July 11, 2025, 5:30 am | Read time: 3 minutes
Cucumbers are a popular vegetable among hobby gardeners and self-sustainers. When planting this vegetable, it’s important to pay attention not only to the cucumber itself but also to the plants on either side. Some neighboring plants can negatively affect the growth of cucumbers.
Companion plants like marigold, tagetes, or garlic are ideal for promoting the growth of cucumbers. On the other hand, there are also plants that should not be planted in close proximity to them. myHOMEBOOK introduces vegetables and herbs that would be poor companions for cucumbers.
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Poor Companion Plants for Cucumbers
1. Tomatoes
Alongside cucumbers, tomatoes are particularly popular among hobby gardeners. It almost seems obvious to plant the two vegetables next to each other, as they have similar site requirements. However, this should be avoided. Tomatoes are unsuitable companions for cucumbers.
Due to their similar demands for light, soil, and nutrients, the plants compete for essential resources. The plant that grows faster, receives more light, is stronger, and absorbs more nutrients will overshadow the other. The result: At least one of the two vegetables will grow poorly and produce meager or no fruits at all.
Also interesting: 3 Tips to Accelerate Cucumber Growth
2. Pumpkins, Melons, and Zucchini
It sounds curious, but alongside pumpkins, melons, zucchini, and cucumbers are also part of the gourd family. While in some cases, a relationship among plants can be beneficial, the different members should not be planted next to each other in the garden bed.
All four plants have a high demand for nutrients and space. They would compete with each other, minimizing the harvest. Additionally, they are more susceptible to similar diseases, such as powdery mildew. If they are close together, the risk of them infecting each other is higher.
3. Radishes and Radish
Apart from the fact that radishes and radish have different site requirements than cucumbers, there is another reason why they are poor companions. Radishes and radish belong to the cruciferous family. They can leave substances in the soil that inhibit the growth of other plants or lead to soil fatigue.
4. Sage
Sage can also cause problems in the garden bed–making it a poor companion for cucumbers. The herb contains essential oils. While these make sage a valuable medicinal plant, they can cause trouble in the garden soil. The essential oils can inhibit the growth of neighboring plants.
Also interesting: 5 Common Causes of Yellow Leaves in Cucumbers
5. Lovage
Lovage, also known as Maggi herb, is a deep-rooting and vigorous plant. As a result, lovage displaces other plants from the garden bed. Additionally, Maggi herb can have a growth-inhibiting effect on neighboring plants. The reason for this is so-called root exudates, which are substances secreted by the roots.
Ideal Companion Plants for Cucumbers
“Cucumbers thrive best next to plants that have similar site requirements but do not pose competition. It is also important that the plants do not share common diseases and pests. Good companion plants for cucumbers would be dill, spinach, and marigolds.”