Coleus brings vibrant colour to the shade garden with its boldly patterned foliage. Native to Southeast Asia, it gained popularity in Victorian England, where it was used in elaborate bedding displays. Today, gardeners across Australia grow coleus for its easy-care habit and stunning palette—proof that sometimes the leaves really are the star of the show.
Sowing Calendar
Best Months to Plant – Coleus
Climate Zone
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Cool/Mountain
✓
✓
✓
✓
✓
Temperate
✓
✓
✓
✓
✓
Arid
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Subtropical
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Tropical
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Cool/Mountain – Coleus
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
✓
✓
✓
Plant out transplants
✓
✓
✓
✓
✓
Direct sow
✓
✓
✓
✓
✓
Temperate – Coleus
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
✓
✓
✓
Plant out transplants
✓
✓
✓
✓
✓
Direct sow
✓
✓
✓
✓
✓
Arid – Coleus
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Plant out transplants
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Direct sow
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Subtropical – Coleus
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Plant out transplants
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Direct sow
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Tropical – Coleus
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Plant out transplants
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Direct sow
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Where to Plant
Shady Spots & Herb Gardens
Shady Spots & Herb Gardens
• Areas receiving dappled or indirect sunlight, often near trees or buildings
• Best for shade-tolerant herbs like mint, parsley, or greens like spinach
• Helps prevent sun stress and conserves moisture
• Often used in cooler corners of the garden
Containers & Pots
Containers & Pots
• Portable planting vessels suited for patios, balconies, and small areas
• Provide complete control over soil composition and drainage
• Great for herbs, greens, compact vegetables, or ornamental plants
• Allow plants to be moved to follow sun, shade, or seasonal conditions
Pre-treatment
None Identified
There are no pre treatments required for germination.
Sowing Method
Start in Trays
• Fill seed trays or punnets with quality seed-raising mix
• Sow seeds at the correct depth—refer to seed packet for guidance
• Place trays in a warm, sheltered location with good light
• Mist or bottom-water to avoid disturbing small seeds
• Transplant seedlings once they develop 2–4 true leaves
Direct Sow
• Sow seeds directly into prepared garden soil or outdoor containers
• Best for plants that dislike transplanting, such as root vegetables and beans
• Loosen soil and remove weeds before sowing
• Sow at the recommended depth and spacing, then water gently
• Keep the area moist until germination and thin seedlings if needed
Watering
Medium
• Benefits from regular watering, especially during active growth or flowering
• Soil should remain moist but not soggy—allow topsoil to dry slightly between waterings
• Ideal for most vegetables, herbs, and flowering annuals
• More frequent watering may be needed during hot or windy weather
• A layer of mulch can reduce water loss and improve consistency
Fertilisation
Frost
Frost Tolerant
These plants can tolerate light to moderate frosts and may survive through cooler seasons.
Maintenance and Harvesting
Coleus thrives with regular pinching to prevent flowering and encourage bushy growth. Water consistently and remove flower spikes as they appear. Trim back leggy stems to maintain shape and density.
Pests and Diseases
Aphids
Aphids are tiny, soft-bodied insects that cluster on new growth and the undersides of leaves. They suck sap from plants, causing leaves to curl, yellow or become distorted. As they feed, they excrete sticky honeydew that encourages sooty mould, and colonies can build quickly in warm weather.
Start with organic controls: blast colonies off with a firm jet of water, encourage beneficial insects like ladybirds and lacewings, and spray neem oil or insecticidal soap to disrupt feeding. Keep plants well watered and avoid excess nitrogen that promotes soft growth. If pressure remains high, selective chemical sprays can be used sparingly, taking care to protect pollinators and beneficials.
Crown / root rot (Wet)
Crown and root rots are caused by water‑loving fungi that attack stems at the soil line and roots below. Plants yellow, wilt, and eventually collapse because their roots can no longer supply water and nutrients—most common in heavy, waterlogged soils.
Prevention is key: improve drainage, raise beds, and water deeply but less often. Avoid injuring stems at the soil line and rotate away from affected beds. Solarising soil in summer can knock back pathogens. Chemical drenches have limited benefit in home gardens and are best used preventatively rather than curatively.
Downy mildew
Downy mildew causes pale yellow blotches on upper leaf surfaces with grey‑purple fuzz beneath, spreading fast in cool, moist weather. Heavily infected leaves collapse, slowing growth and yield.
Choose sunny, well‑ventilated positions, water early so foliage dries quickly, and remove infected leaves promptly. Organic options include copper and bio‑fungicides (phosphorous acid salts). For severe pressure, rotate chemical fungicide modes to prevent resistance.
Whiteflies
Whiteflies can affect plant health and yields in home gardens. Typical symptoms include slowed growth, discolouration, and reduced productivity, often triggered by weather, nutrition, or cultural conditions.
Start with cultural fixes: rotate crops, improve soil with compost, water consistently, and choose resistant varieties. Organic sprays or amendments can reduce severity; chemical options are a last resort and should be used carefully and in accordance with labels.
Mealybugs
Mealybugs can affect plant health and yields in home gardens. Typical symptoms include slowed growth, discolouration, and reduced productivity, often triggered by weather, nutrition, or cultural conditions.
Start with cultural fixes: rotate crops, improve soil with compost, water consistently, and choose resistant varieties. Organic sprays or amendments can reduce severity; chemical options are a last resort and should be used carefully and in accordance with labels.
Growing Tips
• Coleus scorches in harsh sun; give morning sun and afternoon shade for best leaf colour.
• Coleus stretches indoors with low light; move to a brighter spot or pinch to shape.
• Coleus loses colour in nutrient-poor mixes; feed lightly and water evenly.
