How To Grow Broccoli
Plant Type: Biennial
Scientific Name: Brassica oleracea
Light: Full Sun
Soil Type: Well drained, light, dry
Soil Temperature: 50 – 80°
ph Range: 6.0 – 7.0
Watering: Moist, not soggy
Plant (Payson): March – May / August – September
Planting Method: Seed or transplant
Germination (days): 4 – 7
Maturity (days): 65 – 70
Common Pests: Cabbage Loopers
Common Diseases: Mildew & Rot
The edible parts of the broccoli are the heads, leaves and the stalk. This veggie can survive frost and almost freezing temperatures, which makes them a good choice for gardeners in cooler climates.
When to plant—Spring: Broccoli prefer cooler climates so you will want to begin sowing broccoli seeds two to three weeks before the last expected spring frost. Sow seeds directly in the garden as soon as the soil can be worked. Broccoli seeds can germinate in soil temperatures as low as 40 degrees F. (Generally plan on planting between March 15 to May 15.)
When to plant—Fall: Gardeners often choose to grow broccoli in the fall because spring conditions may be unpredictable. If temperatures heat up early, heat stressed broccoli can cause small florets or bolt producing only flower buds instead. If using seed sow seeds directly into the garden, do so 85 to 100 days before the average first fall frost. (Generally plan on planting between August 1 to September 15)
Seeds or transplants: The choice is yours. Both can be grown successfully. Seeds are of course are less expensive, however, starter plants give you an instant garden and a head start.
Broccoli prefer a sunny location that gets at least six hours of sunlight. Broccoli plants prefer soil with a pH of 6.0 to 7.0. Prepare the soil with well-rotted manures, compost and organic fertilizers. In the heat of summer even heat resistant broccoli will need protection from our intense sun and high temperatures, so they will do better planted next to taller veggies that can shade them.
For an even earlier start plant seeds inside in starter pots approximately six weeks before the last predicted frost. Transplant in to the garden when seedlings are 4 inches tall 18” to 24” apart in rows 2-3 feet apart (the further apart you plant them the larger the heads.)
Select heat tolerant broccoli seeds and or plants. If using seeds sow them directly in your garden at 3″ apart, ½” deep, two to three weeks before the last spring frost. As the seedlings mature you will need to thin the plants to 18” to 24.” For an extended harvest period, plant successively (1-2 weeks between plantings).
Once your plants are well established mulch with compost to conserve water, prevent weed growth and keep soil temperatures down. Broccoli roots are very shallow so gently hand-pull weeds so as not to disturb the root system.
Broccoli grows best in soil that is kept moist by watering regularly. Watering close to the roots is recommended—soaker hose and spot watering with drippers work best. As heads begin to form cut down on watering and do not get the maturing heads wet.
Broccoli plants are heavy feeders so plan on adding of liquid fertilizers such as compost tea, Glen’s Magic Elixir or liquid seaweed weekly. If your soil is sandy or decomposed granite you will need to add extra nitrogen as well (blood meal is a good source of nitrogen). WEEDING
Broccoli roots are shallow so be careful when weeding. Because Broccoli are cool season vegetable mulch them to help keep the soil cool which in turn also prevents weeds. DISEASE
Yellow leaves: If the bottom leaves turn yellow your plans may need a high nitrogen/low phosphorous fertilizer—blood meal is a good choice.
Clubroot: Wilting plants may be due to this fungus in the soil. Carefully check the roots to see if they are misshapen and gnarled, if they are than this is the problem.The solution is to remove the entire plant and carefully disposed of in the trash container/do not compost the plant.
Powdery Mildew: If your broccoli plants look like they are dusted with fine white flour, they have powdery mildew. Powdery mildew is caused by a fungus. The first parts of the plant to be affected are usually the lower leaves. Fungus spores may spread to the stalks and head of your plant if not controlled by removing affected parts. If not controlled quickly powdery mildew may also spread to other plants in your garden. Sunlight, adequate space, watering close to the roots, and good air circulation help to prevent the powdery mildew.
Aphids, Flea Beetles, Cabbage Loopers, Cabbage worms
Harvest: It takes 90 to 120 days for the broccoli to reach harvest size in your garden. Most broccoli varieties will produce a central head 8 to 10 inches across. The head should be compact and dark green with no sign of loose florets or yellow flowers. Heads are still edible at the florets stage but are stronger in texture and flavor. So watch carefully and enjoy your broccoli at its peak of flavor.
Harvest your broccoli in the cool of the morning, cut the primary head 4-6 inches below the head being careful to not cut the lower leaves. Cut at a slight angle to encourage water run-off and prevent water from rotting the stem. Cutting the primary head will encourage side-shoots—the plant will continue to produce numerous tender side shoots–each 1 to 4 inches across–for as long as six weeks afterward.
Storage: Place broccoli in warm water with a little white vinegar and any pests should float to the top. Do not use hot water as this will destroy nutrients. Rinse and store in the refrigerator for up to two weeks—any longer and you will lose nutrients and the broccoli stems will become tougher.
Excess broccoli can be frozen for later use in plastic freezer bags. Be sure to blanch broccoli in boiling water for three minutes, plunging the broccoli into ice cold water to stop the cooking process. This will kill any harmful bacteria. Frozen broccoli may be frozen for up to six months. Broccoli may also be canned or pickled.