Scallions offer a great choice for companion planting in the garden and are my choice for filling in the gaps in my garden beds. You can get away with planting scallions anywhere, but there are some plants which do better with scallions than others.
Scallions are sometimes called green onions. They are technically different, as green onions can grow a small bulb if left to grow long enough while scallions remain straight all the way down, but this guide applies to both equally and both are amazing companion plants.
Scallions have shallow root systems and narrow leaves, so they grow best around plants that have deep root systems and in any open gaps between larger plants. You can plant scallions between beets, Swiss chard, carrots, radishes, lettuce, and cabbage. For larger plants like tomatoes, full-sized kale, pepper plants, you will need to plant them farther away, at least 12 inches. They can also be planted between herbs like dill, parsley, coriander/cilantro, thyme, and rosemary. Avoid planting them next to mint family herbs as mint always takes over whatever they are growing in and could outcompete your scallions for nutrients.
What Is Companion Planting?
Companion planting is the planting of more than one type of plant together in the same area, in a way that they both benefit more than they would if they were planted separately. A related term is intercropping, which just means planting vegetables or flowers between other plants. I’ve already gone into more detail on companion planting and intercropping, but there are a few basic points to consider.
There are several reasons to try companion planting in your garden:
- It maximizes efficient use of space in your garden by filling in “empty” spots in your beds.
- Interplanting flowers or flowering herbs and vegetables attract beneficial insects to your garden, such as pollinators and wasps that will eat pests.
- Companion planting unrelated vegetables can confuse pests, leading to less pest damage in your garden.
There is the notion that companion planting can improve the flavor of your vegetables, like planting basil next to tomatoes, but so far these claims have been unfounded. But keep planting that basil next to your tomatoes, because they grow really well next to each other.
Does Companion Planting Really Confuse Pests?
Interplanting different families of vegetables does indeed confuse pests, but not in the way we used to think.
It was previously thought that the scent of certain plants, like strong-smelling herbs, would confuse them by smell alone. It turns out that isn’t the case.
What research at the Horticulture Research International in the UK [PDF] has found is that pests like egg-laying flies and butterflies will repeatedly fly and land around a plant to lay eggs. If they keep landing on the same plant, they know it’s the right one and will start laying multiple eggs or taking nibbles out of your leaves. If they flutter about and keep landing on different plants in the same small area, they get confused and think they are not on the right plant, and will move on.
Why Scallions Are the Perfect Companion Plant
Scallions and green onions and their cousins (onions, chives, garlic, and leeks) make perfect companion plants and are my go-to choice for filling in gaps in my garden.
1. Scallions grow very quickly, often giving you your first harvest in less than two months.
This means you can plant them next to larger vegetables that take a longer time to mature. For example, kohlrabi and kale really spread out and can shade out scallions if planted too close, but you can get a scallion harvest before they mature and then replant farther away for a second harvest.
2. Scallions have shallow root systems and thin leaves.
Scallions will not take much space, both above ground or beneath the soil, so they won’t compete with deep-rooted vegetables or larger plants.
3. For confusing pests, scallions are in a separate family from most vegetables.
If you are companion planting to reduce pests naturally in your garden, scallions make an excellent choice. Scallions are part of the allium family, which includes a short list of vegetables: scallions, onions (green/bulb), chives, leeks, and garlic. A lot of the pests that attack alliums don’t go after other vegetables and vice versa. Tomatoes, eggplants, tomatillos, peppers, and potatoes are all in the nightshade family. The same for cucumbers, zucchinis, summer squash, winter squash, and melons, which are all in the cucurbit family. So by interplanting scallions in your winter squash patch, for example, you will not be attracting more pests and may even confuse some squash bugs or vine borers.
What Do Scallions Grow Well With?
Scallions grow well with most vegetables. Since they have shallow roots, they won’t compete with beets, Swiss chard, carrots, radishes, lettuce, or cabbage. Even larger plants like tomatoes and peppers can be interplanted with scallions, but I would plant them at least 12 inches away from the stem, and perhaps farther if you want to keep your scallions from being completely shaded. If you are growing cucurbits like winter squash along the ground, you can plant scallions around them and they will grow up and poke through the squash foliage.
Non-sprawling herbs like cilantro/coriander, dill, parsley, thyme, and rosemary can have scallions planted around them, but avoid planting scallions with herbs or other fruits or vegetables that spread out, like mint and strawberries.
Related Questions About Companion Planting Scallions
Can I Plant Scallions with Bulb Onions? Garlic?
You can definitely plant scallions with onions and garlic. Scallions have very shallow roots, so they won’t compete with onions or garlic. Scallions also quickly reach maturity, so you can often plant and harvest them before your onions start growing big bulbs. I like planting scallions in the gaps between my onions or around the outside of my garlic patch.
However, if you are companion planting to confuse pests, scallions won’t really be that beneficial as they are all in the same family. In fact, regular onions and scallions share a lot of the same pests.
Can I Plant Scallions with Tomatoes?
Scallions make excellent planting buddies with tomatoes. They share no major pests, and while tomatoes are space hogs, scallions can be planted in nooks and crannies around your tomato beds.
If you plant your scallions before your tomatoes, you can plant them really close to where your tomatoes will be, and have enough time to harvest them before the tomatoes shade them out.
For mature tomato plants, or plants that are quickly growing, you ideally want to plant scallions at least a foot or so away from the tomato plant, as tomato roots sytems can spread out a lot. As a rule of thumb, plant scallions at least at the edge of your tomato leaf canopy so the leaves won’t shade out the scallions. The best place to plant scallions next to tomatoes is along the north, east, or west side of your tomato row so they can get enough sun. Scallions planted on the south side of a tomato row might be shaded out too much.