Timing is key!! Broccoli likes to stay cool.
Causes of no or poor flower heading:
- Alternating periods of abnormal high temperatures followed by abnormal low temperatures stresses the plant and causes heading to come to a complete halt.
- Stress brought on by drought or inadequate moisture.
- Excessive nitrogen can cause huge healthy plants with little or no head production.
- Transplanting too late with root bound plants will keep the broccoli from heading.
- Transplants when exposed to temperature of 40 degrees and below for 1 – 2 weeks triggers heads to form too early or not at all.
- Transplants not properly hardened off will be stressed and perform poorly. https://papasgardens.com/2015/04/24/what-does-it-mean-to-harden-off-seedlings/
- Overcrowding results in either little or no head formation due to competition for adequate water and nutrient.
- Proper timing of transplanting for your specific area. Your County Cooperative Extension Service will supply the dates for planting.
- Proper planting of transplants 2 feet apart.
- Even supply of moisture. Drip irrigation is best.
- Balanced nutrition/fertilization. Avoid excessive applications of nitrogen.
- Proper hardening off of transplants.
- Cover planting when temperatures drop below 50 degrees. Low tunnels with floating row cover or cloches will provide protection.
- Plant in Fall.
- Decreased pest pressure.
- Plants are usually stronger. The flower heads are bigger.
- Plants grow better into cooler weather.
- Sow seeds for transplants 10 – 12 weeks before first frost.
- Set transplants 2 feet apart for extended season planting.
Broccoli are sensitive to their environment. When treated with care, they will reward you!