Growing and Saving the Seed Of Brussels sprouts
Brussels sprouts are grown for their succulent flower heads or buds. They originated in the Mediterranean but were perfected in Belgium, possibly as early as 1200 AD. They need cool growing conditions to thrive.
Romans grew the ancient precursor to Brussels sprouts. The French introduced Brussels sprouts to the U.S. in the 18th century. A superstition once held that evil spirits lurked between the leaves of Brussels sprouts and that one had to cut an “X” at the base of each sprout before eating to release the spirits.
- Ideal germination temp is 50-75 F, but Brussels sprouts will germinate in soil temperatures as low as 40 F.
- Sow seeds ¼ to ½ inch deep.
- Seeds germinate in 7 to 10 days.
- Brussels sprouts require a fairly long growing season, about 80 to 100 days to maturity.
They love cool weather and can tolerate frost but not excessive heat.
In cold-weather climates, try planting very early in spring and again for a fall harvest.
Start seeds indoors several weeks before the last frost date and set plants out after the chance of hard frost has passed.
Brussels sprouts struggle once the temperature surpasses 75 F. Do your best to harvest before summer’s heat intensifies and ruins the quality of the sprouts.
Transplant into the garden at 2-foot spacing, optimally in the coolest part of the garden.
Keep plants well watered and well weeded, being careful not to disturb the shallow roots. Apply a thick layer of mulch around plants to keep the soil moist and cool. Remove yellowing lower leaves from plants to promote large sprouts.
For fall harvest, plant seeds mid to late summer in a shade house or other cool, protected location. Transplant in late summer when the extreme heat has died down.
Harvest continually starting from the bottom moving towards the top of the stalk. The tastiest Brussels sprouts are the ones harvested just after a touch of frost.
- Cabbage worms are a major pest of the cabbage family; a row cover will protect plants. You can also apply BTK (Bacillius Thurengiensis var. Kurstaki) a naturally occurring, organic approved bacterium, every 1 to 2 weeks.
- Use beneficial wasps to keep the population down.
- Interplant thyme with your plants; cabbage worms hate the smell!
- Brussels sprouts are biennial, which means that they will not flower until their second year of growth.
- They will readily cross with other brassica relatives that are flowering at the same time. It is best to isolate Brussels sprouts from other relatives by 1 mile, or use a bagging technique.
- The plants will die in temperatures below 20 degrees F. Mild-winter gardeners can mulch or protect with row cover to keep plants alive over winter. Northerners will need to dig plants up and place in buckets with soil covering the roots in a cool, dry location over winter. Replant in spring and allow plants to flower.
- When seed pods are fully dried, pick pods and place in a cloth bag. You will need to step on or hammer the seeds free from their stubborn pods. Separate seeds from chaff (leaf, pod and stem trash) and store in glass jars in the refrigerator.