How to Grow Broccoli
Broccoli is a cool season biennial that produces seed in its second season. It prefers rich soil that is slightly acidic, with a pH between 6.0 and 6.8, and has good organic matter. Good soil temperature for germination is 65-75° F. It is relatively tolerant to frost. Since it’s a heavy feeder, work in a few inches of rich compost before you plant. Start indoors 4-6 weeks before transplanting – Seed Depth: ¼ – ½ ” Plant Spacing: 18 – 24″ after thinned. Row Spacing 2 – 3′. You can also direct sow in garden about 4 weeks before last frost, but plant about 3 – 4″ apart before thinning to the 18 – 24″ spacing. Plant in full sun and keep soil moist. Allow seed 5-10 days to germinate. For a fall harvest, sow directly in the garden 12-14 weeks before first fall frost date.
Harvest when the buds of the head are firm and tight. Cut 5-10″ down on the stalk at a slant to promote the growth of side shoots. This will give you lots of smaller heads over a long period of time. Check the heads every couple of days because once the heads are no longer firm, the quality is not as good. Harvest the side shoots regularly to encourage further growth. Store at 32° F for 1-2 weeks.
Saving Broccoli Seeds
Suggested isolation is ¼ mile to prevent cross pollination. Barriers such as trees or buildings can allow for closer distances. Broccoli produces seed in its second year, so shelter from the cold with row covers, cold frames, or tunnels. When seed pods are dry, handle carefully. Use a thin screen to help clean the seed. Broccoli seed is viable for about 3-5 years if kept cool and dry.
- Cabbage Worms
You can sow mint, oregano, thyme, or wormwood near the broccoli to repel the egg-laying cabbage butterflies. There is also a botanical insecticide available called Pyrethrum which helps against the cabbage worm. Also, simply picking off the cabbage worm on the plants can be very effective, so check your plants daily.
- Club Root
Leaves that are wilting and turning yellow, young plants that are showing signs of decay, and/or old plants that have stopped growing are all signs that your broccoli may be fighting club root. If you look at the roots, you will find golf ball size bulbs instead of a healthy root system. Immediately dig up and discard the infected plants. This fungus can be discouraged by keeping the pH balance high at 6.8 or higher, improving soil drainage and controlling weeds. Water the soil before sowing with a spray made of boiled Rhubarb leaves to help prevent club root. Wood ashes can also be helpful.
- Head Rot
Leaf discoloration and decay on leaves where wilting and white growth begin to appear may be suffering from head rot. Proper management of weeds and insects can help reduce occurrence of this disease. Also, crop rotation, good air circulation, and well-drained soil can also be helpful. Avoid wounding of the roots during cultivation. Also, make sure to maintain proper calcium and boron levels in the soil.
- Pole Beans