Broccoli is a must for every north Florida vegetable garden in the cool months of late fall and early spring. It is easy to grow and needs little protection from insects in most instances.
Broccoli is best when it matures in cold weather, so in north Florida we want to put seedlings out during the months of August-February. You can find seedlings at garden centers, Lowes, Home Depot and other places throughout north Florida from about September-October and again in late January or February.
I get my best results when I put seedlings out in mid-October and again in February. This way I avoid having broccoli in the garden during the coldest time of the year. Freezing temperatures can cause broccoli to ‘button,” or form heads too soon.
The broccoli head is generally ready for harvest about 60 days after planting. Many broccoli cultivars will produce numerous side shoots for weeks after the main central head is harvested.
Suggested varieties of broccoli for north Florida gardens are Early Green Sprouting, Waltham 29, Atlantic, Green Comet and Green Duke. In recent years the seedlings available locally have been Packman and Early Dividend. Both have performed well in my Niceville vegetable garden.
I like to space broccoli plants 24” apart in rows 30” apart, but they can be as little as 18” apart in rows that are 24” apart. If you are doing intensive farming, they can be planted 15” apart on centers.
Make sure you firm the soil well around the roots. Not doing so could lead to a smaller central head.
I generally mix in a good quality fertilizer in the soil before I put the seedlings out and then side dress the plants a couple of times over the next 60 days. Use a balanced fertilizer such as a 10-10-10, or maybe something with a little more phosphorus, such as an 11-15-11. A good quality fertilizer will have both fast and slow release forms of nitrogen and include a good micronutrient package. Also before planting I usually mix some organic material into the soil such as compost from the yard or composted cow manure from the garden center.
Broccoli does very well in containers. Just use a good quality potting mix.
Seedlings may be attacked by cut worms. You can protect them by covering the plants with a row cover or fashioning tinfoil collars around the seedlings at soil level. As the plants grow, watch for holes in the leaves of the plants. As soon as they appear, apply a Baccillus thuringiensis (BT) product such as Dipel dust, or Thuricide, a liquid concentrate (typically available at Ace Hardware). Apply again about a week later to kill the worms that will be hatching out at that time. BT products are natural biological products.
The plants need to be kept moist, so that means watering every second or third day in north Florida if we don’t have rain. Not enough water will stunt the growth of the plants or lead to buttoning.
Harvest the central head while the buds are firm and still tight. Simply make a diagonal cut about 4 to 6 inches below the head. In warm weather you need to inspect the heads daily because they can become over mature very quickly.