Growing a mature head of cauliflower is highly variable. As a cool-season crop, its development is sensitive to environmental conditions, which affects the overall timeline. The process from planting to harvest generally takes between 50 and 100 days, depending on the variety and starting method. This timeframe covers the period needed for the plant to develop the edible flower structure known as the curd.
Calculating the Growth Timeline
Starting with Transplants
The most significant factor determining growth speed is whether the plant starts from seed or a young transplant. Using a transplant is the preferred method for a quicker harvest. Time to maturity is measured from the day the seedling is set into the garden soil. Many common varieties require 75 to 85 days after transplanting, while early-maturing cultivars can be ready in 50 to 60 days.
Starting from Seed
Starting from seed extends the timeline considerably due to the indoor germination and seedling growth phase. Seeds are typically sown indoors four to six weeks before the outdoor transplant date. The total time from seed to harvest can span three to four months, which is why transplants are recommended.
Critical Environmental Influences on Maturity
Temperature Requirements
Cauliflower is sensitive to inconsistent growing conditions, which can accelerate or delay maturity. The plant thrives within a narrow temperature band, ideally requiring average temperatures between 60 and 75 degrees Fahrenheit. Deviation outside this range is the primary cause of growth failure. Exposure above 75 degrees Fahrenheit can cause the plant to stop developing a large head.
Preventing Buttoning
A sustained period of cold weather, such as 10 days below 50 degrees Fahrenheit, can trigger “buttoning.” Buttoning is the premature formation of a small, unusable head that will not grow further. Inconsistent watering or dry soil conditions also stress the plant, contributing to buttoning and stunted growth.
Nutrient Needs
The plant requires a constant supply of moisture and specific nutrients to maintain its growth rate. Cauliflower demands high levels of nitrogen for vegetative growth. Boron, a micronutrient, is necessary for proper curd formation. A boron deficiency will result in brown or discolored heads, slowing development and reducing quality.
The Final Stage: Curd Formation and Protection
The final stage of growth begins when the plant is mature and the edible curd, an immature flower cluster, starts to appear in the center. The curd must be protected from direct sunlight to ensure it develops a snow-white color and mild flavor. Without protection, sun exposure causes the head to yellow or brown and develop a bitter taste.
This protection process is called blanching, which involves physically shielding the head from light. When the curd reaches two to three inches in diameter, the outer leaves are gathered and tied loosely over the top of the head. This creates a natural canopy that blocks the sun while allowing for air circulation.
Blanching is not required for self-blanching or colored varieties, but it is necessary for most traditional white types. After the leaves are tied, the curd expands rapidly underneath its cover. The head is typically ready for harvest seven to twelve days after blanching begins. Cauliflower is mature when the head is compact, firm, and has reached a diameter of six to eight inches.