Choosing the best companion plants for cucumbers largely involves repelling pests and improving growing conditions. Cucumbers are perfect for balcony gardening because they love pots and grow vertically. As such, it’s worth finding companion plants that also appreciate pot growing.
Let’s look at some of the most suitable cucumber companion plants specifically for balcony gardening.
Dill is one of the few herbs you can grow near cucumbers. Importantly, it attracts pollinators and predatory insects. You don’t need to plant it in the same soil as the cucumbers – nearby is fine.
Providing you have a suitably large planter (like this), corn makes a great cucumber companion plant. The stalks act as natural support for the trailing cucumber plant, meaning you don’t need to set up as many stakes. However, this only works for small cucumber varieties, as larger ones will be too heavy.
Marigolds are a gardener’s best friend. They help to repel pests, particularly aphids, which are a big threat to cucumber leaves. When using marigolds as cucumber companion plants, just keep them in a pot next to the cucumber. They don’t need to share the soil.
Radishes are a root crop, meaning they don’t use a lot of space above the soil. This makes them great companion plants for cucumbers, which have relatively shallow roots. A 5-gallon planter (like this) is fine for a single cucumber plant, and you can then sow a few radishes on top.
Along with using different parts of the soil, radishes repel cucumber beetles. Unsurprisingly, these feed on cucumbers.
Nasturtiums are a trap crop, meaning they attract pests away from your precious vegetables. If you plan to use nasturtiums as cucumber companion plants, make sure they’re a few feet away so the pests don’t move from one plant to another. A simple railing planter (like this) is perfect for growing nasturtiums.
Just as we have ideal cucumber companion plants, there are also things to avoid growing near them. The most applicable ones for balcony gardening include:
Melons, squash, and pumpkins are all cucurbits, as are cucumbers and zucchini. Avoid growing them with cucumbers because they’ll compete for space and nutrients, meaning you won’t get the best from any of them. Also, they’re vulnerable to the same pests and diseases.
Cucumbers have a tendency to take on the flavors of nearby crops during their growth cycle, mainly because they have such a high water content. As such, powerful aromatic herbs like sage and mint can taint the flavor.
Also, mint is a very aggressive – and almost invasive – plant. Growing it in the same soil as any plant may smother the less dominant crop.
Despite being unrelated crops, potatoes compete for many of the same nutrients as cucumbers. They also both need a lot of water, and potatoes are unsurprisingly dominant in the soil. Cucumbers can increase the chance of potato blight, too, so keep these crops away from each other.
Brassicas have the same issue because they also love water. Luckily, you can grow them in pots near your cucumber plants, just don’t keep them in the same soil.
Cucumber companion plants are fairly easy to work out: just avoid anything that is a heavy feeder or a water lover. Importantly, the trap crops like nasturtium and marigold benefit almost all the food crops you can grow on a balcony. So, chuck things in their own pots, and happy planting!