When your Brussels sprouts (Brassica oleracea) are ready to harvest in autumn, you'll simply cut them from the stalk, starting from the bottom of the plant. This cool-season vegetable's ball-like "sprouts," resembling mini cabbages, are actually a collection of leaves that combine to form a hard mass -- so when you eat a Brussels sprout, you're packing in a lot of vitamins and protein into each bite. To get even more out of your Brussels sprout plant, you can also harvest and eat the large leaves surrounding the stalk.
When Sprouts Are Ready
Brussels sprouts will be ready to harvest as the warm summer weather begins to wane and the days get cooler. The exact time of year can depend on your growing zone, but in general, they tend to produce best at temperatures at about 65 degrees Fahrenheit. It takes about 90 to 100 days for Brussels sprouts to mature after seeding, depending on the variety, so check the seed or start packet for information about time to maturity for the variety you've planted.
When they're ready to harvest, Brussels sprouts will be about 1 to 2 inches in diameter and feel hard to the touch. If the sprout and the surrounding leaves are yellow, you've waited too long. The thick, sturdy, single stalk of a Brussels sprout plant produces sprouts starting from the bottom and moving up, so the harvest may be ongoing for several weeks. A single plant may provide up to 3 pounds of sprouts.
To harvest, start with the sprouts near the bottom of the stalk, as those will be ready first. Grasp the sprout -- including the leaf just under it -- in your hand and quickly press downward to break the sprout and leaf stem off the stalk. You can also use a garden knife to make a cleaner cut, making a cut that leaves the surface of the stalk flush. Cut off as many sprouts as are ready. When you cut off those sprouts, the sprouts above will continue to grow larger and eventually mature.
If you store your Brussels sprouts at 32 degrees Fahrenheit and about 95 percent humidity, they can keep for as long as two to six months.
Before cutting, wipe down your cutting tools with a solution of one part bleach to three parts water, to avoid spreading plant diseases.
You can eat the leaf that you removed from the plant when you cut the sprout -- just so long as it's not yellow. As you work your way up the Brussels sprout stalk and continue to remove sprouts, you can also remove any additional leaves and eat them. Young, tender leaves are best, as older leaves can have an off-flavor. Cut them off the stalk, flush with the stalk, using disinfected garden snippers or a garden knife. Cook the leaves like you would other winter greens, such as collards or kale.