By Sarah Giles
Searching for the best companion plants for broccoli to improve your crops? The good news is there are plenty of herb, flower and vegetable planting combinations you can try to increase the flavor of your broccoli and to deter harmful pests.
Companion planting used to be based purely on garden folklore, and the experience handed down from one generation of gardeners to the next. But there’s now an increasing body of scientific evidence to suggest that it really does work.
So what exactly is companion planting? Essentially, it’s a way of recreating the kind of balance that occurs in nature – when plants mingle together rather than being segregated into rows of single species. In the veg patch or on the allotment, that means planting edible crops alongside others that will help them to thrive rather than devoting each bed solely to one crop.
Companion planting for broccoli works in a number of different ways, depending on which crops you’re putting together. Some of the best companion plants for broccoli are good at repelling insects, while others bring in pollinating insects, thereby benefiting both themselves and their neighbors. Crops can take up valuable nutrients from the soil as they grow, but there are a select few that add them back into the soil, helping to keep companion plants healthy and productive. There are others that can even help to promote faster growth and better flavor in neighboring crops. Some make good companion plants because they provide ground cover, growing low across the ground and keeping moisture locked in – or their leaves may act as shade sails, keeping the hot sun from their more delicate companions in high summer.
Fast-growing plants can act as an aide–memoire if they’re planted alongside slower growing companions too, indicating exactly where your sowing rows are until the later crop has had a chance to germinate.
Why should you use companion plants for broccoli?
Broccoli – which is an umbrella name that includes calabrese and purple-sprouting varieties – is considered to be a ‘superfood’, thanks to the fact that it's packed with health-giving vitamins and minerals. It’s even said to have anti-cancer properties, so it’s definitely worth learning how to grow calabrese at home. But it can be difficult to keep it healthy and productive if it doesn't have the right conditions – and putting the right companion plants for broccoli alongside it can go a long way to helping with that.
One of the biggest problems is that broccoli has to stay in the ground a long time before it’s ready to harvest, and consequently it takes up a lot of space in your kitchen garden ideas – good reasons for trying companion planting for broccoli to make the most of every inch of space.
Best herb companion plants for broccoli
If you've been thinking about how to create a herb garden alongside your veg crops, make sure you consider these herb planting partners for your broccoli.
Because it has a strong smell, thanks to the aromatic oils in its needles, rosemary is good at repelling insects that would otherwise lay eggs in the broccoli crowns. The resulting caterpillars can devastate a crop overnight, so it makes perfect sense to grow a few rosemary plants in among your broccoli.
Although a rosemary bush can get quite big, if you pick it regularly to use in cooking it’s easy to keep the plants at a manageable size. Alternatively, pick a few sprigs of rosemary from elsewhere in the garden and simply strew them quite thickly around the base of your broccoli plants (they’ll keep slugs and snails away too).
There's plenty of tips on how to grow rosemary in our guide.
A common sight in Mediterranean gardens, this herb is thought to release a chemical that helps broccoli (as well as other plants in the brassica family) to not only grow faster but also to taste sweeter.
It’s recently been discovered that there’s a compound in broccoli that only some people can taste, and to those unlucky few broccoli seems very bitter – so anything that can make this super-healthy vegetable more palatable to everyone has got to be a good thing.
Summer savoury, which tastes similar to thyme, also seems to have a beneficial effect on the flavor of broccoli.
Best flower companion plants for broccoli
It's not just herbs that work well as companion plants for broccoli. These pretty blooms can also have similarly beneficial effects.
In the same way as marjoram and summer savory, this pretty plant is also thought to release a chemical that can speed up growth and improve the flavor of broccoli. Not only that, but its pretty white and yellow flowers attract pollinating insects too.
At the same time, broccoli does chamomile a favor by shady it with its large leaves – as chamomile prefers partial shade to full sun, it’s a win-win situation for both parties.
Our top tip is to sow chamomile seeds about 7.5in (20cm) apart from your broccoli plants, to give both enough space to grow.
Nasturtiums will happily scramble among a row of broccoli plants and there are two good reasons for including them as a companion plant in your raised garden beds. The first is that their strong, peppery scent will repel many insects. And the second is that those insects that are not put off by the scent and do lay eggs are likely to prefer the underside of the nasturtium leaves rather than the broccoli foliage.
Although the nasturtiums will ultimately be sacrificed for the good of the broccoli, you’ll still have the benefit of the pretty (and edible flowers) for some time before the foliage is shredded by caterpillars and the nasturtiums need to be removed.
Best vegetable companion plants for broccoli
Add these vegetables to your potager garden and you'll be rewarded with a healthier broccoli crop come harvest time.
Broccoli tends to take a lot of calcium from the soil, and that means that there are some crops it will fight with to get enough – with the end result that neither of them can thrive. But beetroot needs much less calcium than broccoli, so the two make a perfect pair in the veg patch or on the allotment.
For best results with how to grow beetroot alongside broccoli, just be sure to leave about 20in (50cm) growing space between them and they will happily co-exist, giving you good, healthy harvests of both crops.
If you're learning how to grow potatoes, there are lots of plants that can’t be grown alongside them (like tomatoes, peppers, carrots, cucumbers and onions) as they’re a really greedy crop and steal too much magnesium and phosphate from the soil. But, happily, broccoli requires different nutrients so the two make excellent bedfellows and are frequently grown together with good results.
Simply put young broccoli plants in the gaps between the rows of mounded earth where the potatoes are growing.
You'll find more companion plants for potatoes in our dedicated guide.
Lettuce is an excellent choice for the best companion plants for broccoli for a couple of reasons. First, rows of broccoli interplanted with lettuce look fantastic, especially if the lettuce varieties are in a range of different colors (from the lime green of frilly ‘Lollo bionda’ to the mottled red of ‘Merveille de quatre saisons’).
But the two are not just frequently grown together for aesthetic reasons. Lettuce suffers badly in hot weather and will wilt and quickly run to seed in a good summer. The shade from the broccoli foliage, though, keeps lettuce cool, and helps it to stay productive so that it will go on for much longer, potentially giving you cut-and-come again pickings at least three times from each lettuce plant.
What not to plant with broccoli
Just as there are plenty of good companion plants for broccoli, there are also some things that won't do well when planted near to this brassica. Make sure you avoid the following combinations if you want the best from your crops.
- Tomatoes Just like broccoli, tomatoes (as well as aubergines and peppers) need a lot of calcium, so the two don’t make happy neighbors in the veg patch. Better to keep them well apart if you're learning how to grow tomatoes and choose alternative companions for both, otherwise you’re likely to find that one or both crops quickly become calcium deficient (you’ll first notice yellow or brown spots on the leaves, which then develop a well-defined brown edge).
- Cabbage The trouble with growing cabbage alongside broccoli is that they are both in the brassica family, and putting one or more brassicas together is like issuing an open invitation to harmful insects, such as aphids, to come and enjoy a feast in your veg bed. A second problem with combining brassicas is that both will compete for the same nutrients – something that companion planting sets out to avoid at all costs as neither crop can thrive when that happens. For the same reason, avoid planting cauliflower and broccoli together. There are plenty of tips on how to grow winter brassicas in our guide.
- Strawberries If you're learning how to grow strawberries, avoid at all costs combining them with any member of the brassica family! They are sworn enemies in the veg bed because, for reasons that are not yet fully understood, they seem to significantly hamper the growth of the brassicas. So be sure to keep strawberries well away from not only broccoli, but also cauliflower, kale, Brussels sprouts and kohl rabi.
Sarah is a freelance journalist and is lucky to be able to write about her two main passions: gardening and food. Ten years ago she moved from a house with a tiny town garden to a much bigger space in the country and since then she's slowly been putting into practice all the garden design ideas she's been mulling over for years. Trouble is, as soon as she's got the garden looking how she thinks she wants it, she decides to start on a new project so it's a constant 'work in progress'. She took on an allotment last year too, and is really loving growing all her own fruit and veg then bringing it home to try out in new recipes for her food and gardening blog, A Cook's Plot.
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