All plants growing in the wild, grow in companion to other plants, so it’s ok to do this in your garden. However, there are some plants that do better with others, and some that will be problematic. Companion planting brassicas will give your brassica plants the best companions, and show you what not to grow with brassicas.
What Are Brassicas?
In easy terms, brassicas are all members of the cabbage family, and so members include:-
- Cabbage
- Cauliflowers
- Broccoli
- Calabrese
- Kale
- Brussel Sprouts
- Collard Greens
There are also some members of the brassica family that might surprise you, like
- Turnips
- Kohlrabi
- Radishes
- Swede(Rutabaga)
For a more indepth look at what are brassicas follow the link below the following quote.
brassica is a genus of plants in the mustard family
wikipedia
Companion Planting Brassicas
What are good companion plants for brassicas? Well, all of the following make great companions for members of the brassica family.
Onions As Companions For Brassicas
Onions are in the soil for a long period of time, and so they will not disturb the brassica roots when harvested. They also give off a strong aroma which will deter whiteflies, aphids, and cabbage white caterpillars from attacking your brassicas.
Leeks Make Great Brassica Companion Plants
Another member of the allium family, leeks will also keep pests away because of their aroma, and are in the ground for a long period of time.
Chives As Companion plants For Brassicas
This herb is also a member of the allium family, and works in the same way as it’s relatives. They also have extremely attractive purple/blue flowers that attract many pollinators to the garden.
Garlic Is A Great Brassica Companion Plant
As it spends at least half a year in the ground, garlic is another useful allium to grow with brassicas. It will help to keep the pests away, and a garlic spray can be made that will be even more effective. For more on companion planting garlic and how to make a garlic spray, click this link.
Peas As Brassica Companion Plants
As with all legumes peas fix nitrogen in the air and this leaves the nitrogen in the soil for the hungry brassica crops. Peas also grow upwards utilising less space for 2 crops.
Beans Are Great Companions For Brassicas
Another legume crop, beans are ideal companions for brassicas. Grow taller varieties to save on space, or bush types if you have room. keep legumes away from alliums as the sulphur in the alliums will prevent the nitrogen fixing that legumes rely on.
Companion Planting Brassicas-Herbs
I already mentioned chives, but there are many other herbs that when companion planting brassicas with are beneficial. These include,
Thyme As A Good Companion For Brassicas
This low growing, aromatic herb will help keep pests away by disguising the smell of brassicas. Once thyme flowers, the heavy traffic of pollinators will also deter many pests.
Rosemary And Brassica Companion Planting
A wonderfully strong smelling herb, rosemary will help to keep the pests away from your brassicas. With the added bonus that you don’t have to grow the rosemary near to your brassicas if you don’t want to. Just cut some sprigs and lay these around your brassica plants.
Mint To Deter Pests From Brassicas
I nearly excluded mint from this list, because it can be so invasive. Due to it’s strong aroma mint will keep many pests away from your brassicas but it’s best grown in pots. Even in pots watch out for the roots, which can grow through the pot and keep growing.
Sage And Brassica Companion Planting
Another strong smelling herb, sage will deter many pests from your brassicas. Also good for deterring flea beetles, sage shouldn’t be grown near onions or other alliums.
Dill And Companion Planting Brassicas
This tall growing herb once in bloom, will attract many helpful pollinators and wasps to your plot. Including parasitic wasps that will keep pest numbers down.
Chamomile The Health Giving Herb
Growing chamomile as a companion plant will improve the flavour of your brassicas and alliums too. It attracts many helpful insects like hoverflies and wasps including parasitic wasps, great for keeping pest numbers down.
Basil And Brassica Companion Plants
Strongly aromatic, basil makes a great companion for brassicas. Basil helps to disguise the brassicas from pests.
Companion Planting Brassicas-Flowers
Some flowers make great brassica companions, below are the best of the bunch.
Marigolds As Brassica Companion Plants
Every gardener should have marigolds growing, they are such a helpful plant. Marigolds deter nematodes which can damage plant roots, killing the plant. They also attract many useful insects.
Marigolds also repel whiteflies, but on the downside they attract slugs, so growing them as a trap crop can also be useful. For more on marigold companion planting follow this link.
Geraniums And Brassicas
The pretty geranium flower comes in many colours, and as they are all strong smelling, they will all work against the cabbage white butterfly. Grow geraniums as companion plants with brassicas, and benefit from a colourful display and less caterpillar damage. For more information on companion planting geraniums click here.
Nasturtiums And Companion Planting Brassicas
This easy to grow, versatile, edible plant, acts as a deterrent to some pests but attracts others. You can grow nasturtiums as a trap crop for black fly(aphids) just squash the little pests between your thumb and forefinger. All brassicas need plenty of calcium, and nasturtiums will grow in any soil type, however nutrient poor.
To find out more about companion planting nasturtiums click here.
What Not To Grow With Brassicas
As with all things there are good and bad neighbours and some plants should never mix.
Dahlias And Brassicas
There is strong scientific evidence that the same fungal infection (verticillium longisporum) that is often prevalent in dahlias can pass onto brassica crops. For this reason they should be kept apart in growing situations.
Peppers And Brassicas
The same fungal infection that affects dahlias also affects peppers, so it’s best not to allow brassicas to grow in the same area to avoid infection.
Potatoes And Brassicas
As potatoes spend a long time in the soil, the temptation is there to companion plant with brassicas. The problem is they are both heavy feeders, and so one will deprive the other of nutrients. Eventually neither crop will prevail. Brassicas need plenty of calcium and if potatoes get too much calcium they develop scab.
Tomatoes And Brassicas
Potatoes and tomatoes are members of the same family, and for the exact same reasons they will not do well with brassicas. In the main with this combination it’s the tomatoes that will lose out.
Strawberries And Brassicas
Brassica crops will not grow well if planted too close to strawberries. This is because strawberries exude a chemical through their roots that inhibit brassica growth.
Sweetcorn And Brassicas
Due to the heavy feeding habit of sweetcorn, it makes a bad companion for brassicas. Brassicas themselves need nutrient rich soil, and they will not both survive as companions.
Squash And Brassicas
All squashes are heavy feeders and as such should not be grown anywhere near brassicas.
I hope you find companion planting brassicas a useful tool in your growing program. Please let me know in the comments below.