Brussels sprouts, named because they were first cultivated in large numbers near Brussels in Belgium, are the aristocrat of the cabbage family. They look like tiny cabbages but have a much more delicate flavor. They are particularly delicious when sprinkled with almond flakes that have been lightly fried in butter!
More commonly called Brussel sprouts, these mini-cabbages take quite a long time to develop and mature. It will usually take between 90 and 120 days after planting brussels sprout seeds for the heads to mature and become firm and compact. A reliable rule of thumb is to harvest them when they are about 1 inch in diameter (2.5 cm).
How Do You Know When Your Brussel Sprouts Are Ready to Harvest?
Even though Brussel sprouts are a cultivar of cabbage in the Brassicaceae family, the heads of the plants that we eat, grow in a very different way to cabbage.
Instead of the head forming at the top of the plant, the bud-like heads of these sprouts form in the leaf axils of a long, spiral stem. They start forming at the base of the stem and then develop upwards.
Varieties range in height from 18 inches to 3 feet (46 cm to close on a meter.) Tall types have less crowded sprouts growing up the stem.
The plants don’t start producing sprouts until the stalks are almost full height. One Brussels sprouts plant can produce more than 100 sprouts over 2-3 months!
Brussels sprouts are a cool-season crop and, according to the Colorado State University and other extension projects, are sweeter in taste when we harvest them after a mild freeze. One to two frosty nights are recommended. This is known as cold sweetening.
So, even though it is common to harvest them in the fall, an early winter harvest can be advantageous.
Additionally, whichever variety of Brussels you grow, it is always best to harvest them on a cool day.
If you are growing brussels sprouts in a warm climate, hot weather may result in puffy heads that are not compact. You can still harvest them and cook them, but they will lack flavor.
So, how do you know when your Brussel or Brussels sprouts are ready to harvest? Whether you decide to sow seeds directly in the ground in your veggie garden or to start the seed indoors, the guidelines will be the same.
Check the Seed Packet
Presuming you have started your plants from Brussel sprout seeds, you will be able to see from the seed packet how many days it should take to harvest. Of course, it will depend on the variety of Brussels sprouts planted, and whether they are hybrids or open-pollinated types.
The most popular types for home vegetable gardening are dwarf hybrids.
Here are some time-frame examples:
- Widgeon 120 days
- Rubine 105 days (open-pollinated heirloom plants)
- Jade Cross and Prince Marvel 90 days
- Royal Marvel and Oliver 85 days
- Bubbles 82 days
Of these, the most popular are Jade Cross and Prince/Captain Marvel hybrids.
Jade Cross hybrids are shorter – 24 inches to around 30 inches (61-76 cm). The sprouts are firmer and rounder and they are nicely spaced on the stem for maximum aeration.
Oliver, and the Marvel hybrids, are ideal for cold harvest conditions.
Check the Diameter of the Sprouts
Generally, Brussels sprouts should be at least an inch in diameter before you harvest them. Some grow to about 2 inches (5 cm) in diameter.
If they get too big, they will tend to start cracking and will become bitter in taste.
Check the Color of the Leaves
It’s important to harvest Brussel sprouts before the leaves of the plant turn yellow. Usually, this change in color corresponds with the maturity of the sprouts.
Often growers remove any leaves when they start to go yellow. This is what most commercial growers do to accelerate maturity.
In any case, if you don’t remove the leaves before you harvest your sprouts, it’s a good idea to remove them after the first harvest. This will stop them from drawing energy that should go to the remaining sprouts at the top of the plant.
What Happens If You Don’t Harvest Brussel Sprouts?
Why wouldn’t you harvest the Brussel sprouts you have been tending for so long? Maybe you’ve just got so many sprouts you don’t know what to do with them.
This is a common problem when people succeed with their vegetable gardening efforts at home. It’s especially common when they sow seeds, because of the potential number of plants that can be propagated.
I’ve done a bit of (not literal) digging, and some home gardeners say that because Brussels sprouts are a biennial plant, they will flower and set seed in their second year. It’s difficult to know since most people treat them as annuals and remove the plants after the growing season.
If you want to experiment, try pinching off the top of the plant at the end of the growing season, and see what happens.
If you simply delay the harvest, the sprouts will become tough and they will lose their delicate flavor. The tightly wrapped leaves will also start to loosen.
How to Harvest Brussel Sprouts?
Harvesting Brussels sprouts is easier than growing Brussels sprouts! Once you know that it’s the right time to pick the sprouts by twisting each one off the stalk, get yourself a sharp knife or secateurs.
That said, there is a simple process to follow.
How to Start Harvesting Brussels Sprouts
Start at the bottom of the plant, and either break the sprouts off the stalk or cut them off with your knife. If they aren’t all developed fully in size, pick them progressively, leaving those at the top of the plant a little longer.
If you remove the terminal buds from any plant growing in your garden in the growing season, before you expect a heavy freeze, the sprouts will develop more rapidly. These are the central buds at the top of the plant.
Removing the terminal bud will also enable you to split your harvest into more than two sessions, depending on the variety.
You will be able to split the harvest of European-type hybrids like the Marvel varieties into two sessions. The American hybrids develop more slowly, so you might end up harvesting brussels sprouts from one plant as many as four or five times.
It doesn’t take the sprouts higher up the stalk long to catch up, so keep checking your plants every couple of days.
As the weather gets colder, the plants will stop producing new sprouts. But you can extend the season by using row covers to protect the plants from frost.
How to Harvest Brussel Sprouts to Make Them Last Longer
If you harvest your Brussel sprouts on the stalk, they will stay fresh a bit longer than individual sprouts. But, because the sprouts develop from the bottom of the plant upwards, you must be sure those at the top of the plant are sufficiently well developed.
Cut the stalk just above ground level, or pull the entire plant out of the ground and cut off the roots.
Plants have relatively shallow root systems. Even though we plant Brussels sprouts seed about ¼ inch deep, you will find that most roots will be between 18 and 36 inches deep at harvest.
Should You Wash Brussel Sprouts after Harvesting?
Brussel sprouts aren’t usually dirty when you pick them, but you should always wash them before eating them. This will get rid of any sand or tiny insects that are trapped in the outer leaves.
If you pop them into the kitchen sink or a bowl of cold water, any sand or sediment will sink to the bottom. Be sure to let them dry thoroughly before you store Brussels sprouts.
However, many people store them unwashed wrapped in a moist towel placed in a perforated plastic bag in the vegetable crisper drawer in the fridge.
Can You Eat Brussel Sprouts Immediately after Harvesting?
Brussel sprouts are at their best immediately after harvesting.
They are a highly perishable vegetable, so if you aren’t going to eat your crop immediately, keep the sprouts refrigerated at about 32-42°F (0-4°C). If you can control the environment, aim for 95% humidity to keep them moist.
You can store Brussels sprouts in the fridge for about a month to five weeks. According to a Brussels sprouts fact sheet released by the Utah State University (USA), refrigerating your Brussels immediately will prevent the loss of moisture and will stop yellowing.
If you store them above 50°F (10°C), they will lose their color very quickly.
Freezing your sprouts is another excellent option. All you need to do is trim, wash, and blanch them in very hot water. Then cool them down immediately in cold water for another three minutes.
Harvesting Brussels sprouts isn’t difficult. You can start your harvest in the fall and continue until early winter.
The key to success is to make sure that the sprouts are fully developed, but not too large.
Our gardening tips provide you with useful details that will help you identify when your Brussel sprouts are ready to harvest. If you follow our guidelines, you will be sure to get a good crop that is at its flavor peak.
Read more about growing Brussels sprouts in our article, When to Plant Brussel Sprouts.