One thing I love about gardening is the planning, with seed catalogs, soil test results, graph paper, and maybe a cup of coffee at the ready.
I find it especially gratifying to map out companion planting ahead of time. It’s like a game, deciding which plants will go where based on their potential to coexist or maybe even enhance each other’s growth.
It doesn’t make a huge difference for some vegetables or flowers, like okra, which grows well next to almost any other plant. But picking appropriate companion plants for mustard greens, one of my favorite veggies, really pays off.
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Certain flowers, herbs, and fellow vegetables help this fast-growing leafy green to be more vigorous, or to avoid certain pests and diseases.
And while there isn’t a lot of hard and fast science to back it up, generations of home gardeners swear by planting certain herbs next to mustard to enhance the taste as well.
I probably like this piece of the process so much because I can’t duplicate it in my everyday life. I mean, it’s rare for us to get to choose only neighbors who will bring out the best in us.
Nor can we easily move everyone to a more advantageous locale if it later becomes clear they’re not getting along.
Companion planting principles also allow another freedom we don’t often experience as adult human beings: It lets you ban the negative influences.
Mustard does have a few foes, in the form of plants that compete for space or nutrition, have conflicting soil and water needs, or create some other issue.
With a bit of planning, you can make sure to keep the bad neighbors away from each other.
How do you weed out the good choices from the rest?
First, understand that all mustard varieties are part of the Brassica genus within the Brassicaceae family, which means they’ll have a lot of the same friends and enemies as other cruciferous garden vegetables.
But because some members of this family fall into different species and even genera, including Brassica juncea, B. rapa, B. nigra, B. hirta, and Sinapis alba (formerly B. alba), there will be a little bit of deviation among the different types.
Tatsoi, for example, doesn’t grow as high as, say, ‘Southern Curled Giant,’ so you won’t have to worry as much about it blocking the sun from anything you plant nearby.
Still, mustard green varieties tend to have more in common when it comes to companion plants, and I’ll focus mostly on companions that will work for any of them.
Here’s what I’ll cover:
9 of the Best Companion Plants for Mustard Greens
Just like human friends, you’ll want to look for a variety of companions for mustard greens, because different plants can provide unique benefits.
Some deter pests, some are believed to improve flavor, and others just look great with the leaves of this spicy vegetable, offering ornamental value.
A few are merely neutral in their impact on mizuna, tatsoi, ‘Florida Broadleaf,’ and the rest. In some cases, the mustards confer all the benefits when they’re interplanted, with no reciprocation.
Here are nine of the top companion plants to grow with your mustard greens:
There’s no hard and fast research available that I know of to support this claim, but generations of home gardeners swear that celery (Apium graveolens) improves the flavor of many members of the cabbage family, including the various mustards.
And it’s definitely a good candidate to maximize space in small gardens. You can interplant it with your mizuna, tatsoi, or Southern-style curly varieties in early spring.
The celery can take months to produce, while the leafy vegetables mature in 20 to 60 days, with baby leaves and salad greens available early in the cycle.
‘Tall Utah’ grows 12-inch stalks, takes 120 days to reach maturity, and thrives in full sun. Find seeds in packets and bulk, available from Eden Brothers.
You can grow an entire crop of the leafy brassicas while the celery is just getting established.
They’ll be gone before the celery reaches full size, so you’ll get two harvests from the same spot while only preparing the bed a single time.
Tiny, daisy-like chamomile flowers can give a false impression. This herb is not at all dainty as a companion. It repels a range of brassica pests, like whiteflies.
There are two types of chamomile, German (Matricaria chamomilla) and Roman (Chamaemelum nobile), also known as English.
Both types attract a range of beneficial insects such as hoverflies and ladybugs and are resistant to insect pests, except for aphids.
You’ll do better employing the German variety as a companion for mustard greens, however, because it grows taller – two or three feet at maturity – compared to the Roman type that tops out at four inches.
German chamomile leaves are lacy and the blooms are small, so they won’t block the sun from the greens growing lower in the garden.
Roman chamomile spreads enthusiastically through rhizomes, though, and can choke out neighboring cole crops.
It’s better to use the spreading type of chamomile as ground cover, or to grow between pavers.
Those aren’t places you’re likely to plant ‘Red Giant,’ mizuna, ‘Tendergreen’ or any of these other leafy greens that will benefit from an association with chamomile.
But if you place a container of greens near a patch of Roman chamomile, that could work!
You can find German chamomile seeds available at True Leaf Market.
According to South Carolina-based master gardener Debbie Menchek, making a tea from the leaves is another way chamomile can benefit your crop of mustard greens.
Chamomile foliage is high in sulfur, so spraying a tea made from the herb’s leaves on young brassica plants may help to prevent disease. It kills fungal spores on both the greens and the soil where they’re growing.
Note, though, that once a fungus gets established on your seedlings, chamomile tea spray won’t help. It’s a preventive measure, not a cure.
Corn (Zea mays) grows up, mustard grows out, and they both appreciate soil with a neutral pH, so they make good neighbors. The fast-growing leafy vegetable defends the territory below the corn from weeds, too.
And by the time the corn is ready to start producing cobs, the greens have already been harvested, so there’s no competition for water or nutrients.
You can find ‘Bodacious’ seeds available at Eden Brothers.
Did you know dill (Anethum graveolens) is good to grow with mustard? Even if you’re no fan of pickles, that probably doesn’t seem surprising.
But it’s not really a question of the way the two plants taste.
It’s also convenient that dill grows well in cool weather. You can sow a first round from seed two or three weeks before your last spring frost, just three or four weeks after you get your first round of mustard growing.
Then you can successively plant more dill every three weeks all through the summer, so it will keep going even when its brassica friend has to take a break in the hottest weather.
The two can pick up their perfect pairing again for late summer and fall, all the way until it’s time to use the dill seeds in pickling, and to blanch the greens for freezing.
You can find heirloom ‘Bouquet’ seeds in a variety of package sizes available at True Leaf Market.
Garlic (Allium sativum) is a popular addition to stir fries, stews, and sautees that also include spicy tatsoi, mizuna, or other leafy greens.
But the pungent allium is also a great pairing with these plants while they’re still growing in the garden.
First, many herbalists and home gardeners plant garlic next to brassicas because they say it improves the flavor of the cole crops. Can’t hurt to try it, right?
And even if your taste buds don’t detect enhanced flavor, you’ll get the benefit of garlic deterring aphids, a sworn enemy to brassicas.
It may even keep rabbits from eating your produce, since bunnies are known to dislike the sulfuric smell of garlic. On the other hand, rabbits who are really hungry might just skip over the garlic and head for your greens instead!
You can find bulbs available from Burpee.
Mint (Mentha spp.) is a powerhouse natural insect repellent, and many of the bugs it deters have their sights set on eating leafy cole crops.
Mint can spread like crazy, so make sure you keep it contained. Or, plant it a little after your leafy greens. That way, you can harvest the fast-growing brassica before the mint takes over.
Find peppermint seeds available from True Leaf Market in packets and bulk.
I prefer growing mint in containers personally, so I can plant another veggie once the mustard has run its course.
I don’t like to yield valuable garden space to the free-roaming aromatic herb when I could plant three successive crops instead.
Check out our guide to growing mint to learn more.
Onions (Allium cepa) can help to repel pests that are common to mustard greens and other brassicas. They resist cabbage worms and cabbage loopers, for example.
Like corn, garlic, and celery, onions are a beneficial companion and also produce a substantial harvest of their own.
Day-neutral ‘Candy’ onion plants in two-bunch sets (for 150 plants total) are available from Burpee.
To maximize the bounty, along with planting a few rows in a neighboring patch of soil, try tucking a few onions anywhere they can get enough sun within a bed of cole crop plants.
Just make sure to give the alliums plenty of space. Onions won’t do well if they lose the competition for full sun, ample water, or proper nutrients.
You can learn more about how to grow onions in our guide.
8. Rosemary, Sage, and Thyme
Along with possibly inspiring you to hum Simon and Garfunkel tunes while you hoe and weed, rosemary (Salvia rosmarinus), sage (S. officinalis), and thyme (Thymus vulgaris) all have beneficial aromas that serve to qualify them as excellent companions.
All three are deterrents to the cabbage moths that look so graceful flitting about but are actually laying eggs that will hatch into larvae that eat holes in your precious greens.
Sage is also known to repel slugs.
And even if you don’t plant it near the mustard or other brassicas, you can use thyme to help keep your leafy vegetables healthy.
Steep a handful of thyme branches in a cup of boiling water for an hour or so, let it cool, and then use the room temperature “tea” to spray on leaves that are susceptible to whitefly infestation.
Check out our guide to growing rosemary to learn more.
Find broad leaf sage seeds, including an organic option, available at True Leaf Market.
Our guide to growing sage will help you get started.
Thyme seeds are available in a variety of packet sizes from Eden Brothers.
Learn more about thyme in our growing guide.
The one drawback to interplanting these three herbs with your mustard is that it is an annual crop while they are perennials. That could cause problems when you need to mulch and till to plant again next season.
I recommend planting these beneficial brassica companions at the corners of your gardens to prevent a lot of hassle.
Or, consider growing at least some of them in containers, so you can move them out of the way to till the soil or amend it.
Besides looking pretty and lacy next to your cole crop, yarrow (Achillea millefolium) attracts many insects that help to keep aphid populations in check, including hoverflies, ladybugs, and lacewings.
In addition, if you’re like me and frequently let greens or other cole crops flower, the hues of the yarrow blossoms look great next to those bright yellow blooms.
Colorado Mix features yarrow with pink, red, yellow, and white flowers.
Find Colorado Mix seeds in packets or bulk at Eden Brothers.
Bad Plant Neighbors for Mustard
Along with picking good neighbors for your mustard greens, you can also increase their growth and yield by keeping them away from the plants that cause issues.
Here are three you shouldn’t plant nearby:
There is a lot of conflicting advice about bush beans and members of the cabbage family, so if you’ve always had success planting these two near each other, don’t worry about it.
However, some home gardeners don’t like bean plants’ tendency to fall prey to mold and mildew, and then pass those infections to brassicas planted close by.
For example, the same Sclerotinia sclerotiorum fungi that causes white mold in beans via the flowers, stems, and pods can spread to brassicas like mustard plants via the soil, which might make you consider planting this cole crop at a few steps removed from your beans.
And pole beans add another negative possibility. They grow tall enough to block sunlight, which presents a problem for the varieties that require full sun and can’t handle even partial shade.
Of course, mustard greens tend to be done for the season by the time pole beans are that large, so if your choice is to grow them next to pole beans or skip them, I say go for it.
Nothing against the plants in this wonderful family, but nightshades are prone to verticillium wilt..
Once infected, if they’re close to your cole crops, they’ll pass the wilt along.
Though verticillium wilt can take much longer to devastate nightshades, it can destroy your whole mustard harvest in a short while.
Some potatoes are less likely to succumb to this wilt than others, but if you’re not sure you’re growing one of them, it’s a good idea to keep the spuds and brassicas separated, too.
While you’re at it, see if you can’t wait an extra season before planting brassicas in beds that nightshades of any sort, even tomatillos, occupied the year before. Verticillium wilt is soilborne and can take a few years to die off.
The exception here is sweet potatoes (Ipomoea batatas) because they are part of the morning glory family, not nightshade.
If you’re not worried about the wilt, it’s worth mentioning that nightshades and brassicas have a conflict with their desired soil pH, which is another reason they’re not good neighbors.
Mustard greens thrive in neutral soil with a pH of 6.5 to 7.0, and nightshades prefer a pH from 5.5 to 6.5. If you plant them in the same garden, one of the vegetables will not grow as well as it would in its preferred pH.
They’re both springtime delights, yet strawberries and mustards – all brassicas, in fact – make bad bedfellows. The shortcake fruit plants draw slugs, which then move over to eat those healthy greens.
Strawberries also compete for nutrients, which is something leafy greens need in ample amounts.
And if you’re not super-attentive to the berry plants, they’ll form a thick mat of runners that can choke out the mustard greens, or deprive the small ones of water or sunlight.
It isn’t such a big deal in the fall, when strawberries tend to be dormant. But for that early spring crop of luscious tatsoi or ‘Florida Broadleaf,’ keep these two varieties of plants far from each other or in different containers.
Mustard Greens Matchmaker
One last thing to keep in mind when you’re choosing those companions for your precious mustard greens: You may need to adjust as you go along.
There are no guarantees your plants will grow well with the flowers and vegetables suggested here, or even that they will suffer if planted next to some of the bad neighbors I’ve described.
I would never plant two known foes next to each other if I had another option, but for the beneficial pairings,I agree with a bulletin from Cornell University’s Cooperative Extension Chemung County.
The authors advise gardeners to take all companion plant recommendations as “a starting point for individual trials….Continue doing what works and abandon what does not.”
What’s swell about mustard greens is that they’re fast-growing and relatively inexpensive to sow from seed. So if you find they’re not working somewhere, it’s cost-effective and low-labor to pull that batch and start a new one next to better garden neighbors.
Which brings us back to you. Have you found any particularly beneficial companions for this spicy brassica? Or any veggies, flowers, or herbs you’d never plant next to mustard again?
It’d be great if you would share your experience in the comments section below!
And for more information about mustard greens, check out these guides next:
About Rose Kennedy
An avid raised bed vegetable gardener and former “Dirt to Fork” columnist for an alt-weekly newspaper in Knoxville, Tennessee, Rose Kennedy is dedicated to sharing tips that increase yields and minimize work. But she’s also open to garden magic, like the red-veined sorrel that took up residence in several square yards of what used to be her back lawn. She champions all pollinators, even carpenter bees. Her other enthusiasms include newbie gardeners, open-pollinated sunflowers, 15-foot-tall Italian climbing tomatoes, and the arbor her husband repurposed from a bread vendor’s display arch. More importantly, Rose loves a garden’s ability to make a well-kept manicure virtually impossible and revive the spirits, especially in tough times.