Broccoli that matures during cool weather is the sweetest you will ever taste. High temperatures can cause broccoli to become bitter and lose head formation leaving you with smaller and less tasty florets. So, if you want sweet tasting broccoli here in the Bluegrass Region don’t plant until August 1st.
However, if you want to plant broccoli for your summer garden, then broccoli grows best in full sun in rich organic soil. It likes a more acid soil pH (between 6.0 and 6.8), so think about mulching with pine needles. Plant broccoli 15 to 18 inches apart and if growing in rows, set them 12 to 24 inches apart.
There are several different types of broccoli, most of them being green, but there is a purple broccoli and one that is yellowish-green. Varieties are different in how compact they are and the number of sprouting lateral heads.
Broccoli is a heavy feeder so working in some rich compost or a thin layer of well-aged manure before planting will help the plants get off to a good start.
Harvest broccoli heads before they begin to show yellow (unless you have planted a yellow variety). At maturity, the head should be 6 to 10 inches across. The lateral heads will be smaller. When harvesting, cut about 6 inches of the stem and leaves.
Use broccoli as soon after picking as possible. If you are not going to use it the same day, then blanch the heads and freeze for later use.