Is Coleus Poisonous? A Guide to Caring for This Warmth-Loving Plant

Coleus is a fairly common flowering plant in everyday life, with vivid colors, a great many varieties and easy propagation. It is a widely used foliage plant. Besides being displayed as a small foliage plant, it can also be arranged in patterned flower beds, and can be used as foliage in flower baskets and bouquets. So is coleus poisonous? How do you care for it?

I. Introduction to Coleus

1. Family and genus: Coleus is an upright or ascending herb in the genus Coleus (Plectranthus) of the mint family, Lamiaceae.

2. Appearance: The stems are usually purple, and the leaves are membranous and highly variable, usually ovate, with tips blunt to shortly acuminate and bases broadly cuneate to rounded; the margins have crenate-serrate teeth or crenations; the colors are varied, including yellow, dark red, purple and green. The verticillasters are many-flowered, with the flowers mostly densely arranged; the pedicels and inflorescence axis are finely pubescent; the bracts are broadly ovate; the calyx is bell-shaped with a two-lipped calyx limb, the middle lobe broadly ovate and the lateral lobes short and small, ovate; the corolla is light purple to purple or blue, with the corolla tube abruptly bent downward and the corolla limb two-lipped; the filaments are united into a sheath below the middle.

3. Flower form and flowering period: The style extends beyond the stamens, the disc is swollen at the front, and it flowers in July.

II. Is the warmth-loving plant coleus poisonous?

Coleus is not poisonous. Not all beautiful flowering plants are toxic. Coleus belongs to the mint family, Lamiaceae, and plants in this family generally do not contain toxins. What is more, some species such as perilla and mint can even be eaten!

A friendly reminder: Generally speaking, even poisonous plants only cause poisoning when they are eaten and so on, and when growing coleus we would not eat it, so we can plant coleus with peace of mind.

III. How do you care for coleus?

1. Soil requirements

Potted coleus requires a sandy growing medium rich in humus, loose and fertile, with good drainage and aeration.

2. Light conditions

When the light is soft and sufficient, the leaf color of coleus is strikingly vivid, but it dislikes direct strong sunlight under a clear midsummer sky, which makes the leaf surface rough and lose its gloss. In shaded conditions, the leaf color is also not vivid.

3. Watering tips

Coleus's water needs lie in keeping the potting soil and the environment moderately moist at all times. It dislikes drought and must be protected from waterlogging, so as to avoid the leaves dehydrating and losing color and the roots becoming infected with soft rot.

4. Temperature conditions

Coleus likes a warm, humid climate and fresh, clean air. Indoors in winter the suitable temperature is 20°C to 25°C, and the minimum overwintering temperature must not be below 10°C. If the temperature is too low, the leaves turn yellow and drop, and below 5°C the plant dies.

5. Fertilizing tips

Coleus has low fertilizer requirements; during the growing season apply a dilute fertilizer based mainly on nitrogen 1-2 times a month.

6. Proper pruning

During the seedling stage, coleus should be pinched back several times to encourage side branches and make the plant full and bushy. After flowering, keep 2-3 nodes on some of the lower branches and cut away the rest, so that new shoots grow again.

7. Pest and disease control

Coleus is most easily attacked by aphids. Aphids hide on the leaves and suck the tender sap, causing the leaves to curl and even wither, so when aphid infestation occurs on coleus it must be controlled promptly. To reduce pollution, botanical pesticides can be used for control. The method is to take a certain amount of Chinese arborvitae (Platycladus orientalis) leaves, crush them, add 4-5 times the amount of water to dilute, and spray the affected plants; generally after 3-5 sprayings the pests can be eliminated.