Brussels sprouts (Brassica oleracea gemmifera) prefer a long (100-150 days) cool growing season, which means growing them in warm places like Arizona can be a challenge. Be that as it may, if you learn how to grow Brussels sprouts in Arizona (and the weather cooperates), the flavor of fresh-picked Brussels sprouts can’t compare to anything you buy at the store.
As the name suggests, Brussels sprouts were first cultivated in Belgium in the 16th century, and are an excellent source of vitamins and protein. This cold-loving member of the cabbage family produces miniature cabbage-like heads on a tall main stem surrounded by large leaves.
Fun Fact: the correct usage is Brussels sprouts,
not Brussel sprouts, even if you’re only referring to one sprout.
Want to learn how to grow Brussels sprouts in Arizona? Here are 5 tips:
1. Plant Brussels sprouts at the right time
Sow Brussels sprouts seeds 14 weeks before the first fall frost. Seeds sprout in 3 – 10 days at 70°F – 80°F. Seedlings grow best at temperatures between 60°F and 70°F.
In the low-desert of Arizona, we plant Brussels sprouts during warmer weather, and they mature during cooler temperatures. Start seeds outdoors from mid-August through the end of November, and plant transplants from September through the end of November.
2. Plant Brussels sprouts in the correct location
Once you know how to grow Brussels sprouts in Arizona, next year rotate the location for Brussels sprouts in your garden to prevent soil-borne diseases and the depletion of soil nutrients.
3. Give Brussels sprouts room to grow
Sow Brussels sprouts seeds ¼ to ½ inch deep and about 4 inches apart. Once seedlings have 2 sets of leaves, thin to 1-2 feet apart. Plant transplanted seedlings 1-2 feet apart.
For square-foot gardening, space plants 1 per square foot. If planting seedlings, do not let transplants dry out or get stunted in packs.
4. Care for Brussels sprouts correctly
Brussels sprout plants have a dense, shallow root system. The roots are close to the surface and are easily damaged.
- Water newly-planted sprouts thoroughly.
- Add 2-3 inches of mulch around plants to keep the soil evenly-moist and to prevent weeds.
- Water Brussels sprouts at the base of plants, not on the leaves.
- Pull weeds when small to avoid disturbing roots.
- At maturity, the plants are around 2 ½ feet tall. If your area is windy, stake Brussels sprouts at planting so not to disturb roots by staking later.
- Feed Brussels sprouts before planting with compost, and once or twice during the growing season with fish emulsion. I use this one from Amazon.
- Watch out for pests such as cutworms (use cutworm collars around young plants), aphids (spray off with a blast of water), and cabbage loopers (handpick or use Bt – I use this kind from Amazon).
5. Harvest Brussels sprouts at the right time
When growing Brussel sprouts in Arizona, harvesting begins as early as October and finishes up by March. Remember that cool temperatures sweeten the flavor of Brussels sprouts, but warm temperatures cause sprouts to be bitter and loose-leaved.
- Cut back on watering as Brussels sprouts near maturity.
- Keep an eye out for yellow leaves; this means nearby sprouts are maturing.
- Harvest Brussels sprouts when heads are small and firm, about 1 to 1 ½ inches in diameter.
- Grasp the sprout with 2 fingers, and twist it off the plant.
- Remove yellow leaves above developing buds as you harvest up the plants to give sprouts room to grow.
- Harvest plants continually for 6 to 8 weeks.
- Once buds form, if temperatures are beginning to climb or if you want to harvest all the Brussels sprouts at one time, pinch off the rosette (growing tip at the top of plant) about a month before the desired harvest. This directs the plant’s energy to increasing the size of the buds and they will develop all at once.
- Sprouts are best eaten fresh right out of the garden. Once picked, Brussels sprouts flavor declines as sugars turn to starch.
- If not eating the sprouts right away, store them covered in the refrigerator up to 1 week and wait to wash them until ready to eat.