Some people love Brussels sprouts while others hate it. I think they are a wonderful plant to grow in your garden. You don’t need a lot of space and can grow Brussels Sprouts in pots with a little care.
1. Pick the best time to plant
Brussels Sprouts are an annual plant with a relatively long growing cycle. While these plants can prosper in virtually any climate, they do best with cold weather. Sprouts will thrive when temperatures are somewhere between 45 and 75 degrees.
That’s a pretty generous temperature range, so you have a couple of choices on when to start planting. The best choice for you will ultimately depend on the climate.
Those who live in regions with very cold winters will want to start indoors. You can germinate seeds a few weeks before the last frost. Once the weather starts warming up, you can transplant to a container outside. In these climates, an early start will result in a harvest in the early fall.
If you’re in a milder climate with only occasional freezes, you can start planting much later. Plants do well when planted early to mid-summer. The Brussels sprout plant will do most of its vegetable production in the fall. Thus, you can harvest late fall or early winter.
Finally, we have areas with warm winters. Gardeners in the South rarely experience frost. So, plants can start very late in the summer. Planting too early in these regions can result in bolting and development issues. It’s best to aim for late-summer planting to reap the rewards of your harvest in winter.
2. Understand how long it takes to grow
There’s a reason why you don’t see too many gardeners attempting to grow Brussels sprouts. They have a very long growing cycle.
On average, you can expect at least 100 days of care until you can harvest a mature Brussels sprout. However, many factors determine growth rates. Everything from climate to sun exposure will impact how long it takes.
With some cultivars, it can take double or triple the average time. In those cases, you’re looking at nearly a year to harvest.
Luckily, that’s not going to be the case with most gardeners. Either way, it’s important to plan ahead and prepare yourself for a lengthy growth cycle.
3. Choose the right container
The first step in your gardening journey is to choose a suitable pot.
Brussels sprouts are a bit unique in terms of size and composition. Most people aren’t familiar with how they grow. While they look like miniature cabbages, these sprouts grow on tall stalks.
Stalks can get up to 30 inches tall. The root system can dive pretty deep, too. But, the plant doesn’t get very wide. On average, a mature plant will only be about 8 to 12 inches wide.
This is good news. It means that you can successfully grow Brussels sprouts in manageable containers. You don’t need an enormous pot to see success.
For a single plant, a 5 to 7-gallon pot is ideal. It needs to be at least 12 inches wide to accommodate the plant’s width. Plus, it should be at least 12 inches deep to support the roots.
If you go with a larger 15-gallon pot, you should be able to keep 2 or 3 in a single container.
When it comes to material, the sky’s the limit. The plants do just fine in lightweight plastic pots. As long as the container isn’t made of brittle low-quality plastics, you’ll have no problem.
Terracotta pots work well, too. The terracotta clay is naturally porous. As a result, it holds onto moisture very well. This can be quite beneficial to the moisture-loving Brussels sprout plant.
4. Prepare the container for planting
If you get your pot from a local gardening center, there’s not much you have to do to prepare it.
However, DIY containers may need a bit of work.
The most important thing is to ensure that the pot drains water well. Turn it over and take some time to drill holes in the pot.
Use a relatively large drill bit to create sizable holes. The drainage slots should be big enough to let water out. But, they also have to be small enough to prevent soil from falling out. If you think the holes might be too big, you can use some gravel or mesh at the bottom of the pot for soil support.
Add several holes around the perimeter of the pot’s bottom. Put some in the center, too. You need a decent number of holes in the pot to prevent issues like root rot and fungal diseases. It may even be worth adding a few additional holes in your store-bought pots.
5. Add support to the container
Because these plants get so tall, additional support is a must.
Many gardeners think you don’t need support at all. When you look at a mature plant, it’s easy to see why. The stalks are quite girthy. But at the end of the day, they’re still softer than bark.
We want the individual Brussels sprouts to be as big as possible, right? Well, the weight of large sprouts often causes the stalk to give in. This is especially true late in the growing season. The last thing you want to deal with is a damaged plant right before you go to harvest.
Adding some container supports can help to take the weight load off the stalks and keep your plant upright.
There’s not much you have to do to prepare pots. You can drive simple stakes into the soil once the plant gets bigger. More on that later. Tomato cages work well, too.
If you want some additional support, you can attach the support to the pot beforehand. Add a cage or pyramid-style trellis to the pot before you add the soil. The soil will compress around the support to provide more stability when you need it.
6. Plant the seeds or seedlings
There are two ways to start your Brussels sprout plant. You can choose to germinate seeds or use a young seedling.
If you go the seed route, you will likely need to start indoors. Start seeds a few weeks before the last frost so that the seedlings are ready once the weather warms up.
You can use a seed tray or sow the seeds directly in the pot. The choice is yours.
Fill the container with loose, well-draining soil. Prior to planting, it’s good to amend the soil with some organic compost. This extra step will ensure that the soil has beneficial nutrients your plant can use to grow. Otherwise, a seed starter mix works fine, too.
Bury seeds about half an inch deep. You can scatter the seeds evenly over the soil to increase germination rates.
Cover the seeds for added humidity and put the container in a warm spot. Brussels sprout seeds germinate in temperatures above 45 degrees. In roughly 7 to 12 days, you should start to see little sprouts breaking through the soil.
Planting seedlings is a bit easier and requires less planning. You can start your plant after the first frost and put your pots outdoors.
Delicately remove the seedlings and place them in your soil. For 5 to 7-gallon pots, use a single seedling per pot. For larger containers, give the seedlings about 12 to 14 inches of space.
Whether you choose seeds or seedlings, give the newly planted Brussels sprout a good watering.
7. Give the required sunlight to the plants
For optimal growth, put your Brussels sprout plants in full sunlight.
At the very minimum, these plants need 6 hours of sunlight every day to stay healthy. However, more is always welcome. Because the plant grows in cooler climates, excess heat isn’t a huge concern.
Place the pots on the south side of your house so that they can take advantage of the sun’s rays all day long. Avoid putting them near shade or any structures that will block the sun. The more sun your plant gets, the better off it will be.
More sun can result in larger yields and better overall health. Though, increased sun exposure could warrant more frequent waterings.
8. Water the Brussels sprouts plant
Watering a Brussels sprout plant is a balancing act. You have to provide enough water to keep the soil moist. But, you must also avoid overwatering to prevent fungal diseases and root rot.
Generally, these plants will require at least an inch of water every week. This is equivalent to about 16 gallons. Some plants may need a much as an inch and a half. It all depends on the amount of sun they get.
This weekly water allowance should cover several watering sessions.
The goal is to keep the soil moist at all times. Brussels sprout plants will tolerate some light drying in the early stages of growth. But once the plant is forming heads, you need to be vigilant about watering it.
Maturing plants will use up far more energy to create those little sprouts. It’s a make or break time for the plant. Keep the soil moist so that it has all the fuel it needs to develop the vegetable.
One great way to keep the soil moist is to add mulch. Covering the soil with organic mulch will help to slow down water evaporation. Leave several inches of space around the base of the plant to prevent fungal problems.
9. Thin the Brussels sprouts seedlings
When you start your plants from seeds, thinning is a necessary step.
In the early stages, we want to germinate as many seeds as possible to make sure that you have a healthy one to develop further. After several weeks of growth, those seeds will start to get crowded.
Thinning helps to eliminate clutter. Seedlings can stop fighting each other for nutrients, allowing a single plant to flourish.
The best time to thin Brussels sprouts is when they’re about 4 to 5 inches tall. Take a look at your seedling clusters and find the one that looks the healthiest. Then, remove the rest.
You can gently pull the other sprouts out of the soil. Cutting them at the base works, too. This is the preferred method if you’re worried about damaging the roots of the seedling you want to keep.
Thin the herd so that each plant is 12 to 14 inches apart.
Transplanting may be necessary as well. You might want to do this if you grew the seeds in a shallow tray.
Don’t transplant immediately after thinning the plant. It’s best to give the seedling some time to recover and spread its roots a bit. Wait until the seedling is roughly 5 to 7 inches.
After preparing the pot, gently remove the seedling. Create a hole in the soil that’s about the same size as the root cluster. Put the seedling in the hole, cover it up with soil, and give the transplant a good watering. Be careful not to damage any of the roots during this process.
10. Fertilize the Brussels sprouts plant
Fertilization isn’t always necessary. If you amended the soil with compost before planting, there should be plenty of nutrients to support the plant as it grows.
That said, many gardeners like to add fertilizer to help the Brussels sprout flourish even more.
Only apply a single application of fertilizer. Do this about 3 weeks after planting. If you transplanted the plant to a bigger pot, wait 3 weeks after the transplant.
You don’t want to overdo things here. While the plants like nitrogen, too much of it could be detrimental. Excess nitrogen levels will result in more foliage. The plant diverts its energy to get bigger rather than producing fruits. That’s the exact opposite of what you want.
Apply only one fertilizer application early on. That will be more than enough to help the plant reach its full potential.
11. Prune the Brussels sprouts plant
Like fertilization, pruning isn’t necessary to keep the plant healthy. That said, the practice can provide you with a bigger yield.
Pruning removes excess growth so that the plant can focus its energy on vegetable production.
Learning how to prune the Brussels sprout plant is all about understanding its development cycle. When the plant starts to create sprouts, they will appear close to the base. Over the course of several weeks, more sprouts will appear going up the stalk.
The best time to start pruning is right when you see those first sprouts popping up. Use hand pruners to snip off 6 to 8 lower leaves. Cut as close to the stalk as possible.
Leave the larger leaves towards the top of the plant intact for now. They will help collect sunlight for the plant.
Trimming those lower leaves can result in vigorous growth for the sprouts.
Continue pruning a few lower leaves every week as new sprouts appear. Work your way up the stalk of the plant until the sprouts are almost ready for harvest.
About three weeks before the final harvest, you can cut off the top of the plant. Use shears to cut straight through the top part of the stalk. Do this just above the higher leaves.
This final pruning task is something that many commercial farmers do. It gives the plant a final push to develop the sprouts. It may even help all of the sprouts mature at the same time.
12. Add support to the Brussels
As I mentioned earlier, you might have to stake your plant once it gets taller.
Not all gardeners will go this extra mile. But, we want to produce a tall stalk with tons of sprouts. Supporting the plant with stakes will make that possible.
You can support the plant in a couple of different ways. The simplest method is to use individual stakes. Drive a metal or wooden stake into the soil next to the base. Be careful not to damage the roots in the process. Push the stake to the bottom of the pot and compress some soil around it for added stability.
Now, use some garden twine to tie the stalk to the stake. It’s as easy as that.
Tomato cages and traditional trellises are suitable as well. Just tie the stalk to one side to prevent it from toppling over.
13. Harvest the Brussels sprouts from the plant
Brussels sprouts are gorgeous when they’re ready to harvest.
The tall stalks erupt with bright green sprouts. You’ll know when it’s time to harvest when the sprouts are bright green and 1 to 2 inches in diameter.
As I said earlier, sprouts grow from the bottom up. As a result, the lower sprouts can mature faster. You can use pruning techniques to manage maturation rates. Or, you can pick them off as they’re ready.
To remove individual sprouts, simply twist the heads off with your finger. You can also cut them to separate the vegetable from the stalk.
If you’d rather wait until all of the sprouts are ready, you can cut the entire stalk in one go. Use a sharp knife to slice through the thick stalk. Then, you can remove the sprouts.
While most will toss out the stock, it’s edible, too. Stalks have a lot of nutrition and flavor. They do take longer to cook and soften. But, you can season them up just the same.