Coleus is famous for its vibrant, patterned foliage, adding rich color to gardens throughout the summer. As a tropical perennial (Coleus scutellarioides), it cannot survive freezing temperatures. The direct answer to whether Coleus plants die in winter is yes; they will perish in most climates and must be protected or replaced annually. Intervention is necessary if you wish to enjoy your specific varieties again next year.
Why Coleus Dies: Understanding Its Natural Habitat
Coleus plants originate from tropical and subtropical regions, primarily in Southeast Asia and parts of Africa, where they grow as tender perennials year-round. This explains why the plant is heat-loving and sensitive to cold temperatures. In most of North America (USDA Hardiness Zones 2 through 9), Coleus is treated as a seasonal annual. The plant declines rapidly once temperatures drop consistently below 50°F (10°C), and sustained temperatures below 60°F (15.5°C) cause significant damage. Exposure to freezing temperatures causes water inside the cells to expand, rupturing the cell walls and leading to the plant’s collapse and death. To preserve your variety, bring it indoors before the first anticipated fall frost.
Option A: Saving the Existing Plant Through Overwintering
One method for preserving your plant is to dig it up and bring it indoors to grow as a houseplant. Before moving it inside, prune the plant back significantly, reducing the size by up to half. This minimizes transplant shock, encourages bushier growth, and helps the plant adjust to lower winter light levels.
Inspect the plant thoroughly for pests, such as aphids or spider mites, which can infest your indoor environment. A thorough spray with insecticidal soap or a strong jet of water helps eliminate any pests before the plant is settled inside. Place the potted Coleus in a location that receives bright, indirect light, such as a south- or southeast-facing window, or under a grow light.
Indoor winter care requires reducing both watering and fertilization. Since the plant’s growth slows during the short days of winter, it uses less water. Water only when the top one to two inches of soil feel completely dry to prevent root rot. Avoid applying fertilizer until the following spring when active growth resumes.
Option B: Starting New Plants from Cuttings
An alternative approach, especially for large garden plants, is to propagate new, smaller plants from cuttings to overwinter indoors. This method saves space and provides plants for the next growing season. Start by selecting healthy, non-flowering stems from the mother plant and cutting a section three to four inches long, ensuring the cut is just below a leaf node.
Remove the leaves from the bottom inch or two of the stem to prevent rotting. Coleus cuttings are easy to root and can be placed directly into a glass of clean water or a small pot filled with a sterile, soilless potting mix. Rooting hormone is generally unnecessary but can be used to speed up the process.
If rooting in water, change the water every few days; new roots typically appear within two to three weeks. If rooting in soil, cover the pot with a clear plastic bag or container to create a high-humidity environment, encouraging faster root development. Once the new plants have established a solid root system, keep them near a bright window and pinch back the growing tips throughout the winter to encourage a compact, full shape.