Can you plant carrots in late summer?
Written by
Tina Carter
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Late summer carrot planting provides super sweet happiness if the timing is right. Sow your seeds 10 weeks before your first expected frost (generally July-August everywhere). This gives the roots time to grow during the cool nights of fall and have their starches turned into natural sugar by a good frost! Fast-maturing carrots, such as 'Nantes' or 'Bolero', work well.
Timing Precision
- Calculate backward from first frost date
- Allow 70-80 days for maturity before hard freeze
- Zone 5: Sow by August 1; Zone 7: August 20
Variety Selection
- Choose <60 day types: 'Nantes', 'Yaya'
- Avoid slow winter varieties like 'Danvers'
- Prioritize bolt resistance in warm soils
Frost Management
- Protect seedlings below 25°F (-4°C)
- Use row covers anchored securely
- Remove covers when temperatures exceed 40°F (4°C)
Soil Preparation
- Mix 1 inch compost into top 8 inches (20 cm)
- Maintain pH 6.0-6.8 with lime if needed
- Pre water beds before sowing
Prepare the soil carefully for late crops, incorporating well-rotted compost to help retain moisture. Make ½ inch (1.3 cm) furrows, 12 inches (30 cm) apart. Soak the ground before sowing, then cover the seeds with vermiculite, not soil, as this prevents crusting and thus hinders germination in warm weather.
Water management prevents heat stress. Give 1 inch (2.5 cm) water weekly via drip irrigation. I mulch seedlings with straw after they reach about 3 inches (7.5 cm); falling below that height keeps soil temperatures cooler than 75°F (24°C). Watering at dawn minimizes evaporation; keeping the roots consistently moist also deters bitterness and cracking.
Frost changes the flavour, wonderfully. A temperature ranging from 32-40°F (0-4°C) will cause them to produce sugar to a wonderful extent. They will sweeten without spoiling the texture, and roots should be sold or used 3 or 4 days after they have received the lightest frosts, never allowing them to be frozen hard. My sweetest carrots were harvested in November.
Guarding against an early cold snap - Remind yourself to put up your 'hoop tunnels' before temperatures drop. ½ oz/sq yd row covers should do the job, secure edges with soil or sandbags. Ventilate on sunny days when it is above 50°F (10°C). Such measures can extend growth by 4 weeks. I have my covers lined up from September!
Read the full article: 5 Key Signs: When to Harvest Carrots Perfectly
