Planting Out Overwintering Onions and Garlic in August
August is the secret start to next year’s onion and garlic harvest! By planting overwintering varieties now, you give these alliums plenty of time to root and establish before the cold sets in—resulting in earlier, bigger bulbs in late spring and early summer. Here’s how to get your onions and garlic off to a flying start this August.
Why Plant Onions and Garlic in August?
- Root Establishment: Warm soils encourage vigorous rooting before winter slows growth.
- Beats the Rush: August planting means harvest up to a month earlier than spring-sown crops, often with larger bulbs.
- Weed Suppression: Strong, established alliums outcompete winter weeds.
- Low Maintenance: Once planted, onions and garlic need little extra care until late winter.
Best Varieties for Overwintering
Onions:
- ‘Radar’ (classic, reliable)
- ‘Electric’ (red-skinned, sweet)
- ‘Senshyu Yellow’
Garlic:
- ‘Solent Wight’
- ‘Carcassonne Wight’
- ‘Germidour’
- Look for any locally recommended autumn/overwintering types.
How to Plant Overwintering Onions
- Prep the Bed:
- Weed thoroughly and add compost or well-rotted manure.
- Rake soil level and firm gently.
- Plant Sets:
- Push onion sets into soil, root end down, 10–15cm apart, in rows 25–30cm apart.
- Tips should sit at or just below surface—don’t bury too deep.
- Water In:
- Give a thorough soak after planting.
How to Plant Garlic
- Split Bulbs:
- Break into individual cloves, keeping papery skins intact.
- Plant Each Clove:
- 5cm deep, 15cm apart, tip up, rows 25cm apart.
- Firm Gently and Water:
- Label the row and keep well-watered if August is dry.
Ongoing Care
- Weed regularly: Young onions and garlic don’t compete well.
- Mulch: A light covering of compost or straw in late autumn helps insulate during frost.
- Protect from Birds: If birds pull out sets, cover with mesh or netting until roots anchor.
- Feed: Top-dress with a general fertilizer in early spring for a growth boost.
Problems & Solutions
- Bolting: Choose bolt-resistant varieties; avoid planting in very loose soil.
- Rot/Waterlogging: Beware of overwatering—ensure well-drained beds.
Harvest Timeline
- Green shoots: Begin picking mild, green onions in late spring.
- Bulbs: Onions ready June–July; garlic from late May onwards, depending on variety and season.
Starting onions and garlic in August is one of the simplest steps to a bigger, earlier harvest next year. A little prep now pays big flavour rewards—and homegrown alliums store for months, making them kitchen staples you’ll always have on hand.
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Plant overwintering onions and garlic in August for an early, abundant harvest next year. Step-by-step planting, variety selection, care, and harvest timing for these autumn alliums.### Planting Out Overwintering Onions and Garlic in August
August is the perfect time to give onions and garlic a head start for next year’s harvests. Setting them out now means strong roots before winter and full, flavourful bulbs in early summer. Here’s how to ensure a bumper allium crop by taking action this month!
Why Plant in August?
- Strong Root Growth: Warm soil speeds up establishment, helping plants withstand cold and wet conditions later.
- Earlier Harvests: August-planted alliums mature weeks ahead of spring-planted ones.
- Less Weed Competition: Established plants outgrow weed seedlings in early spring.
- Low Maintenance: Once in, they look after themselves until next spring.
Best Varieties for Overwintering
Onions:
- ‘Radar’, ‘Electric’ (red), ‘Senshyu Yellow’, or any variety labeled for overwintering.
Garlic:
⭐ Recommended Products — Garden & Allotment Essentials for March
March is when the growing season truly begins. Seeds are being sown daily, beds are prepared and late frosts are still possible — these essentials help produce strong plants and a successful start.
Seed Trays, Modules & Propagation Kits — perfect for tomatoes, brassicas, lettuce, onions and flowers. 👉
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Heated Propagators, Heat Mats & Grow Lights — improves germination and prevents leggy seedlings during cold nights. 👉
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Seed & Cutting Compost — essential for healthy seedlings and strong root growth. 👉
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Garden Fleece & Plant Protection Covers — protects seedlings, potatoes and early plantings from late frost. 👉
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Spring Vegetable Seeds — carrots, beetroot, peas, spinach and salads can all be started now. 👉
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Garden Kneeler & Seat — makes long sowing and planting sessions far more comfortable. 👉
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Pressure Washer (Greenhouse & Patio Cleaning) — clean patios, paths and greenhouses before planting. 👉
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Solar Garden Lights — perfect for enjoying the garden during brighter spring evenings. 👉
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- ‘Solent Wight’, ‘Germidour’, ‘Carcassonne Wight’, ‘Messidrome’—choose varieties suited to autumn planting and your climate.
How to Plant Overwintering Onions
- Prepare the Bed: Remove crops and weeds, fork in compost, and break up clumps.
- Plant Sets: Firm the soil; push onion sets in about 2cm deep, 10–15cm apart in rows 25–30cm apart. Tips should just show.
- Water: Give a thorough drink, especially if dry.
How to Plant Garlic
- Split Bulbs into Cloves: Keep skins on.
- Plant Each Clove: 5cm deep, 15cm apart, with the tip pointing up. Space rows 25cm apart.
- Firm and Water: Label the row and water well.
Ongoing Care
- Keep Weed-Free: Alliums hate competition in their first months.
- Mulch in Autumn: A thin layer of straw or leaf mold helps insulate in a harsh winter.
- Protect from Birds: Cover with netting until shoots are established if birds are a problem.
- Feed: Once growth resumes in spring, top dress with organic fertilizer or liquid feed.
Problems & Solutions
- Rot: Always plant in well-drained spots; avoid low-lying, soggy soil.
- Bolting: Plant only firm, healthy sets or cloves and avoid disturbing after root establishment.
Harvesting
- Green Shoots: Use as mild spring onions in late winter/early spring.
- Bulbs: Harvest garlic from late May to July; onions from June to July, when leaves yellow and flop.
Planting out onions and garlic in August is quick and low-fuss—and locks in fresh homegrown alliums for late spring when the kitchen needs them most.