green and deeply lobed and dark purple stems carry yellow flower clusters at their tips that bloom in late summer and early fall. They are native to Japan and Korea and are great for border gardens and wooded areas. They can be planted amongst ferns or massed under trees as a tall groundcover.

Kirengeshoma species and varietals

The genus Kirengeshoma is a member of the plant family Hydrangeaceae and includes just two species. The genus is closely related to Dutzia, Philadelphus, Hydrangea, Anemopsis, and Carpenteria. Kirengeshoma plants grow best in USDA hardiness zones 5-8 or Sunset growing zones 2-9 and 14-24. To find your zone, click here: Zone Map

Kirengeshoma koreana (Korean Kirengeshoma, Yellow Waxbells)
This species forms a herbaceous plant that has opposite, palmately lobed large leaves. Stems are green, and flowers are yellow, blooming in the middle of summer through early fall. Individual plants reach up to 3-5 feet tall and 2-3 feet wide. They form clumps over time.

Kirengeshoma palmata (Yellow Wax Bells, Japanese Wax Flower)
These plants are native to Japan and eastern China, and form a clump of foliage. Individual plants in the species reach up to between 24 and 47 inches tall and produce pale yellow flowers on slender maroon stems in late summertime. This species does well in USDA hardiness zones 4-8.

Caring for Kirengeshoma

Kirengeshoma plants should be installed in a spot in the landscape that receives partial to full shade. They can handle between 4 and 5 hours of sun during the day, if soil is kept consistently moist. They should be spaced between 1 and 3 feet apart for best coverage and airflow. They can reach up to between 3 and 4.5 feet tall, and do well at the backs of borders or in mixed beds. Ensure that soil is well-draining, moderately fertile, and has a pH of between 6.1 and 7.3 (neutral to slightly acidic). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Water newly planted Yellow Wax Bells regularly to help them develop a strong root system. At maturity, these plants will need their soil to remain consistently moist, and thrive near ponds, in rain gardens, or in bioswale areas. Mulch around the base of plants to suppress weed growth, increase soil moisture retention, and maintain consistent soil temperatures.

Fertilize yearly in early springtime with a application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Do not over-fertilize Yellow Wax Bells, as this can weaken the plant and make it more prone to developing disease or pest issues. The herbaceous foliage of these plants is not frost-tolerant, and plants will typically die back to the ground when frosts come around. Deadhead spent flower heads to encourage reblooms and remove any dead, damaged or diseased foliage as it appears. After foliage dies back, cut plants down to ground level.

Propagation

Kirengeshoma, or Yellow Wax Bells, can be propagated either by division or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Yellow Wax Bells, follow the instructions below:

Propagating Kirengeshoma by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
In either late winter or early springtime, get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 2-6 weeks from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Kirengeshoma by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil, compost and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the rhizome root(s). Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout in the next growing season.

Problems and Pests

Kirengeshoma, or Yellow Wax Bells, are typically resistant to most pests and diseases, though they can suffer from issues with the following from time to time: