Radishes have been cultivated since ancient Egypt and were one of the earliest European crops. Their name comes from Latin 'radix', meaning 'root'. Valued for their rapid growth and peppery flavour, radishes were brought to Australia by settlers and remain a quick-growing staple for cool-season planting.
Sowing Calendar
Best Months to Plant – Radish
Climate Zone
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Cool/Mountain
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Temperate
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Arid
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Subtropical
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Tropical
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Cool/Mountain – Radish
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
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Plant out transplants
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Direct sow
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Temperate – Radish
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
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Plant out transplants
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Direct sow
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Arid – Radish
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
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Plant out transplants
✓
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Direct sow
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Subtropical – Radish
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
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✓
✓
✓
✓
✓
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✓
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Plant out transplants
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Direct sow
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Tropical – Radish
Method
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Start in trays
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
Plant out transplants
✓
✓
✓
✓
✓
✓
✓
✓
✓
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Direct sow
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Where to Plant
In-Ground Garden Beds
In-Ground Garden Beds
• Traditional garden beds dug directly into the soil
• Suitable for deep-rooted crops and long-term plantings
• Offers natural soil ecology and drainage benefits
• Requires proper soil preparation and weed management
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
Pre-treatment
None Identified
There are no pre treatments required for germination.
Sowing Method
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
Drill Sow
• Make shallow, straight furrows (drills) in the soil using a stick or finger
• Sow seeds evenly along the length of the furrow
• Cover lightly with soil and water in gently
• Ideal for crops sown in rows like carrots, lettuce, and spinach
• Label rows and maintain even spacing for easy weeding and harvesting
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
Radish maintenance includes thinning early and harvesting promptly to prevent woody roots. Succession sow every couple of weeks for a continual crop. Keep soil moist to promote quick, tender growth.
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.
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.
Caterpillars & chewing larvae
Caterpillars and chewing larvae are moth and butterfly young that devour leaves or bore into stems and fruit, reducing growth and spoiling harvests.
Hand‑pick where practical and protect young crops with fine netting. Encourage parasitic wasps and birds. Apply Bacillus thuringiensis (Bt) for an organic, caterpillar‑specific control. Broad‑spectrum insecticides can work but may harm beneficials, so reserve for severe cases.
Slugs & snails
Slugs and snails chew irregular holes in foliage and fruit and can wipe out seedlings overnight, especially in damp, sheltered spots.
Remove hiding places, water in the morning, and use beer traps, boards, or shelters to concentrate and hand‑pick. Copper barriers can deter them. For baits, iron‑based pellets are the safest organic option; use metaldehyde baits cautiously due to risks to pets and wildlife.
Flea beetles
Flea beetles 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.
Clubroot
Clubroot 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
• Radish is prone to pithy or spicy roots if grown too slowly. Good cultural practices such as timely sowing, consistent care, and soil preparation can help manage this.
• Radish is prone to hollow centers in heat. Good cultural practices such as timely sowing, consistent care, and soil preparation can help manage this.
• Radish is prone to greening if left exposed. Good cultural practices such as timely sowing, consistent care, and soil preparation can help manage this.
