Growing and Saving the Seed of Coleus
Latin name Coleus blumeii is a frost-tender annual member of the mint family that can be perennial in truly tropical climates. The colorful leaves and bushy stature make this a perfect house plant. It is also excellent for containers and landscaping. Plants are tropical and cannot handle cool weather. Tolerates shade and sun, making it very easy to grow.
Exact origins are unknown but believed to be Southeast Asia and introduced to the West in the 1800s. A wildly popular landscaping plant during the Victorian era.
- Ornamental and edible
- Beds, borders, containers, house plants
- Seeds germinate in 7-14 days.
- Surface sow seeds and lightly cover with a thin layer of fine potting soil.
- A humidity dome will help to keep seeds moist and warm until they germinate (dome is not necessary, just helpful).
- Direct sow after all danger of frost has passed and soil is quite warm, or start indoors 8-10 weeks before last frost and transplant out.
- Ideal germination temperature is 70-78 F.
- Plants prefer shade or part sun and rich, well-drained soil with plenty of moisture.
- Space plants 12-18 inches apart.
- Keep the small, inconspicuous flower spikes pinched back (like basil) to encourage healthy bushy foliar growth.
- Plants easily propagate from cuttings.
- Before first frost, take cuttings and root for indoor winter house plants. These super cold-sensitive plants will be killed even by light frost.
A number of soft-bodied insects may attack your coleus, from mealybugs to aphids and spider mites. Be sure to treat these infected plants regularly and thoroughly with organic approved horticulture soaps.
Seed saving is possible with coleus, but be aware that there will always be a bit of genetic variation in plants grown from seed.
- Allow flower spikes to mature on plant before harvesting seeds.
- Store in a cool, dark, dry place.
- It is also possible (and very easy) to propagate coleus from cutting; simply snip and root a few cuttings in late summer and keep indoors overwinter as a house plant. Propagate cuttings from this mother plant in spring and transplant rooted cuttings outdoors after frost.