Skimmia

skimmia

( SKIM - ee - uh )

At-A-Glance Information

The genus Skimmia is commonly known as Japanese Skimmia. Plants in the genus are native to Japan, China, Taiwan, the Himalayas and Southeast Asia, preferring warm temperate climates. They reach up to between 2 and 5 feet tall and 3 and 6 feet wide at maturity and need regular water and partial shade to perform well in the garden. Leaves are glossy and green and lightly scented flowers are white, opening from pink-red buds. In fall and winter, female plants will produce red berries if a male plant is nearby for pollination. Use Skimmia shrubs as foundation plants, hedges, or mass plantings. They do well in containers on patios, and can also be used in mixed beds and borders to fill empty spaces and add structure. Take care when planting these shrubs in the landscape, as all plant parts are toxic (especially the berries) to humans and pets if ingested.

Skimmia Species and Varietals

The genus Skimmia is a member of the plant family Rutaceae and includes four species. The plants in this genus are related to those in Citrus, Boronia, Ruta (Rue) and Zanthoxylum (Prickly Ash). Skimmia shrubs grow well in USDA hardiness zones 6-9 or Sunset growing zones 4-9 and 14-22. To find your zone, click here: Zone Map.

Skimmia x confusa (Hybrid Japanese Skimmia)
This species has strongly scented foliage and reaches up to 2 to 10 feet tall when mature. Leaves are glossy and green, and flowers are cream to light yellow, blooming in large pyramidal clusters in springtime. These plants are the result of a cross between S. anquetilia and S. japonica var. japonica. The two main cultivars of this species are 'Kew Green' (male with massive clusters of heavily scented cream flowers to 3-5 feet tall) and 'Isabella' (female with spicy lemon scented leaves, white flowers, and red berries.

Skimmia japonica (Japanese Skimmia)
This species is commonly grown in parks and gardens for its ornamental value. It produces beautiful green glossy foliage and large inflorescences of white flowers. Blooms are fragrant and followed by red berries. Variety Skimmia japonica reevesiana is a dwarf selection reaching 1.5-2 feet tall and 2-3 feet wide; it is self-fruiting and has dull crimson-colored berries. Cultivars of this species are listed and described below:

'Bronze Knight'
With glossy bronze-tinted leaves. Male. 3-5 ft.

'Finchy'
With cream to lime green flower buds. Male. 24-30 in.

'Fragrans' ('Fragrant Cloud')
With exceptionally fragrant white flowers. Male.

'Fructo Alba' ('Fructu Albo')
Compact shrub with glossy white berries. Female.

'Godries Dwarf'
Male, compact with pink flowers buds.

'Kew White'
Female with creamy white berries and flowers.

'Mystic Marlot'
With silver-variegated foliage.

'Nymans'
Free-fruiting female clone with abundant berries.

'Obsession'
Long-lasting vibrant red fruit clusters. Female.

'Pabella'
Heavy crops of winter berries. Female.

'Redruth'
Self-fertile. Foliage is variegated.

'Rubella'
Male with dark mauve-red buds and white flowers.

'Temptation'
Female compact shrubs with strong berry production.

'Veitchii'
Reilable female with good berry crops.

Caring for skimmia

Plant your Skimmia shrub in partial shade to full shade. The ideal planting site is a place that gets morning sun with afternoon filtered shade is ideal, but these shrubs can tolerate more shade than many others. Japanese Skimmia shrubs prefer soil to have a pH of between 5.6 and 6.0. Amend soil with plenty of organic matter before planting, and ensure that soil is well-draining. Keep soil consistently moist, especially during the flowering and fruiting season. Mulch around the base of the plant to increase soil moisture retention.

Fertilize with a balanced, slow-release fertilizer at half-strength in springtime. Avoid over-feeding these shrubs, as this can lead to excessive foliage growth at the expense of flowering. Pruning these shrubs is relatively straightforward. The best time to prune is in late springtime or early summer, when the shrub can be trimmed to shape and remove dead or damaged foliage or branches. If you are pruning to increase berry production, leave female plants unpruned to encourage berry formation, and prune male plants lightly in springtime (excessive growth can impede pollen production).

Caring for Skimmia in Containers
Skimmia shrubs do very well in the ground, but can also be grown in containers. The best cultivars for container cultivation are compact varieties such as 'Rubella', 'Temptation', 'Magic Marlot', 'Godrie's Dwarf' and 'Fragrans' ('Fragrant Cloud'). Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Skimmia plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

Skimmia shrubs can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting 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 shrub, follow the instructions below:

Propagating Skimmia by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings 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.
In spring or early summertime, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 6 inch portion(s) of the end of a non-blooming branch and strip the leaves off of the lower half. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot. Fill in soil around the cutting to support it, but do not pack it down too much.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in warm, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth on your propagated Abutilon, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage your new shrub.

Propagating Skimmia 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 pods 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 begin 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.
Skimmia japonica seeds have a hard coating that protects them, but this coating also makes it a little difficult to get them to germinate. We can help the process along by soaking the seeds in warm water for 24 hours to help soften the seed coat. Do this with as many seeds as you can; they will probably not all sow, and the ones that do will be of varying characteristics. The more seeds you plant, the more chances you will have to get the resulting shrub you want.
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 7-14 days 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 55 and 70 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.