Don’t Plant These 11 Crops With Your Cucumbers

I love growing cucumbers. Not only are they healthy and tasty, but they are an easy crop to grow, and they tolerate the hot summers here in zone 9. Chopped up on a salad or slipped into a sandwich, the crisp, refreshing flavor is always welcome. And, if you’re a pickle person, there is nothing quite like homemade.

Cucumbers, like many crops, have specific needs, and those dictate which other plants they work well with. Companion planting is a great way to grow more than one vegetable or fruit, in a way that benefits both. Marigolds, for instance, make excellent neighbors for just about anything.

Some great neighbors for your cukes include beans and peas, carrots, and corn, among others. Just as there are good companions for these vegetables, there are also those that don’t make good neighbors. This is usually because they attract similar pests or compete for nutrients. 

Any time you set about planting a vegetable garden, it’s good to find out which vegetables work well together and which don’t. Let’s take a look at some of the plants that you should avoid growing near your cucumbers. 

Melon

	botanical name Cucumis melo
	sun requirements Full sun
	height Up to 20’
	hardiness zones 2-11

Melons and cucumbers are part of the same family, so they have similar needs. You might think that this would make them good companions, but it’s actually the opposite. Both of them have high nutrient demands, and both require a significant amount of nitrogen. Because of this, they compete for resources, which isn’t good. 

They’re also both susceptible to the same pests and diseases, so having them close to each other will draw extra pests. They both need space to spread out, so they not only compete for resources, but they also compete for real estate. Because of how closely they’re related, cross-pollination may be an issue if you intend to collect and use their seeds.

Pumpkin

	botanical name Cucurbita pepo
	sun requirements Full sun
	height 2’-30’
	hardiness zones 2-11

Pumpkins are also closely related to cukes, and so, for the same reasons, you should create some space between them. Their needs for similar nutrients will cause unhealthy competition, often leading to a reduced yield or subpar fruits. 

Squash bugs like both of these plants, and they are opportunistic, like most pests. If they see an opportunity to eat their fill and not have to go far, they will set up camp in that space. Pumpkins and cucumbers won’t cross-pollinate, but they make lousy neighbors regardless. 

Potato

	botanical name Solanum tuberosum
	sun requirements Full sun
	height 1’-2’
	hardiness zones 2-11

Plant your potatoes away from your cucumbers this year, or live to regret it. Potatoes are heavy feeders and will steal nutrients from other veggies. They will also compete for water, and cucumbers love hydration. 

Harvesting your potatoes causes root disturbance, so it’s truly best to give them their own space. They are prone to fungal diseases, as well, which can also have a negative impact. Keep these crops separated to keep them both healthier. 

Sage

	botanical name Salvia spp.
	sun requirements Full sun to partial shade
	height Up to 5’
	hardiness zones 2-11

There are herbs that work well in the vegetable garden, and others are better located elsewhere. Sage is one that isn’t compatible with cucumbers in particular, for a couple of reasons. First, sage likes dry soil, while cucumbers are moisture lovers, which makes it difficult to keep them healthy next to each other. 

Sage has a strong aroma and can release oils into the soil, which can affect the flavor of your cukes. It can lend them a bitter taste, and also affect the smell, making it less appealing. It can also hinder growth, making it a bad companion. 

Fennel

	botanical name Foeniculum vulgare
	sun requirements Full sun
	height 4’-6’
	hardiness zones 4-9

I hate to imply that fennel is an all-around bad neighbor, but it is. Fennel is one of those plants that you really should grow in a pot where it can’t negatively impact those around it. It’s great for attracting swallowtail butterflies as a larval host, but it has a negative impact on most other plants.

Fennel is allelopathic, which means that the roots produce a chemical that inhibits the growth and germination of other plants, including cucumbers. For this reason, keep it out of the vegetable garden and give it space away from other plants. 

Squash

	botanical name Cucurbita spp.
	sun requirements Full sun
	height Up to 20’
	hardiness zones 2-11

Squash is another close relative of cucumbers, and I’m sure you remember what that means. These two will compete for nutrients like nitrogen in the soil. They will also compete for water, leaving them both awfully thirsty. 

In addition to their similar nutrient needs, they have similar pests and diseases, which have a negative impact. The cucumber beetle will come for both of them. They also cross-pollinate, which isn’t good if you’re hoping to gather seeds for next year’s garden. 

Tomato

	botanical name Solanum lycopersicum
	sun requirements Full sun
	height 3’-10’
	hardiness zones 2-11

These aren’t the worst of companions, but planting cucumbers with tomatoes is typically not recommended. They’re both heavy feeders, so there is competition for resources, for one thing. They also share some common diseases, and you can end up with two ruined crops instead of one in this way.

Another reason to keep them separate is that cucumber vines are fast-growing and can easily overtake and overwhelm tomatoes. If you do plant them next to each other, make sure to give them both adequate support and space to spread out. 

Broccoli

	botanical name Brassica oleracea var. italica
	sun requirements Full sun
	height 1’-2’
	hardiness zones 2-11

These two crops rarely grow well together. Broccoli prefers cool weather, while your cucumbers like the heat. They are both heavy feeders and will compete for space and resources. Cukes need to spread out, and they can overwhelm and cast a shadow on your broccoli. 

These two attract some of the same pests, which isn’t great for either of them. In general, brassicas are heavy feeders that don’t make good neighbors for anything that competes for nutrients. 

Rosemary

	botanical name Salvia rosmarinus
	sun requirements Full sun
	height Up to 4’
	hardiness zones 8-10

Rosemary is similar to sage in growth habit and needs. It prefers drier, well-drained soil and is adaptable to poor or sandy soil. This doesn’t pair well with cucumber’s high water needs and need for rich soil. These don’t pair well with one another.

There is also the issue of aromatic herbs, which often influence the flavor of the vegetables you plant nearby. Personally, I love the flavor of rosemary, but it’s not for everyone. Aromatic herbs can sometimes inhibit the growth of other plants, too. 

Basil

	botanical name Ocimum basilicum
	sun requirements Full sun
	height 1’-3’
	hardiness zones 3-11

Basil is one that most folks are on the fence about. It makes an excellent companion for tomatoes, which take on some of basil’s flavor. What herb and veggie combo is better than tomato and basil? However, you may not want other vegetables to take on that flavor. 

Basil and cucumbers may compete for resources and potentially interfere with each other’s growth. Basil can be a decent pest control agent, but the benefits might not outweigh the risks. 

Mint

	botanical name Mentha spp.
	sun requirements Full sun
	height Up to 3’
	hardiness zones 3-11

Mint is a terrible neighbor. There, I said it. There really is no way around the fact, because mint is an aggressive spreader; it easily overtakes and outcompetes other plants. It will overgrow its space and steal water and nutrients that your cukes need.