Autumn sowing in August: preparation and planning

August: preparing for autumn harvest

August is perhaps still full of summer crops, but for many gardeners it is the time to prepare for autumn and winter harvest. This season is the second growing season of the year. While summer vegetables (tomatoes, eggplants, peppers) still flourish, you are already planting for October-November-December harvests. This article helps you with it.

Why August? Simple: many autumn vegetables need 8-12 weeks from seed to harvest. If you sow in August, you harvest October-December, when market prices are high and your homegrown vegetable is truly valuable.

Which vegetables to sow in August?

Sow directly in ground (August):

• Radish (Radish Icicle, Radish Scarlet, Radish Black Spanish) - 3-4 weeks to harvest
• Corn (sweet corn, late varieties) - 10-12 weeks
• Beans (pole beans, broad beans late) - 8-10 weeks
• Spinach (winter spinach, "Bloomsdale Long Standing") - 6-8 weeks
• Arugula (wild arugula, arugula selvatica) - 4-5 weeks
• Lettuce (autumn lettuce, "Salad Bowl") - 6-8 weeks
• Leek (winter leek, "Carina", "Toledo") - 12-14 weeks
• Purslane (summer purslane) - 5-6 weeks
• Radish/Mustard - 3-4 weeks

Seedlings (sow in pots, prick later):

• Broccoli (winter broccoli, "Arcadia") - sow now, prick September, harvest December
• Cauliflower (autumn kale, "Arcadia") - sow now, prick September, harvest December
• Cabbage (red cabbage, chicory) - sow now, prick September, harvest December
• Parsley (flat parsley) - sow now, slow growth
• Chives (chives) - sow now, harvest next spring

Root vegetables:

• Carrot (winter carrot, "Flakkee", "Nantaise") - sow now, harvest December
• Beet (red beet, "Detroit") - sow now, harvest October-November
• Rutabaga - sow now, harvest October

The planting calendar for August sowing

Sow - Harvest timeline:

How to sow in August?

Soil preparation: August is dry. Ensure your seed bed is well moist before sowing. Dig 5 cm deep, add compost (handy: 2 cm), mix well. Soil must be light and moisture-retentive. Not waterlogged, but not dry either.

Sowing depth: This is crucial. Shallow sowing is far more often the problem than deep. Rule: sowing depth = 2-3 times seed diameter.

• Small seed (spinach, arugula): 0.5-1 cm deep
• Medium (lettuce, beet): 1-1.5 cm deep
• Large (beans, corn): 3-4 cm deep

Space between seeds:

• Radish: 5 cm
• Spinach: 10 cm
• Lettuce: 20-25 cm (thin later to 30 cm)
• Leek: 5-10 cm (thin later)
• Beans: 20 cm
• Corn: 20 cm (rows 50 cm apart)

Water after sowing: This is the key. After sowing YOU MUST water. Not spray (that washes seed away), but gently spray until the top 2 cm of soil is well moist. Then keep moisture constant until sprout appears (usually 5-10 days).

Seedlings: broccoli, cauliflower, cabbage

These are the "long term" vegetables. You sow them now in pots (one seed per pot, in seed soil or seed compost). They grow slowly in the first weeks. Early September you prick them (repot to larger pot), and they grow through until December-January when you set them in the ground.

Seedling process:

1. Seed tray with seed soil (50% peat moss, 50% sand or perlite)
2. Set seed 1 cm deep
3. Spray until moist
4. Place tray in warm spot (20-22°C), not direct sun
5. After sprout: place in light, not as warm
6. Water when top layer feels dry

Timing: Sow broccoli/cauliflower/cabbage early August. They are ready to prick early October. Late September in large pots (one plant), and October in ground. Harvest December-January.

How to water after sowing?

This is where many fail. August is dry and warm. Newly sown beds MUST be kept well moist. This can mean spraying twice daily.

Golden rule: Seed bed must NEVER dry out between waterings. Soil moisture meter (cheap) helps. Otherwise: test by sticking your finger 2 cm in soil. Feels dry? Water. Feels moist? Not needed.

Do not wait until morning. In August seed can dry between waterings, germination fails, and seed dies.

Harvest in October-December

This is where it gets fun. Radish, arugula, spinach can be picked from October. Lettuce can be fully harvested October-November. Broccoli, cauliflower harvest December-January. Carrots, beets: October-November, and they keep well in ground until January.

This is also your advantage: gardening August-December gives you harvest in the expensive season (October-December) when fresh vegetables are dear.

Step-by-step

Step 1: Choose your vegetables

Determine which autumn vegetables you want. Write them down. Check maturity (on packet).

Step 2: Seed bed prep

August, add compost, mix well, water until moist.

Step 3: Sow

Plant seed at right depth and spacing. Water gently after sowing.

Step 4: Water quality

Check twice daily in August. Seed bed must not dry out.

Step 5: Seedlings in pots

Set seedlings (broccoli, cauliflower, cabbage) in pots. Place in light, not hot.

Frequently asked questions

Why sow so late?

Later sowing means harvest in October-December, when fresh vegetable is much more valuable. Plus: insect pests diminish in autumn.

Can I sow vegetables from seed in August?

Yes, many things. Spinach, arugula, radish, lettuce are perfect August-seed vegetables with short maturity (3-8 weeks).

My seed doesn't come up? Why?

Usually: sown too deep, or seed bed dried. Check sowing depth on packet. Test seed with moisture.

Carrots don't germinate. What do I do?

Carrots germinate slowly and need constant moisture. If they don't appear after two weeks, resow. Ensure seed bed is really moist until sprout.

My seedlings grow slowly. OK?

Yes. Broccoli, cauliflower actually grow slowly, especially in the first month. This is normal. They speed up late September as temperature drops.

Frequently asked questions

Do I sow in open ground or in trays?

Both work. Open ground better for long-term vegetables (leek, carrot). Trays better for quick vegetables (radish, arugula) because you control volume.

Can I buy plants from seed instead of sowing myself?

Yes, quicker. August, buy young plantlets of broccoli, cauliflower, cabbage at shop. Plant directly in ground. Harvest October-November (faster than own sow).

Which nutrients do I add for autumn sowing?

Compost (2 cm) usually suffices. For extra growth: aged manure (older than 1 year) add. Artificial nutrients: nitrogen helps leaves, phosphate and potassium help roots.

Frequently asked questions

Can seed be stored after August?

Yes. Seed keeps well until next summer in cool, dry place (15°C, 40% humidity). Not in heated room.

Can seedlings overwinter outside?

Some: yes. Broccoli, cauliflower, cabbage can overwinter outside in mild areas (Zone 7-8). In cold climate: protect with tunnel.

Sow lawn in August too?

Yes, grass seed can be sown August (early autumn grass seeding). This gives strong roots for winter. August to September is prime grass-seeding season.

Discover your own garden design

At [gardenworld.app](https://gardenworld.app) you can upload your front yard and plan where your autumn vegetables fit best - with attention to light, drainage, and growing space per type. Visualise your autumn garden before you sow.