Broccoli Raab prefers soil with a pH between 6.0 and 7.0. To increase the fertility of your soil, mix up to four inches of mature compost into your soil. If your soil is in particularly poor condition, also add a high-nitrogen organic fertilizer to enrich the soil. Organic fertilizers like alfalfa, cottonseed meal, and manure are good choices for planting broccoli.
While broccoli prefers full sun, it will tolerate some shade.
Broccoli Raab does best when started inside and transplanted at about 3-4” high. This usually takes about 4-5 weeks. For a summer harvest, sow seeds 4-6 weeks before the last spring frost, planning on transplanting your seedlings into your garden beds about 3 weeks before the last spring frost. Because broccoli raab matures so quickly, you can plant every 2 weeks for extended harvests. For a fall harvest, determine your first fall frost date and count backward 45 to 60 days (depending on variety) to figure out when you need to start your seeds. Floating row covers can extend your season by several weeks.
Depending on variety, space your plants 12” apart in rows 24-36” apart.
Apply an organic mulch made of mature compost, leaves, or bark to keep weeds in check and soil temperature regulated.
Allow your plants between one and one and a half inches of water per week. Broccoli likes moist (but well-drained) soil. In particularly hot or dry conditions, increase the amount of water you feed your plants.
Use an organic, nitrogen-rich fertilizer when your broccoli plants begin to form new leaves. Fish emulsion works well for fertilizing broccoli plants. You can continue to fertilize the plants about once a week until they are ready for harvest.
Broccoli plants have very shallow roots. If you disturb the soil you may accidentally break roots and damage your broccoli plants. If weeds develop around the plants, suffocate them with mulch instead of plucking them from the ground to avoid disturbing the roots.
You want to harvest your broccoli raab from the outside, and the inside may continue to make sprouts for a couple of weeks. Harvest when the buds are tightly closed and dark green. Avoid waiting until the buds begin to flower into light green or yellow flowers.
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