People sometimes ask me about growing broccoli in pots, and I always reply that most vegetable plants, except for salad greens, will grow best in the largest possible pots. One broccoli plant in a 5-gallon pot will probably be OK, but a broccoli plant grown in a 15-gallon pot will be able to grow much larger and produce more sprouts.
Of course, broccoli grown in a garden bed can be the most productive, but many gardeners plant the little seedlings too closely, with the result being that the crowded adult plants fight with each other for sunlight, thereby producing fewer sprouts. Itâ€™s also not uncommon for crowded plantings to produce erratic, mixed beds in which some plants are big and others are dwarfed.
To allow for maximum sunlight exposure, an adult broccoli plant should be 2 to 3 feet away from its neighbors. Commercial growers that grow for a single crop of big heads will space their plants about 1 1/2 feet apart, but if the plants are more widely spaced, harvesting the waves of secondary and tertiary smaller sprouts will be much easier.
There is also some unnecessary confusion as to the best time of year to plant broccoli. Broccoli is a cool-season crop, so it should be planted in the fall in areas where the winter weather is not snowy. The plants that have overwintered produce the most bountiful harvests the following spring.
Broccoli can also be planted in early spring, and if the weather doesnâ€™t turn hot too quickly, these spring plantings can mature some respectable sprout heads. Nurseries also sell some heat-resistant varieties that will produce sprouts in warmer weather.
In all cases, a quick start for the young plants is the key to eventual success. Spindly little seedlings will seldom develop into robust plants. Seedlings should be exposed to very-high light conditions and should frequently be power-fed a diet of liquid fertilizations. When planted in the field, the plants respond very well to strategies such as burying manure 6 inches or 1 foot underneath the seedlings.
When Native Americans taught the pilgrims to bury a fish under each corn plant, they werenâ€™t just saving the starving colonists; they were imparting some of the best gardening advice ever. Having a big lump of nutrition underneath any plant is a good way to maximize its growth potential.
Aphids can sometimes cluster on broccoli plants, but I find that happens mostly on poorly fed and stunted plants. A big, vigorous broccoli plant usually produces its own defenses that ward off aphid gatherings.
The biggest pest problem for broccoli is the cabbage worm; these are inevitable. Luckily, the Bacillus thuringensis sprays, which are completely organic, are very effective against cabbage worms. I spray my broccoli and other cabbage-family crops with Bt two or three times in the fall and another two times in the spring.
The strong, sulfurous flavor of cooked broccoli sometimes puts off children and some adults, but I like it. Iâ€™m crazy for the awesome, electric-green color of lightly steamed, fresh broccoli. Something about that color screams healthy.