How to Grow Brussels Sprouts in Arizona (Low Desert Guide)

If you’re a beginner or want a guaranteed harvest, I’d skip them. That’s why they’re on the skip list in my easy fall vegetables for mild winters. I still grow a plant or two most years. A colder winter helps, but my harvest is small. If you want to try them, the timing below gives you the best shot.

Brussels Sprouts in the Low Desert at a Glance

• Start seeds indoors from July through September.
• Plant transplants out from September 15 through November, once nights start to cool.
• Give each plant 1 to 2 square feet in a raised bed.
• Choose a variety with the shortest days to harvest you can find.
• Watch for cabbage worms early in the season and aphids at the end.
• Harvest in spring. Top the plants about a month before you want to pick.
• If you miss the November window, wait until next year.

Are Brussels Sprouts Worth Growing in Arizona?

It depends on how much space you have. A Brussels sprouts plant takes up a spot in the bed for most of the cool season. In my garden, growing broccoli in the low desert gets me far more food from the same space, and so does the way I grow kale.

Brussels sprouts love cool weather, and cool temperatures sweeten the flavor. They like it much colder than we get here.

If you have room and like to experiment, grow one or two plants. If space is tight, plant broccoli or kale first.

When Should I Plant Brussels Sprouts in Arizona?

Plant Brussels sprouts while it’s still warm so they mature during the coolest part of the year. In the low desert, start seeds indoors from July through September and plant transplants out from September 15 through November. September 15 is the earliest date, so if nights are still hot, wait until they start to cool. You can see where Brussels sprouts fit with everything else on my Arizona vegetable planting calendar.

I usually start my seeds in July or August and plant out in September or October. One year I planted two Brussels sprouts side by side, one in September and one in October. They did about the same.

Starting Brussels sprouts from seed

Start seeds indoors about 8 weeks before you plan to set plants out. Seeds germinate in 3 to 10 days at 70 to 80°F (21 to 27°C), and seedlings grow best at 60 to 70°F (15 to 21°C). It’s far too hot outside for seedlings in July and August, so I start them inside, on the same schedule as the other fall crops in when to start seeds indoors for low desert vegetables. If you’re new to it, begin with how to start seeds indoors.

Brussels sprouts transplant easily, which is why they’re on the transplant side of my list of seeds or transplants for each crop. I’ve grown them from my own seedlings and from store-bought transplants. Before planting, harden off seedlings for about a week so they can handle full sun, and don’t let transplants dry out or get stunted in their pots. Then follow my steps for planting transplants.

What if I missed the planting window?

If November has come and gone and nothing’s planted, wait until next year. Brussels sprouts planted after the window won’t have enough cool weather to size up before spring heat arrives. Use the space for something faster, like broccoli, kale, or bok choy.

Which Brussels Sprouts Varieties Grow Best in Arizona?

Look for the shortest days to harvest you can find. Our cool season is short, and a variety that matures faster has a better chance of filling out its sprouts before the heat. These are the Brussels sprouts seeds I plant.

Where Should I Plant Brussels Sprouts?

I grow mine in raised beds. Give Brussels sprouts at least 6 hours of direct sun.

They need fertile, well-draining soil rich in compost. Before planting, mix compost into the bed. If you’re filling a new bed, start with the best soil for raised bed vegetable gardening.

Rotate where you plant them each season. Avoid spots where broccoli, cabbage, cauliflower, or kale grew last year. Rotation helps prevent soil-borne disease and keeps one crop family from using up the same nutrients year after year.

How Far Apart Should I Plant Brussels Sprouts?

In my raised beds, I plant one Brussels sprouts plant per 1 to 2 squares, laid out with the grid from my square foot gardening tips. If you plant in rows, space transplants 1 to 2 feet apart.

Direct sowing isn’t the best option here, but if you try it, sow seeds 1/4 to 1/2 inch deep and 4 inches apart. Once the seedlings have two sets of true leaves, thin them to 1 to 2 feet apart.

Young plants leave open space around them for the first few weeks. I like to fill it with bok choy, a quick brassica that’s ready long before the sprouts. These tips on how to grow bok choy cover spacing and timing.

How Do I Water and Feed Brussels Sprouts?

Brussels sprouts have shallow, dense roots that are easy to damage. Water new transplants thoroughly. Then follow the tips for mulching your vegetable garden and add 2 to 3 inches to keep the soil cool and moist.

Water at the base of the plant and keep water off the leaves. Pull weeds while they’re small so you don’t disturb the roots. If you’re not sure how much to water, start with the best way to water raised bed gardens.

Feed the bed with compost before planting. During the season, feed once or twice with fish emulsion, following how and when to use liquid organic fertilizer. I use this fertilizer from AgroThrive.

Plants reach about 2 1/2 feet tall. I haven’t needed to stake mine much. If your garden gets a lot of wind, put a stake in at planting time.

What Pests Attack Brussels Sprouts in Arizona?

Cabbage worms show up early in the season, when cabbage moths (the small white butterflies) lay eggs on young plants. Handpick the green caterpillars or use Bt. I use this Bt from Amazon, and the same steps for how to get rid of cabbage worms work on any brassica. Protect new transplants from cutworms with a collar around the stem.

Aphids show up as the season ends and the weather warms. They tuck into the folds of the sprouts and leaves. Blast them off with a strong spray of water, or follow my steps for getting rid of aphids, including when to ignore them.

When and How Do I Harvest Brussels Sprouts?

My harvest comes in spring. Sprouts form along the stem from the bottom up, and the lowest ones mature first. Pick them when they’re firm and 1 to 1 1/2 inches across, before warm weather turns them loose and bitter. Twist them off with your fingers. Cut back on watering as plants near maturity.

Yellowing leaves are a sign the sprouts next to them are maturing. Remove yellow leaves above the developing sprouts as you go. If the weather stays cool, you can harvest over 6 to 8 weeks.

Topping Brussels sprouts

About a month before you want to harvest, or as soon as temperatures start to climb, I top my plants. I cut off the growing tip at the top of the plant, right above the top sprouts. That sends the plant’s energy into growing the sprouts nice and fat instead of growing taller. It works like harvesting a broccoli head, when the plant sends its energy out to the side shoots. It also helps the remaining sprouts mature around the same time. We don’t eat the tops.

Storing Brussels sprouts

Fresh-picked Brussels sprouts taste best eaten right away. To store them, refrigerate unwashed sprouts for up to a week and wash them right before cooking. Our favorite way to eat them is roasted in a cast-iron pan with bacon and honey.

For the bigger picture on growing food here, start with my post on how to grow a vegetable garden in Arizona.

Growing Brussels Sprouts FAQs