I’ve been growing Brussel sprouts in my backyard for a few years now and have managed to get a bumper crop this winter. In fact, the plants yielded more sprouts than before and were the tallest they had ever grown and … they were 3 foot tall!
Brussel sprout plants can grow to be as tall as 2 to 3 feet in height when supported by canes. This means you could expect to grow a plant of Brussel sprouts up to 90 cm tall. That’s very high for a sprout plant but it is possible.
Knowing the plant’s height can help you prepare the best space in your garden to grow your own backyard Brussel sprouts. But if you do want to get your sprout plants to grow as tall and as mine do, sometimes yielding more than fifty sprouts per plant, read my tips further down the page.
How tall and wide do Brussel sprouts grow?
A healthy Brussel sprout plant can be as wide as 1 foot (30 cm) and as tall as 3 feet (90 cm). Due to the relatively large space, they take up, those planting them in backyard vegetable patches, need to anticipate the space needed.
Tips for growing tall Brussel sprout plants in your backyard
1. Space them out as seeds and when re-planted as seedlings
For your Brussel sprouts to grow as tall as they possibly can, you need to space them out when planting them in March time. If you don’t space them out properly, they can stunt in growth and won’t get as tall.
I recommend that Brussel sprout seeds are planted 1.5 cm (0.5 inches) deep and 8 cm (3 inches) apart from each other. But stop there… once those seeds grow into seedlings you will be re-planting them outdoors, and wider apart.
If I am planting Brussel sprout seeds in March time (which will mean they are ready for Christmas), by May, the seedlings should be about 15 cm tall (6 inches). At this height and date, they can be taken outside to be re-planted in your backyard or garden.
In the outdoor planters, Brussel sprout seedling will need to be placed 45 cm (18 inches) to 60 cm (24 inches) apart. By having this space between them, Brussel sprouts can grow tall and wide, giving you a bumper harvest in the winter months.
Handy Hint: Sprouts are biennial plants and will not grow back again with a yield the following year.
2. Use supportive canes to get taller plants
To help Brussel sprout plants grow taller and wider, I will use supportive canes (view on Amazon). Because the plants have the potential to grow to 3 feet tall, buy canes tall enough like the ones in the photo below (click the image for prices).
It’s important to use stakes like this if you want your Brussel sprouts to grow tall and wide, because once the sprouts grow on the stalks, they can start to topple over. If the topple, they can be at risk of mold or critters getting to them.
Add the supportive canes when you plant the sprout seedlings and continue to monitor from May through until December.
3. Don’t pick the sprouts too early
Also, please note that longer Brussel sprouts are in the ground, taller they grow. As a rule of thumb, sprouts have a long growing season of between 80 and 100 days.
4. Keep watered, but not too watered
Brussel sprouts need water, but not as much as you might think. If you plant them outdoors in May through to December, they will endure a possible hot summer then the start of winter.
You might not have to water the Brussel sprouts to make them grow tall if you live in a mild climate with regular rainfall. However, if your plants are in dry weather, make sure you water them every couple of weeks.
5. Protect the sprout plants from insects and birds
Critters love to get at backyard Brussel sprouts. Your plants will never grow tall if they are constantly being pecked at.
I use protective netting kit which you can get on Amazon. It means I can help protect the Brussel sprouts which can then grow as tall as 3 feet high.
6. Make sure the soil is fertile and not protected from wind
Brussel sprout plants will not grow tall in poor soil, it needs to be very fertile for them to thrive. I recommend using a fertilizer with half and half organic matter.
In summer I add nitrogen-rich fertiliser. The best I have used is dried poultry manure pellets.
The plants should be out in the open but have protection from the wind. If wind batters the plants, they won’t grow tall and could even break – have them near a windbreak and use the canes I recommended earlier for added security.
And that’s it at a very basic level. Follow those tips, and I hope your Brussel sprouts grow tall and healthy like the ones in my backyard do.
The world record for the tallest ever Brussel sprout plant
You might think that my sprout plants are tall, but they are nothing compared to the world record holder. According to the official Guinness World Records website, one has been grown as high and tall as 3.35 metres!
“The tallest Brussel sprout plant is 3.35 metres (10 ft 11.8 in) and was grown by Dickerson Philip (USA) in Hawthorne, California, USA, on 18 July 2022. Phillip decided to embark on what he called “adventure” when he and his family realized that one of their “normal” Brussel sprout plants began to far outgrow the others.”
I have more tips on sprouts, with the links below including some more advice.
FAQs on growing tall Brussel sprout plants
Can you grow Brussel sprouts in pots?
You can grow Brussel sprouts in pots, but they need to be big pots if you want the plants to grow wide and tall.
I recommend a pot that’s about 7 gallons, a foot deep, and at least a foot wide. This will give you enough space to grow one Brussel sprout plant but appreciate it might grow as tall as it would in an outdoor soil environment.
Do Brussel sprouts need a trellis to grow tall?
You can use a trellis to help Brussel sprouts grow, but it’s not essential. As discussed, I get tall plants by using stakes or canes, which I then twine against the stalks to stop them flopping over.
How much space do Brussel sprouts need?
To grow tall Brussel sprout plants, you need the space I outlined earlier. This was 45 cm (18 inches) to 60 cm (24 inches) apart as seedlings.
Whilst it’s unlikely you will grow a Brussel sprout to be as tall as the Guinness Book of Records champion, there’s no reason why you can’t get as tall and as wide as my sprout plants.
If you take time, care, and attention, you will get a very tall plant I promise!
More backyard guides…
- When to plant Brussel sprouts in time for a Christmas harvest
- The strange tastes associated to sprouts
- What it means when mushrooms grow in your yard
Image used in header from https://en.wikipedia.org/wiki/Brussels_sprout#/media/File:Brussels_Sprouts_ready_for_harvest.jpg