How To Grow Organic Broccoli?
WHEN TO PLANT
- Broccoli is a cool weather vegetable and grows best at temperatures between 60-65°F.
- When you’re growing broccoli, seeds can be sown directly into the garden up to 2 months before your last frost date if protected from cold temperatures with row covers.
- For growing broccoli, once daytime temperatures have reached a steady 60°F or warmer, consecutive plantings can be direct-seeded into your garden up until summer.
- To avoid crop damage from severe temperature fluctuations, we recommend planting and growing broccoli indoors 5-6 weeks before your last frost date.
- For a fall harvest, plant seeds directly into your garden up through early summer or up until temperatures reach a steady 75°F and above.
WHERE TO PLANT
- Broccoli likes full sun in the spring
- When planting in early summer for a fall crop, find a place that provides some afternoon shade such as behind corn, or another tall crop
- Artificial shade can also be used
- A thick cover of mulch will keep your soil cool. These measures (afternoon shade/mulching) will help your broccoli not to bolt (go to seed)
PREPARING THE SOIL
- Broccoli is a heavy user of nitrogen. In the fall, work into your soil generous amounts of organic matter (such as autumn leaves) and manure
- The pH level for growing a healthy broccoli crop needs to be around 7.0 Using lime will help to raise the pH levels if they are low
SEEDS AND GERMINATION
- Your broccoli seeds will germinate best at temperatures 60-70°F
- Seed Viability: 3 years
- Days to germination: 4-5 days
GETTING STARTED INDOORS (and transplanting)
- Start broccoli seeds indoors 5-6 weeks before your last frost date
- While indoors you will need to transplant seedlings one time to a larger pot or flat before transplanting to the garden
- Harden off one full week before planting in the garden
- Transplanting broccoli when they are the proper size is critical for preventing premature heading. Transplant when seedlings are 6″ tall and have 2-4 leaves.
PLANTING/GROWING (Planting seeds directly into the garden)
- Space rows 24” apart and place plants in rows 18-24” apart
- Plant broccoli 1” deeper in the garden than what they were in the pot or flat
- An extended cold spell of 50-60°F days and 30°F nights can affect your crop by producing small, underdeveloped heads called ‘buttons’. Use row covers if needed
- Monthly supplements of compost tea and fish emulsion, along with a liquid organic leaf spray will help to feed your nutrient hungry broccoli
- Presoak the soil before planting indoors, or outdoors
- Broccoli needs about 1” of water a week. Adjust for more in arid areas
COMPANION PLANTING / ROTATION
- Plant broccoli away from where brassica was growing the previous year; this will discourage brassica pests from proliferating
WHEN TO HARVEST
- As the weather warms past 75°F, watch your broccoli very carefully. Harvest before the head blooms when the flowers are still tight
- With a sharp knife, cut stem at the point where the top branches begin
- After the harvest you should have a secondary harvest of small florets or side-shoots growing up from the stem
- Broccoli will last up to 2 weeks in the refrigerator
- Blanching or steaming, then freezing, is the best method for preserving it’s natural flavor and color
- Other methods include pickling or preserving in oil
COMMON PESTS AND PROBLEMS
- Overhead watering will help detach insects from the plant
- Controlling nitrogen levels keep the aphid numbers down; high levels of nitrogen have been shown to increase aphid population
- Using compost or straw mulches will significantly reduce the amount of fly larvae hatched directly into the soil
- Floating row covers used as soon as the plant emerges or right after transplanting will prevent larvae hatchings
- Clubroot (a fungus that attacks the roots) can be controlled by keeping soil pH at 7.2
- Rotating your crop every year (planting in a different location than the previous year) will help to eliminate pest and disease issues.
- More information to come!