Coleus Rainbow Mix Seeds
When should I plant
Coleus seeds do not require any treatment (soaking or stratification) before sowing.
Start seeds indoors 6–8 weeks before the last frost, or sow directly outdoors after the danger of frost has passed. Transplant them outdoors when temperatures are warm and stable, as coleus is sensitive to cold.
Site consideration
Choose a location with well-drained, fertile soil with pH between 6.0 and 7.0. Coleus grows well in garden beds, borders, and containers, especially in areas protected from strong winds.
Water
Well-draining soil is important for coleus to prevent root rot.
Container-grown coleus requires more frequent watering than those grown in the ground. Water daily, or sometimes twice a day, depending on heat and soil dryness. Ensure the pot has good drainage.
For coleus grown in the ground, water whenever the top 1–2 inches of soil is dry. Leaves will dry out and turn brown if the plant does not receive enough water.
Sunlight
Rainbow Coleus seeds require light to germinate and should be exposed to bright, indirect light. Once grown, they thrive in partial shade or in morning sun with afternoon shade to maintain vibrant foliage color.
Transplant
Transplant rainbow coleus when they have two sets of true leaves, moving them into 4-inch pots or directly into the garden after all frost danger has passed. Use well-draining, nutrient-rich soil and plant them at the same depth as their previous container. Providing partial shade and keeping the soil consistently moist.
Seed Germination
Seeds typically germinate in 10–14 days. Press them lightly onto the soil surface without covering, as they require light to germinate.
Seeding Rate
For Rainbow Coleus, the typical coverage rate is approximately 1 ounce of seed per 1,000 sq ft when broadcast sowing.
Other Elements
Fertilization
Fertilizer is not necessary when growing coleus in fertile garden soil. But a balanced fertilizer applied once a month can produce bigger plants.
Container-grown coleus will need more frequent fertilizing as frequent watering can deplete the soil of nutrients.
Always use a balanced fertilizer for coleus. A fertilizer higher in phosphorus may result in leggy growth.
Weed control
To control weeds near rainbow coleus without harming the plants, apply a 2-3 inch layer of organic mulch (like wood chips or bark) to block light and suppress seeds growth. Hand-pull weeds when they are young and the soil is damp. Avoid tilling too close to the coleus to prevent disturbing its shallow roots.
Seed Storage
The seeds will maintain a high germination percentage if stored under proper conditions. How long your seeds remain viable will depend on the temperature and moisture levels the seeds are exposed to. Seeds which are improperly stored will quickly deteriorate if unprotected against high humidity and dramatic temperature fluctuations day after day.
For best results, keep the seed in our moisture-proof ziplock sealing bags, which provide a better moisture prevention effect. Glass jar or plastic containers with snap-on lids works well too, add a packet of desiccant before sealing into the seed, such as silica gel to remove any moisture remains in the storage container. Seed stored under these conditions will remain viable for as long as years.
Factors Which commonly Cause Poor Results
1. Improper drainage soil
2. Sowing depth more than one inch
3. Covering the seed too deep beneath the soil surface
4. Cover a large area with a small amount of seed.
5. Plant at a wrong time of a year
6. Lack of sunlight
7. Inadequate rainfall after seed germination. The area should not be allowed to become completely dry. Supplemental watering may be required to sustain plant life.
8. Extreme weather conditions: hail, drought, excessive rainfall, floods, unseasonably cold temperatures.