Broccoli is a cool-season staple in many home vegetable gardens, thanks to its easy care and high nutritional value. In this article, discover essential tips for how to grow broccoli from seed and keep it flourishing throughout the growing season.
Compared to other crops in the Brassica family, broccoli plants have a relatively long growing season. Depending on the variety, they take between 80-100 days to reach maturity.
Some growers in colder climates get a head start on the spring planting season by sowing broccoli seeds indoors in late winter or early spring. When transplanting nursery-grown broccoli seedlings, expect to harvest your broccoli heads in 55-85 days.
Best Tips and Tricks for Growing Broccoli from Seed
Broccoli plants require cool weather to form their dense central head. Ideally, the plant should reach maturity before the weather gets consistently warmer than 75℉.
Broccoli is also an excellent fall crop when planted in late summer. Read on to learn everything you need to know about how to plant broccoli seeds in your garden.
Broccoli florets are exceptionally healthful veggies. They’re rich in vitamins, minerals, fiber, and antioxidants that help regulate blood sugar levels, lower the risk of heart disease, alleviate inflammation, and prevent chronic illnesses.
Broccoli, or Brassica oleracea var. italica by its botanical name, is part of the cabbage family that is closely related to Brussels sprouts, cabbage, cauliflower, collards, kale, radishes, and turnips.
Broccoli’s main attraction is its large, edible flower head that is harvested just before it blooms. However, the stems and leaves are also tasty and tremendously nutritious. Use them like cabbage, chard, or kale.
All you require for growing broccoli from seed is a planting site that gets full sun and has rich, well-draining soil. Broccoli plants grow best in somewhat acidic soil with a pH between 6.0 and 6.8.
Applying used coffee grounds as mulch around the plants’ base adds nitrogen to the garden soil and slightly lower its pH.
Although most broccoli on the supermarket shelf is the Calabrese variety, there are dozens of unique cultivars to try growing at home. Here are a few of our favorite types of broccoli for home gardens.
How to Plant Broccoli Seeds
The best way of planting broccoli from seed depends on your growing climate, just as when you plant cucumber seeds. If you have mild spring weather, direct sow seeds anytime the soil temperature is warmer than 40℉. If you have short spring seasons that quickly turn into hot weather, consider starting seeds indoors.
For a spring crop, sow seeds indoors four or five weeks before your average last frost date, or direct sow two to three weeks before the last spring frost. Radishes growing season is similar.
Plant seeds directly in the garden bed for a fall harvest six to eight weeks before the first autumn frost so the broccoli heads mature in cooler temperatures.
Fill a seedling tray with seed starting potting soil. Sow seeds a quarter-inch deep, then loosely cover them. Gently saturate the soil without disturbing the seeds.
Keep the soil moist while the seeds germinate. The ideal temperature for germination is between 65-75℉. On average, broccoli seedlings emerge in eight to ten days.
Once the seedlings begin sprouting, place the tray on a south-facing windowsill where they get six or more hours of bright light daily. If you don’t have a sunny location available, use grow lights to prevent the broccoli seedlings from becoming elongated or “leggy.”
When to Plant Broccoli Seedlings
Broccoli seedlings should have at least six to eight true leaves before transplanting them into the garden bed.
Spacing between plants should be between 12-20 inches, depending on which type of broccoli you grow. Read the seed packet for variety-specific planting recommendations.
Plant seedlings outdoors two to four weeks before the last spring frost and protect them from below-freezing temperatures with a cold frame, floating row covers, or old blankets.
A week or two before planting broccoli seeds, cover the garden soil with several inches of organic compost, dark-colored mulch, or a sheet of black plastic to warm the soil.
Broccoli Plant Care
Broccoli plants thrive in well-draining, nutrient-rich soil. It’s beneficial to mix a plentiful amount of organic matter like compost or well-rotted manure with your garden soil several weeks before planting.
Although they tolerate partial shade, broccoli grows best in full sun with at least six hours of direct sunlight daily. Also, broccoli needs consistent soil moisture. Give your broccoli plants about two inches of water weekly and more during periods of hot or dry weather.
Broccoli plants are heavy feeders and benefit from regular fertilizing as they develop. When transplanting seedlings, the way to fertilize broccoli is to add one tablespoon of organic, all-purpose fertilizer to the bottom of the hole.
Fertilize the growing plants every four to six weeks according to the instructions on the product label.
How to Grow Broccoli from Seed in Pots
It’s okay if you don’t have a garden or raised beds at home. The way to plant cabbage seeds or growing broccoli from seed is also possible in a container garden. The technique for how to plant broccoli seeds is the same.
Choose a pot at least 12 inches deep, and allow 12-24 inches of width per plant. Use a container with several drainage holes at the bottom to prevent root rot and fungal diseases, as you would when you grow asparagus from seeds or any other plant.
Harvesting and Storing Broccoli
Broccoli heads are ready to harvest when they’re firm and dense. When to pick broccoli is to collect the main head is just before it flowers. Use a sterile, sharp knife or pruners to cut the main stem several inches below the head. Harvest immediately if you notice the flower buds opening.
Most broccoli varieties produce a second harvest of smaller side shoots for several weeks after cutting the main head. For the best results, harvest early in the morning when the buds are tight and firm.
Store homegrown broccoli in a perforated plastic bag in the crisper drawer of your refrigerator for up to one week. For more extended storage, freeze it for up to six months. Blanch the broccoli in boiling water before freezing.
Troubleshooting Pest and Disease Problems
The most effective defense against attacks from insects and plant diseases is to keep your plants healthy. Provide the proper amounts of light, nutrients, and water. Check regularly for signs of damage or distress.
Some of the most prevalent insects that damage broccoli include aphids, cabbage loopers, cabbage worms, flea beetles, and thrips.
Cover tender young seedlings with row covers to block bugs on broccoli and to keep insects from laying eggs on them. If you notice an insect infestation, spray all parts of the plant with an organic insecticide like neem oil or insecticidal soap.
Plant diseases like downy or powdery mildew and rust persist in damp conditions and typically spread through water droplets.
Run drip irrigation or a soaker hose to keep the leaves dry when watering and use proper spacing for adequate airflow. Treat affected plants with an organic copper or sulfur fungicide.
Growing broccoli from seed is amazingly straightforward, and the delicious results will have you hooked. Broccoli grows best in cool weather, making it an ideal spring and fall crop.
Ensure that your broccoli plants get full sun and plenty of water, and enjoy a bountiful harvest of tasty, nutritious homegrown broccoli florets. Don’t forget that the stems and leaves are edible, too.
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