Learn About Cleomes
How to Sow
Sowing Cleomes Directly in the Garden:
- Direct sow Cleome seeds in average soil in full sun after danger of frost.
- Prepare the soil for Cleomes by removing weeds and working organic matter into the top 6-8 inches of soil; then level and smooth.
- Most annual flower plants respond well to soils amended with organic matter. Compost is a wonderful form of organic matter with a good balance of nutrients and an ideal pH level, it can be added to your planting area at any time. If compost is not available, top dress the soil after planting with 1-2 inches of organic mulch, which will begin to breakdown into compost. After the growing season, a soil test will indicate what soil amendments are needed for the following season.
- Sow seeds thinly and cover with ¼ inch of soil.
- Firm soil lightly and keep evenly moist.
- Seedlings will emerge in 14-21 days.
How to Direct Sow Cleome Seeds
How to Grow
- Thin Cleome flower plants to stand 8 inches apart when plants are 1 to 2 inches high. Thin again to 2 feet apart when plants are established.
- Keep weeds under control during the Cleome growing season. Weeds compete with annual flower plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating.
- Mulches also help retain soil moisture and maintain even soil temperatures. For annuals an organic mulch of shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
- Keep soil evenly moist but not wet. Fertilize as needed with a slow release fertilizer designed for flowering plants.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
- Plants can self-sow, so allow some to set seeds.
- Remove plants after they are killed by heavy frost in fall to avoid disease issues the following year.
- Cleome annual flowers are easy to grow and need little care.
- Cleomes make striking, fast-growing annual hedges. Their thorns and dense foliage create an effective barrier, while prolific blooms create a pleasing mass of color.
- Add tall varieties to the back of an annual, perennial or mixed border for their long bloom periods and airy flower heads. You can use them to fill in between clumps of perennials, and they combine well with many shrubs.
- Cleomes also make interesting cut flowers.
Common Pests and Problems
Alternaria Leaf Spot: Small, round reddish brown spots with white to gray centers form on the upper surface of the leaves and along the midrib. The lesions may encircle the stems and cause wilt. This disease is worse in warm, wet or very humid weather. Burpee Recommends: Avoid getting water on the foliage. Remove infected plant parts and do not work around wet plants. Provide plenty of air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation.
Downy Mildew: This fungus causes whitish grey patches on the undersides and eventually both sides of the leaves. Burpee Recommends: Avoid overhead watering. Provide adequate air circulation, do not overcrowd plants. Do not work around plants when they are wet.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Rust: A number of fungus diseases that rust colored spots on foliage and stalks. Burpee Recommends: Remove infected plants. Contact your Cooperative Extension Service for recommendations.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps which feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Edema (Oedema): Leaves become distorted due to excess moisture in the soil. Plants absorb more water than they can use. Burpee Recommends: Do not overwater plants, keep the soil moist but not wet. If drainage is poor add compost or peat moss to improve drainage.
Harlequin Bug: A flat, shield-shaped insect up to 3/8 inch long. The bug is black with red, orange or yellow stripes. Eggs are tiny white barrel shapes with black stripes and are found on the back of leaves. Nymphs are yellow to orange with black stripes. Harlequin bugs suck the juices out of the leaves, causing white or yellow blotches to appear. Leaves can turn brown and wilt. Burpee Recommends: Search for and destroy the egg masses on the back of leaves. Handpick and destroy adults and nymphs. Check with your Cooperative Extension Service for insecticide recommendations for your area.
Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.
Whitefly: These are small white flying insects that often rise up in a cloud when plants are disturbed or brushed against. Burpee Recommends: They are difficult to control without chemicals. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for pesticide recommendations.
Can I start seeds inside? Cleome is very easy to start outside and does not need to be started inside, however you can start them inside 4-6 weeks before the last frost.
Does cleome attract any beneficial insects to my garden? Yes, cleome attracts bees and butterflies to the garden.
Why are my plants shorter with smaller flowers? Be careful that the plants are spaced properly as plants that are too close together can have smaller flowers.
Where should I plant my cleome? Cleome should be planted in mass at the back of the garden. It is best to plant something in front to cover any bare stems that may occur.
Do cleome plants need to be staked? Unless they are in a very windy spot cleome does not need to be staked as the plants can support each other.