The One Plant You Should Never Grow Near Basil
If you're set on growing basil, perhaps so you can use it to make fresh pesto, there's one plant you don't want to try to grow alongside it. That's the cucumber. While both may be great additions to a salad, cucumbers will fight for most of the same resources in your soil that basil needs, and that often means one plant will do better than the other.
Another reason not to include basil plants near your cucumbers is a change in flavor. Cucumbers have a very mild, watery taste to them, but when grown too close to basil (or other strong, pungent herbs), the plant can pick up on some of that distinct basil flavor. Unless that's what you're after, it's best to keep these two plants away from each other in the garden or plant them in two different containers on the other side of your patio.
Basil isn't a finicky plant to grow, though. You can easily plant it with other herbs, root vegetables, and even flowers without complications. It's not always a good idea to mix it with thyme or fennel, however, since, like cucumbers, they also compete for the same resources. As you work to plan out your basil garden, there are a few tips that can help ensure it all works together well.
Basil and cucumber will compete for nutrients
Creating a cohesive garden means ensuring ample nutrients are available for all plants within it. Various plants need different levels of minerals like nitrogen. When you plant, you don't want to have too many nutrient-depleting plants within the same area, as such a setup will limit growth as the plants compete for resources. Even if you're adding in fertilizer and organic matter, it can be a battle to create an effective balance.
When it comes to basil, its demand for nutrients is typically high. It also prefers a balanced pH level. Cucumbers are similar to basil when it comes to nutrient demand, and the fruit plant also tends to benefit from well-drained soil. This similarity is a major reason why you should never grow cucumbers near basil. While the two compete for resources, you'll likely notice it takes longer for your basil plant to recover after you harvest it. Cucumbers may still come in, but there are likely to be fewer because of the scarcer resources.
What to grow with basil
While cucumber may be the one plant you don't want to grow with basil, it turns out the herb doesn't need a lot of companion plants to support its growth and development either. For this reason, you can grow basil in its own container of well-drained soil.
However, if you want to plant basil with other herbs in your garden, focus on options like oregano, chives, and chamomile. Or, consider growing fruits like tomatoes and peppers with it. These plants are excellent companion options for basil because they thrive in the same type of environment but are also hearty and less likely to pick up on any flavor changes from growing near basil.
You can also switch things up and plant flowers, especially marigolds, near your basil. They have a strong scent themselves that can create a pungent deterrent for some pests, like aphids, from the area. Basil mixed with any type of strong-scented flower can create a natural level of pest control for your space and even ward off deer and other herbivores looking for a tasty meal.