Silky dogwood (Cornus amomum) is a small deciduous shrub found in wild, wet areas in the eastern United States. The shrub has an unruly growth habit and forms dense thickets when left on its own. It's at its best when used in informal gardens when a manicured look is not needed. It gets its silky name from the hairs on its leaves' underside. It has a moderately fast growth rate—about 1 to 2 feet per year—and reaches between 6 to 12 feet in height and width at maturity.
The benefits of this shrub are its erosion control properties, it attracts butterflies, birds, and bees with its spring flowers and later berries, and it has pretty fall foliage and burgundy-colored winter bark. Silky dogwood grows well in well-drained, moist acidic soil. It can handle all light levels and prefers cool, moist roots in the summer, with a layer of mulch protecting the rootbed.
|Common Name||Silky dogwood|
|Botanical Name||Cornus amomum|
|Mature Size||6-12 feet tall, 6-12 feet wide|
|Sun Exposure||Partial, shade|
|Soil Type||Loamy, moist|
|Hardiness Zones||5-8 (USDA)|
|Native Area||North America|
Silky Dogwood Care
Here are the main care requirements for growing a silky dogwood:
- Prefers partial sun but can tolerate full sun and shade.
- Grows best in moderately wet, well-draining, acidic soil, although can tolerate clay-like soil.
- Handles frosty, wintery weather without requiring protection.
- Cut back suckers to prevent unwanted growth.
- Does not require fertilizer.
- Resists deer, aids in erosion control, and seems immune to juglone (black walnut) toxicity.
The silky dogwood will do best in part sun, although it will tolerate full shade and full sun. You will need to ensure it has plenty of water and that the soil remains moist in full sun positions.
Growing the shrub in slightly acidic soil (pH 5-7) that is well-drained and rich in organics will help it to thrive and have prolific blooms, fruit, and color.
Watering a young plant that is not established is essential. Newly planted shrubs should be watered weekly and deeply for the first year until they have established their roots. Once established, unless there is a drought or it is in a full sun position, the silky dogwood does not require any extra water besides what nature provides.
Temperature and Humidity
Silky dogwoods are found in USDA zones 5-8 and are frost hardy. Where temperatures are high in summer, the shrub benefits from protection from afternoon sun. It does not tolerate drought well.
There is no need to fertilize the silky dogwood. It will grow and spread well on most soils. If the soil is tested for pH and it is high, an amendment can be added to increase the acidity. However, because of its use as a food source for pollinators, fertilizers and amendments are not recommended.
Types of Silky Dogwood
The tree is the host plant for the North American native azure butterfly and three different specialist bee species. The silky dogwood produces plentiful blue drupes or berry-like fruits that attract numerous bird species like the downy woodpecker, thrushes, northern flicker, and northern cardinal. Allowing the shrub to form a thicket will also make a nice nesting area and provide an excellent place for small mammals to shelter.
- C. amomum 'Indigo': Small white flowers and blue fruits
- Cornus obliqua: Commonly mistaken for silky dogwood; slight differences in the silky leaf hairs, grows north of C. amomum
- Red-osier dogwood (Cornus sericea): red-colored branches and berries remain white
Pruning your silky dogwood is vital for keeping the flowering shrub healthy, initiating new growth, producing denser growth, and giving a shrub its shape. It takes a fair bit of management to keep it looking neat and prevent it from becoming too unruly. The best time for heavy pruning is in the dormant season or early spring.
Proactively cut suckers, trim unwanted growth, and remove dead and damaged branches. Mature silky dogwood shrubs typically have four to six main stems. You can prune one of these stems down to ground level without affecting the plant much.
Propagating Silky Dogwood
You can propagate silky dogwood via layering, cutting, and sowing seeds. The best time for propagating is generally in the spring. The fastest methods are layering and cutting. Layering is the easiest; here's how:
A grove can be established if planted in a group to form thickets through rooting. A simple propagation method calls for a stem to be left in contact with the soil and covered or compressed. A rock on a stem would work. After a few months, the stem will have taken root and a thicket formed.
Stem cuttings take more time; here's how:
- You'll need a planting container, rooting medium or sand mixed with perlite, pruners, rooting hormone, and a clear plastic bag.
- Collect stems in the spring. Bend a stem in half; you know it's ready if it snaps when you bend it. Collect several and root them all since the success rate is variable. Cuttings should be 3 to 5 inches long. Cut about an inch below a set of leaves.
- Remove all the bottom leaves and coat rooting hormone on the cut stem end and the leaf nodes where you removed the leaves.
- Fill a clean container with the potting mixture. Tamp it down. Insert the cut stem end into the center of the container.
- Mist the cutting and place the clear plastic bag around the top to create a greenhouse atmosphere. Tent the bag using chopsticks or other implements to ensure the leaves are not touching the bag. Once a week, let in air and check the stem for roots. Gently tug and see if it holds firm. Most rooting occurs within six weeks.
- Remove the bag once rooting occurs. Keep the plant in a sunny window and keep the soil moist constantly. Begin to give half-strength fertilizer to boost growth.
How to Grow Silky Dogwood From Seed
Silky dogwood can be grown from seeds. You can collect the seeds of mature fruits from September to November. Berries have ripened once they turn from white to blue. Remove the pulp. You can direct sow the seeds in the fall or cold-stratify the seeds in the refrigerator for 12 weeks and start the seeds indoors. Here's how to direct sow the seeds outdoors:
- In the fall, sow the seeds 1/4 to 1/2 inch deep in a prepared outdoor bed. Choose a spot that will get shade in the afternoon.
- Mulch over the spot with two to three inches of bark mulch. Mark the location. The mulch must be removed as soon as the ground thaws in the early spring.
- The seeds will need two to three months of cold stratification. Once the temperature and ground warms, the seeds will germinate (temperatures must be between 70 and 85 degrees). Germination can take 14 weeks.
- Once the seedlings emerge, water the soil regularly, keeping the soil moist. Remove any nearby weeds.
Potting and Repotting Silky Dogwood
Dogwoods are not recommended for container growing. Silky dogwood gets large, has a vast, fibrous root system, and needs its roots to remain cool to thrive. Containers are harder to keep cool, especially in the summer.
Silky dogwood is cold hardy down to USDA zone 5, which can survive temperatures dropping to -20 degrees Fahrenheit. It is deciduous, so it drops its leaves in the fall. It goes dormant and, generally, has no problems handling wintery weather.
Common Pests and Plant Diseases
Silky dogwood generally resists insects and diseases. However, like other dogwoods, it occasionally gets scale insects, borers, and leaf miners. Neem oil is a good organic insecticidal method of handling these pests. Silky dogwood is also deer resistant.
Rarely, it can be susceptible to leaf spots, stem or crown canker, blights, root rot, and powdery mildew. Most of these diseases are fungal, occur late in the summer or fall, and usually occur before the trees go dormant; they cause more damage if they occur early in the season. Fungicide should be applied if noticeable in the spring.
How to Get Silky Dogwood to Bloom
If your silky dogwood is not blooming, ensure you're not using fertilizer, especially a high-nitrogen formulation on or near the shrub. Nitrogen often reduces flower production in favor of leaf production. Also, a lack of water or the wrong soil can affect flowering.
Silky dogwood blooms in May and June.
How Long Does Silky Dogwood Stay in Bloom?
Silky dogwoods flowers remain in bloom for about 10 to 14 days.
What Do Silky Dogwood Flowers Look and Smell Like?
Silky dogwood produces tiny, creamy-white 2- to 3-inch flower clusters. Each flower is about 1/2 inch wide with four star-looking petals. The flowers have a sweet fragrance similar to honeysuckle.
Common Problems With Silky Dogwood
Silky dogwood is fairly disease and pest resistant; however, it will suffer from environmental conditions, such as mower injury, over-fertilization, or poor growing conditions.
Browning Leaf Edges
Leaves with noticeable browning of leaf edges or between the veins can indicate overly dry conditions. Dogwoods need adequate moisture to thrive since they have a shallow root system and are susceptible to drought stress. Give water deeply and regularly, especially if the tree is in a full sun spot. Also, layer mulch over the root zone to help the soil retain moisture.
Leaves Turning Red
If leaves appear to be turning red well before the fall foliage season (for instance, in summer), the plant is in distress. It can be a sign of powdery mildew or crown canker, or it could be drought stress or too much sun. Give water to help alleviate drought stress.
How is silky dogwood helpful for erosion control?
The silky dogwood shrub is often used as an effective method for stabilizing slopes and streambank erosion. Combining the silky dogwood with other plants, such as willows, as a canopy alongside grasses at ground level can help manage erosion nicely.
How is silky dogwood used in landscaping?
One of the silky dogwood’s niches is its ornamental uses. While its summer foliage is not impressive, the spring flowers, fall color, and exciting winter bark and twigs make this small tree attractive throughout the year. It can be used in a cottage-style garden or as an accent shrub in a rain garden to provide three-season interest.
How fast does silky dogwood grow?
Silky dogwood grows at a medium growth rate, averaging 12 to 24 inches annually.
How big does silky dogwood get?
On average, silky dogwood gets about 10 feet tall. Although, on the small side, it grows about 6 feet tall. In great growing conditions, it can get up to 12 feet tall.