It’s possible that cleomes’ lack of popularity comes from the fact that they look like weeds when they are young seedlings. Cleomes don’t usually bloom until they are well established in the garden, unlike pretty marigolds or bright New Guinea impatiens. Even though they can be planted in early spring, many gardeners choose to plant seeds directly in the ground in late fall in places with mild winters.
Cleome, also known as spider flower, is a gorgeous annual flower that adds vibrant color and unique texture to gardens. Getting the timing right for planting cleome seeds is important to ensure a successful growing season. In this comprehensive guide, we’ll cover everything you need to know about when and how to plant these flowering beauties.
Overview of Cleome
Before jumping into planting specifics, let’s do a quick overview of cleome.
- Botanical Name: Cleome hassleriana
- Plant Type: Annual
- Height: 3-5 feet
- Bloom Time: Summer
- Sun Exposure: Full sun
- Soil Type: Well-drained
Some of the most popular cleome seed varieties include ‘Helen Campbell’ ‘Rose Queen’, and ‘Sparkler Blush’.
Cleome is highly attractive to pollinators like hummingbirds bees and butterflies. The plants are also quite easy to grow, tolerate heat well, and are resistant to pests and diseases.
When to Direct Sow Cleome Outdoors
Cleome can be directly sown into the garden once the danger of frost has passed This timing varies by growing zone, but generally aim for early to mid spring after nighttime temperatures remain above freezing
The soil temperature should be at least 70°F for the best germination rates. Cleome seeds require light to sprout, so barely press them into the soil surface when planting.
Those in cooler climates can sow in late spring, while gardeners in zones 9-11 can often plant in early spring or even late winter.
Starting Cleome Indoors
For earlier blooms, start cleome seeds indoors 4-6 weeks before your last expected frost date. Use a seed starting mix and provide bottom heat of 80-85°F for faster germination.
Because the seeds need light to germinate, simply press them gently into the soil surface and do not cover. Once seedlings have 3 sets of true leaves, harden them off for about a week before transplanting into the garden after all danger of frost.
Space cleome transplants 18-24 inches apart in full sun locations. Water them regularly until established.
Direct Sowing Cleome Tips
If sowing cleome directly in the garden, here are some tips for success:
-
Choose a site with full sun (at least 6 hours daily) and well-drained soil. Amend soil with compost to improve drainage.
-
Wait until 2-4 weeks after last expected frost date.
-
Sprinkle seeds on soil surface and press in gently. Don’t bury them.
-
Space seeds 12-18 inches apart. Thin later to 18-24 inches between plants.
-
Water seedlings regularly with a light mist to prevent washing away seeds.
-
Thin out weakest seedlings once they reach 2-3 inches tall.
Caring for Cleome Plants
Once your cleome is up and growing, proper care will keep the plants healthy and maximize blooms.
-
Water 1-2 times per week, allowing soil to dry out slightly between waterings.
-
Apply a balanced liquid fertilizer every 2-4 weeks.
-
Stake tall varieties to prevent toppling.
-
Deadhead spent blooms to encourage more flowers.
-
Monitor for pests like spider mites and treat promptly. Good airflow helps prevent diseases.
Tips for Maximizing Cleome Success
Follow these tips and your cleome planting will get off to the right start:
-
Test soil pH and amend if needed to 6.0-7.0 range.
-
Work compost into garden beds to improve drainage before planting.
-
Direct sow seeds in early to mid spring once soil reaches 70°F.
-
For transplants, start seeds indoors 4-6 weeks before last frost.
-
Allow 18-24 inches between plants for good air circulation.
-
Water weekly until established. Drought tolerant once mature.
-
Fertilize every 2-4 weeks with a balanced liquid fertilizer.
-
Deadhead spent flowers for continuous blooming.
Enjoy Vibrant Cleome Flowers All Season
With the right timing for planting and proper growing conditions, cleome will reward you with months of vivid color and unique, spidery flowers. Time those cleome seeds right and you’ll have these beauties gracing your garden well into the summer and fall. Just be sure to plant where their towering height can stand out and attract butterflies, bees, and hummingbirds.
Soil
Cleome does best in average garden soil or rich, well-drained garden loam.
Temperature and Humidity
Cleome grows best when it’s between 75°F and 80°F during the day and between 60°F and 65°F at night. The plant does not tolerate frost.
How to Grow Cleome Spider Plant from Seed Growing Cut Flower Garden Annuals
FAQ
Is Cleome hard to grow from seed?
Does Cleome come back every year?
How late can I plant Cleome seeds?
Where is the best place to plant Cleome?
When should Cleome seeds be planted?
Planting cleome seeds at the right time is crucial for their growth cycle and to ensure they thrive in the garden setting. Timing is critical, and my personal success with cleomes has come from sowing seeds directly into the garden in early spring, after the danger of frost has passed.
Do cleomes grow from seed?
Planting cleomes from seed usually results in a vigorous display of the tall, fragrant cleome spider flower. Newer cultivars, some in dwarf varieties of the cleome plant, have no fragrance and do not produce next year’s flowers as the seeds are sterile.
How far apart should Cleome seeds be planted?
Cleome seeds require light to germinate, so be careful not to cover them when planting. Learn more about germination light requirements here. Seeds should be planted 1/8th inch deep and left uncovered. Space 3 inches between seeds, and space 18 inches between rows. Thin to 18 to 24 inches apart when plants are 3 inches tall.
How do you start Cleome seeds indoors?
Starting cleome seeds indoors allows for a head start on the growing season. Cleome seeds need light to germinate, so when sowing, do not bury them deep in the soil. Instead, press seeds gently into the surface of a well-draining seed starting mix, making sure to maintain adequate moisture without causing waterlogging. Here’s an important tip:
How long does a Cleome flower take to grow?
Cleomes, or Spider Plants, will bloom until the first frost. In a windy area, they may require staking; they are disease and insect free. Butterflies and hummingbirds love to feast on cleomes. Cleome seeds may be started indoors or outdoors. They grow best in full sun; seeds will germinate in 8 to 12 days if temperatures are 70 to 80F.
When should cleomes germinate?
Look to germinate seeds early spring, timing it about 6 to 8 weeks before the anticipated last frost date of your region. For flourishing Cleomes, it is critical to provide a balance of water, nutrients, and proper pruning practices. My experience highlights these as the cornerstones of vibrant blooms and healthy plants.