Comarostaphylis

( ko - mar - oh - STAF - ih - lis )

At-A-Glance Information

More commonly known as Summer Holly, this formal evergreen shrub is native to coastal Southern California and Baja California. It can reach 6-18 feet tall and 4-8 feet wide. Leaves are leathery, shiny dark green on top and white and hairy underneath, and are 1-3 inches in length. Small, bell-shaped white flowers bloom in springtime, followed by bright red berries (which attract birds). Summer Holly grows well in zones 7-9 and 14-24 (to find your zone, click here: Zone Map). Only one species in the genus (Comarostaphylis diversifolia) is commonly grown as a garden ornamental. The genus Comarostaphylis is a member of the plant family Ericaceae and includes 10 species.

Caring for Comarostaphylis

Plant Summer Holly in a space in the landscape that receives full sun; ideally, they appreciate between 6 and 8 hours of sun each day for the best blooms. When these flowers are grown in less light, they will not flower as profusely. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 6.0 and 8.0 (slightly acidic to slightly alkaline). 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. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish themselves in the landscape. At maturity, these plants are considered drought-tolerant, able to get by on rainwater for most of the year with supplemental waterings during extended periods of dry weather.

Fertilize yearly in early springtime with an 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. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season. More significant prunings should be completed in early springtime before new growth pushes out for the year. Avoid pruning new, young growth, as it produces flowers and fruits. These shrubs are slow growing (putting on about 5 to 10 feet in 5 years), and therefore do not need much in the way of pruning for shape or size.

Propagation

Comarostaphylis 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 Comarostaphylis 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 Summer Holly, 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 Comarostaphylis 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. Soak seeds for 24 hours in lukewarm water (if they are not fresh), dry them, and then put them in an envelope in a sealable container for 90 days in the refrigerator. Both fresh seeds and stored seeds need to be cold-stratified.
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.
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.

Problems and Pests

These shrubs and small trees are not susceptible to the same diseases or pests, and are generally problem-free plantings. For information on commonly-encountered garden pests and diseases, consult the following pages:

Pests & Pest Management

Plant Issues