A long-time favorite variety, Waltham 29 broccoli plants were first developed in 1950 by the University of Massachusetts research farm. Waltham 29 broccoli is a compact, robust, cold-resistant variety, growing 24-30 inches tall and producing green heads that are four to eight inches wide. Plants also produce some side shoots for continuous harvest.
GROWING INSTRUCTIONS
Broccoli is a cold-hardy crop that does very well with spring and fall plantings. It is a nutritional powerhouse that requires attention and space, but the fresh florets are worth every bit of effort.
Start broccoli seeds indoors about 4-6 weeks before the last frost date. Use a seedling flat and a high-quality seed starting mix. Plant a few rows per flat, a couple seeds every 10 cm. A shallow depth of 1 cm is perfect for the small seeds. Bottom water, but don’t let the trays sit in standing water. Put the seeds in a warm place and provide plenty of light once the sprouts germinate.
Broccoli needs lots of nutrients to grow strong and produce hefty heads. When sprouts show their first true leaves, apply a weak dose of liquid fertilizer, like fish emulsion or compost tea.
Thin out sprouts when they start crowding, up to 30 cm. Transplant into a small pot if the flats are outgrown, but don’t be afraid to transplant into the garden 2-4 weeks before the last frost. Broccoli is quite hardy and will tolerate cold temperatures without a problem. After all, the sooner they make it to the garden, the quicker they can get established. But make sure to progressively harden them off first.
Slowly acclimate the young plants to the sun and outdoor elements. When ready to transplant, put them in their permanent places 30-60 cm apart. Allow space for the florets to grow tall and wide.
Broccoli can take anywhere from 50 to 90 days until harvest, depending on the variety. Fertile soil and regular feeding throughout the season will contribute to a faster growth rate, and ultimately improve the quality of the final product.
QUICK FACTS
- Native to the northern Mediterranean, broccoli was first cultivated in 600 BCE in ancient Roman times. The popularity of the vegetable had spread to most of Europe by the 1700s and was cultivated in America beginning in the 1800s.
- Broccoli is a cold-hardy vegetable, the best results are with spring and fall crops. They can still perform well in partial shade during the hot summer months.
- The majority of broccoli cultivars can withstand frost, making them an ideal crop for colder conditions.
- Broccoli seeds will remain viable for 4 years if stored in a cool, dark place, ideally between 4 and 10⁰C. After that, the germination rate may start to go down.
