What to Sow in May: Your Breakout Guide for a Flourishing Garden

Introduction
May’s balmy days and reliably frost-free nights make it the ultimate month to sow a diverse palette of vegetables, herbs, flowers, and cover crops. By choosing the right crops now, you’ll enjoy continuous harvests, vibrant blooms, and improved soil health right through to autumn. This breakout guide helps you plan what to sow in May for maximum impact, with succession strategies, site preparation, and care tips.

1. Quick-Turnaround Salad Crops

• Rocket & Mizuna: Germinate in 5–7 days; sow in 1 cm drills, thin to 5 cm; succession sow every 10–14 days.
• Leaf Lettuce & Baby Leaf Mixes: Ready in 3–4 weeks; line containers or border edges.
• Mustard Greens & Pak Choi: Germinate in 7–10 days; partial shade helps prevent bolting.

2. Second-Wave Roots & Alliums

• Radishes (Cherry Belle): 4–6-day germination; harvest baby radishes in 3–4 weeks.
• Carrots (‘Nantes’): 10–21 days; sow 0.5–1 cm deep, thin to 5 cm for sweet baby roots in 6–8 weeks.
• Beetroot: 7–14 days; thin to 10 cm spacing for tender midsummer pulls.
• Spring Onions & Shallots: 7–14 days; sow in rows, succession sow fortnightly.

3. Heat-Loving Vegetables

• French & Runner Beans: Sow when soil > 12 °C; bush beans 5 cm deep, 5 cm apart; runners 10–15 cm with supports.
• Courgettes & Summer Squash: 5–8-day germination; plant 2 seeds per hill, 60 cm apart; expect harvest in 8 weeks.
• Sweetcorn: Sow in 4×4 blocks for pollination; 2 cm deep, 30 cm spacing; succession sow mid-May to extend harvest.

4. Herbs & Edible Flowers

• Basil & Coriander: 7–14 days; succession sow every 3 weeks for continual fresh herbs.
• Nasturtiums: 7–10 days; sow 2–3 cm deep in poor soil to deter pests and add peppery petals to salads.
• Borage & Calendula: Surface-sow; attract pollinators and yield edible flowers.

5. Flowers for Late-Summer Colour

• Cosmos & Zinnia: 7–10-day germination; sow 1 cm deep, thin to 30 cm for pollinator-friendly drifts.
• Marigolds & Calendula: 5–7 days; sow in gaps to deter nematodes and add bright edging.

6. Cover Crops & Green Manures

• Buckwheat & Phacelia: Broadcast on exhausted beds; cut and incorporate in autumn for organic matter and weed suppression.
• Crimson Clover: Sow in blocks for nitrogen fixation and autumn soil feed.

7. Succession Sowing Strategies

1. Staggered Drills: Divide beds into thirds; sow quick crops every 10 days.
2. Intercropping: Plant radishes between slower brassicas or tomato hills.
3. Container Rotation: Clear spent pots and reseed with salad or flower mixes.

8. Site Preparation & Sowing Tips

• Soil Prep: Remove weeds; fork to 15–20 cm depth; incorporate 3–5 cm well-rotted compost.
• pH & Drainage: Aim for pH 6.0–7.0; improve heavy soils with grit or sand.
• Sowing Depths:
  • Salad leaves: 0.5–1 cm
  • Roots: 1–2 cm
  • Beans: 3–5 cm
  • Courgettes: 2–3 cm

9. Aftercare: Watering, Feeding & Pest Control

• Watering: Keep the topsoil evenly moist for germination; transition to deep, infrequent watering once established.
• Feeding: Side-dress fruiting crops fortnightly with balanced feed; avoid over-feeding salad greens.
• Pests: Use slug traps around brassicas; net peas and beans; interplant with nasturtiums for natural deterrence.

Conclusion

May sowings kickstart a second wave of productivity in your garden. By selecting fast greens, second-wave roots, heat-loving veg, herbs, flowers, and cover crops, and applying succession strategies, you’ll enjoy continuous harvests and colourful borders from midsummer through autumn.

Top 10 Questions & Answers

1. What salad crops can I sow in May?
   Rocket, mizuna, leaf lettuce, and baby leaf mixes—harvest from 3 weeks.
2. Can I still sow beans in May?
   Yes—French and runner beans sown now yield pods from July onward.
3. How deep should I sow carrots?
   0.5–1 cm in fine tilth; thin to 5 cm for baby carrots in 6–8 weeks.
4. Which herbs are best sown in May?
   Basil, coriander, nasturtium, borage—succession sow every 3 weeks.
5. What flowers can I sow for autumn colour?
   Cosmos, zinnias, marigolds, calendula—they bloom until first frost.
6. How do I protect seedlings from slugs?
   Use organic slug pellets or collars around young plants at dusk.
7. What cover crops are suitable in May?
   Buckwheat, phacelia, crimson clover—for weed suppression and soil feeding.
8. How often should I succession-sow salad greens?
   Every 10–14 days for an uninterrupted supply.
9. Do courgettes need feeding?
   Yes—weekly feeds of high-potassium liquid fertilizer boost fruiting.
10. When should I water new May sowings?
    Lightly daily until germination, then deeply 2–3 times weekly.