Brussels Sprouts

Brussels sprouts: prehistoric weapons, baby cabbages, or healthy garden addition?

Many years ago, my mother showed up for a Thanksgiving dinner armed with what looked like a medieval weapon. Having never seen the unopened flower buds still attached to the stalk, it confused me, at first. If you have never seen Brussels sprouts growing on a stalk, you are in for a surprise!

Brussels sprouts (Pikist)

A little history

Brussels sprouts (Brassica oleracea) were first grown as far back as the 5th century throughout the Mediterranean. The Romans liked them, so they moved around quite a bit. They were widely grown in Belgium, back in the 16th century, hence the name Brussels. These plants prefer cooler, coastal weather, so they are a winter crop in California. Lucky for us, a touch of frost actually makes Brussels sprouts sweeter! In fact, California grows Brussels sprouts on several thousand acres each year.

How to grow Brussels sprouts

Brussels sprouts seeds can be planted in the Bay Area in July and August, and transplants can be put in place as late as September. Brussels sprouts and other cole crops love growing in raised beds, with their nice loose soil with plenty of nutrients. (It makes weeding a lot easier, too!) These plants do not perform well in poor soil. Each plant will need an area 2 to 3 feet square, so thin accordingly. Seeds should be planted 1/2 an inch deep and watered well. Keep the soil moist until germination occurs. A nice light mulch can help keep that moisture in place. If you are placing transplants, be sure to dig the planting hole large enough to accommodate the root ball plus the stem, up to the first set of true leaves. Mud them in by watering thoroughly, to eliminate any air pockets, and water every day for the first week. After that, allow the soil to dry out between waterings to prevent fungal diseases.

Pests and diseases of Brussels sprouts

Like other members of the cabbage family, Brussels sprouts are host to many different pests: earwigs, cutworms, flea beetles, beet armyworms, crickets, cabbage aphids and cabbage maggots, whiteflies, loopers, imported cabbageworm, harlequin bugs, nematodes, slugs and snails, thrips, wireworms, and diamondback moths are the more common pests here in California. Brussels sprouts diseases include downy mildews, powdery mildew, bacterial leafspot, bacterial soft rot, while mold, verticillium wilt, phytophthora root rot, clubroot, and ring spot (black blight). Clearly, with so many fungal diseases threatening our Brussels sprouts, moisture is a factor. Brussels sprouts should be on a 2 to 4 year crop rotation to break these disease triangles. Research shows that intercropping Brussels sprouts with fava beans has been shown to reduce pest damage significantly.

Caring for Brussels sprouts
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As your plants grow and start to produce buds, break the lower leaves off, over a period of a few weeks, starting from the bottom of the plant. Brussels sprouts are susceptible to sunburn damage and will bolt if temperatures get too high. You can help prevent these problems by covering them with a 50% shade cloth or a double layer of row covers. You can also plant them in a location that is protected from direct sun in the hottest part of the afternoon. This isn’t much of a problem as we get into winter.

Harvesting Brussels sprouts

Your crop is ready for harvest when the sprouts are 1 to 2 inches in diameter, which usually takes 80 to 120 days, depending on all the usual variables. Buds tend to ripen from the bottom of the plant to the top. Commercial growers pinch off the tops of their plants when the buds are 3/4 inch in diameter to create a uniform crop. You can expect to harvest 2 pounds of produce from a  single stalk.

Brussels sprouts (Media Mike Hazard) CC BY 2.0

​One of the most common reasons people dislike Brussels sprouts is because of the way the plants have been handled. Overcooking Brussels sprouts makes them gray, mushy, and bitter. Fresh Brussels sprouts are sweet and tender.

​Try adding just one Brussels sprout plant to your garden this fall and share the rest of your seeds with family and friends!