Broccoli Stat Summary
Plant Spacing: 12-24" (304-609 mm)
Row Spacing: 18-36" (457-914 mm)
Planting Depth: 1/4" (6 mm)
Plants Per Person: 3
Soil Temperature: 55-75°F (13-24°C)
Days to Emergence: 5-17
Recommended Soil PH: 6.0-6.8
Seed Indoors: 6 weeks before transplanting
Earliest Outdoor Planting: Before Last Frost
Can direct seed outdoors
Can seed indoors
Broccoli grows best in cool, moist and moderate climates (temperatures under 85 degrees F). Due to an intolerance to heat, start broccoli indoors or in the greenhouse the beginning of February for transplanting in mid-March. This gives the broccoli a good foothold before warmer weather hits. Sow the seed 1/4 inch deep in an individual pot of sterile seedling mix with a soil temperate between 55 to 75 degrees F.
Keep the seedlings moist and nourished. Prior to transplanting in the garden, harden off seedlings in a cold frame. When the seedlings are 4 to 6 weeks old, transplant them a little deeper than indoors at about 12 to 24 inches apart in rows 18 to 36 inches apart. A liquid starter fertilizer applied to the seedlings at time of transplanting will help get them off to a good start.
Mulch around plants to protect shallow roots, reduce weed competition, and maintain cool and moisture soil. Even though broccoli tolerates an acidic environment, it grows best in garden soil with a pH of 6.0 to 6.8. For fall broccoli crops, you can plant seeds directly into the garden in mid-summer.
When the plants are half grown, side-dress with nitrogen fertilizer.
The spacing between plants will help determine the size broccoli heads yielded; closer give smaller central heads.
Harvesting and Storing Broccoli
Harvest the center green bud cluster of broccoli while the buds are still tight and before any yellow petals begin to show; this is about 2 months after transplanting. Use a sharp knife, cut the central stem at a 45 degree angle about five to six inches below the head; include a few wrapper leaves with the head. Removing the central head will stimulate production at the remaining axillary buds. Broccoli can be stored at a 40 degrees F temperature with 95% humidity.
Broccoli Insect and Disease Information
Cabbage worms are small green larva of the cabbage white butterfly. You can use row covers to keep them from eating small plants; hand pick and destroy on older plants. Aphids can be periodically sprayed off with a stream of water. Keeping the soil pH at or above 7.2 will help suppress club root; if needed, adding lime will raise your soil pH.
Broccoli Yield Information
Once you harvest the main crown of broccoli the plant will normally produce side shoots that can also be harvested.
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