While cucumbers can survive with just light, air, water, and soil, they can perform even better when paired with a companion plant. Yes, you heard that right! Cucumber companion plants, or intercrops, are essential in boosting yields and improving the plant's defense against harmful microorganisms. As they grow through life, a healthy relationship is maintained with their companion plants instead of a toxic one (*sighs in human problems*), allowing them to share crucial resources. This concept is scientifically backed and is one of the fundamental principles that a novice grower should know when gardening.
Whether you are new to cultivating plants, an adept grower seeking to learn what to grow with cucumbers, or just happened to land on our page randomly, we invite you to join our botanical adventure in the world of cucumber companion planting!
Benefits of Companion Planting
As previously mentioned, companion planting is a well-studied field in agriculture, with empirical-based evidence on its benefits. Companion plants for cucumbers are known to:
Core Principles of Cucumber Companion Planting
Companion planting for cucumbers is not simply about stuffing rows of plants in between, but it has an underlying purpose and core principles, such as the following:
- Plant crops of a different family. The first guiding principle of cucumber companion planting is to never plant a crop that belongs to the same family. Squash, pumpkin, watermelon, melon, gourds, or zucchini as a cucumber companion is a no-no. It can invite specialist or single-diet insects to feast on.
- Plant in between rows and with the proper spacing. Cultivating in alternating single rows, rather than in groups (one entire bed of vegetables), is like a maze run for insects. It makes their food hard to find. Also, you don't want your crops grown shoulder to shoulder! It minimizes airflow and could be a breeding ground for pathogenic molds.
- Remember commensalism or mutualism relationships. Recalling 3rd-grade science class, commensalism, and mutualism is an ecological relationship where one organism relies on another without affecting the other, or both parties have benefits. A companion plant for cucumber also sticks to this principle, either by giving nutrients without expecting anything in return, or just a mere shade would make it happy!
- Consider root depth and plant height. The canopy size and root extent are similar to the previous principle. The above-ground growth should not cast a shadow on the cucumber canopy, or else it may affect photosynthesis. The same is happening subterraneously. For instance, the lettuce root system expands on average to 6 inches (15 cm), while cucumbers' can penetrate twice or thrice, making both parties unaffected.
- Aromatics. Does the plant have a strong smell? If yes, this can be planted along with cucumbers. The fragrant aroma comes from the volatile organic compounds (VOCs) of plants, which have pest-repelling qualities. However, some gardeners claim it affects the flavors of cucumbers. While there is insufficient evidence to support this claim, it would be best to flag overly fragrant herbs as "what not to plant with cucumbers."
What is the Best Companion Plant for Cucumbers?
It is pretty hard to select the best companion plant for cucumbers because each one has a specific advantage and purpose, depending on the grower's goal. However, fertilizer-wise, green beans or legumes are the best companion plants. Your cucumber will not need an additional nitrogen source because legumes have a symbiotic relationship with a bacterium that can fix nitrogen. Plants cannot absorb atmospheric nitrogen (N2) and need some help from this microorganism to convert it into ammonia (NH4+), which is the form that plants can absorb.
The Most Beneficial Outdoor Cucumber Companion Plants
Vegetables
Beans
Are green beans and cucumbers companion plants? The answer is a big YES! Not just this protein-packed veggie, but any legume is compatible with cucumber. The roots of green beans and legumes, in general, harbor a bacterium species that can transform atmospheric nitrogen into a usable form for cucumbers. In English, it's free fertilizer!
Plant the beans at the same time as planting cucumbers and maintain at least 15 cm (6 inches) gaps between the rows.
Sweet Corn
Worry no more about installing a trellis, as corn stalks can work like one! Their trailing stem can climb up to the long corn stalk as the cucumbers grow. In return, cucumbers can suppress weed growth and conserve water.
Sow your corn two weeks before planting cucumbers 12 inches (30 cm) from the adjacent row. When the corn stems are roughly 3 feet (1 meter) tall, train the vines by twisting them around the stalks.
Radish
Radish and cucumbers are a great duo in your garden! Radish emits a disagreeable odor to cucumber beetles–one of the primary enemies of the green vegetable. At the same time, radishes get a free pest service too! Cucumbers can also help repel pests.
Sow radishes synchronously with cucumbers, and once sprouted, it's ready to be planted outdoors. Leave approximately half a meter (18-20 inches) between rows of cucumber and radish.
Carrot
Thinking about the delicious orange root crop as a candidate companion plant for cucumbers? Go ahead! Carrots send their taproot straight to the soil, which will soon expand and grow in size. However, it will not spread and invade the nearby cucumber's roots, avoiding competition.
After the green vegetable has been established from transplanting, sow carrots 30-40 cm (12-16 inches) apart from trellised cucumbers.
Pepper
Pepper and cucumber make a great pair because of their different growth habits: peppers grow a low bushy structure without affecting the neighbors, while the refreshing vegetable silently entangles itself with the trellis. Deep under the soil, cucumbers are protected from nematodes (worm-like microscopic pathogens that feed on roots and cause yield decline) when planted near hot pepper.
Transplant 4 weeks old seedlings one month later after the cucumbers were planted. Remember to observe the 40-45 cm (15-18 inches) distance from cucumber rows!
Transplant 4 weeks old seedlings one month later after the cucumbers were planted. Remember to observe the 40-45 cm (15-18 inches) distance from cucumber rows!
Herbs
Onion
One of the principles of companion planting is to plant aromatics, and onions stick to that rule! Its pungent smell thwarts off insect pests like aphids, beetles and animal pests like rabbits. Additionally, onion roots are shallow and do not encroach on the cucumber's root territory, maintaining diplomatic relationships among them.
Dill
Take the deal with dills; it is a good companion crop! It is armed with a strong odor that makes the pests turn away but also attracts garden friends. Beneficial insects are drawn into the plant's alluring flowers and will have a side visit to feed on the significant problems of cucumbers, such as aphids, mites, thrips, and cucumber beetles.
Plant dills simultaneously as cucumber and space out 30-40 cm (12-16 inches) from nearby cucumber rows.
Garlic
Garlic is a widely-known pest deterrent in organic gardening. It can be inserted between the cucumber rows, even in tight spaces. A study has also shown that garlic intercropping with cucumber can improve the soil nutrient status: another hidden wonder of planting the fragrant herb!
Start by planting garlic cloves in the fall. During spring, sow cucumber in rows with a distance of 10-12 cm (4-5 inches) apart from the garlic.
Oregano
Like other herbs, oregano joins the plant platoon using its strong scents that help defend your cucumber against pests. Siphoning insects like aphids and voracious squash beetles are unlikely to land on your precious crop. And as a bonus, you have extra herbs for your pasta!
Begin seeding oregano during the trellising phase of your summer veggie. Plant it approximately 35-45 cm (14-18 inches) from the neighboring cucumber strip.
Celery
Celery is a great companion vegetable prized for its strong herby and pungent taste. Because of this smell, the main enemies of cucumbers, like whiteflies and aphids, would dare to feed on the foliage. A study also demonstrated that the celery-cucumber combo induces resistance against fusarium wilt: a damaging fungus in large-scale cucumber patches.
Sow celery indoors for 4-6 weeks before cucumbers and transplant them together outdoors. Put a distance of at least 15 cm (6 inches) between celery and cucumber rows.
Flowers
Marigold
Marigold is considered gold when planted in a company with cucumbers. Its eye-catching flowers adorn your vegetable patch and will also attract beneficial insects like parasitic wasps, butterflies, lady beetles, and bees. The roots also serve another function, reducing underground diseases such as root knot nematodes which cause sudden wilting and consequent yield decline in cucumbers.
Seed marigolds at the same time as cucumbers in early spring. If you have French marigolds, maintain a 20-25 cm (8-10 inches) distance from the row of the main crop; make it 45-50 cm (18 inches) if you plant African marigolds.
Sunflower
Sunflowers are spectacular plants that remind us of summer and are highly compatible with the summer crop, cucumbers! Its extended stalk functions as a living trellis, while the tempting flowers are always a treat for bees, parasitic wasps, and other natural enemies of cucumber pests. A study also has revealed another interesting group of insect predators: birds!
Like corn, sow sunflower seeds 2 weeks ahead of cucumber to take advantage of its trellising service.
Nasturtium
Nasturtiums are stunning flowers and delicious too! They can be added to your salad or cheese sandwich. Pollinators will surely get abuzz in your garden because of its irresistibly attractive flowers. And if you're tired of leaf-perforating cucumber beetles, nasturtiums act as a trap crop. Rather than eating the star of the garden, it gets lured more by its companion.
Plant nasturtiums simultaneously as cucumber, following a distance of 30 cm (12 inches) between each row.
Chrysanthemum
One of the earliest pesticidal compounds was discovered in chrysanthemums, and for this reason, planting next to cucumbers can help combat unwelcome insects. Aside from the upper-ground benefits, it can enhance soil microbial activity, promoting growth.
Chrysanthemums are often perennials or plants that can grow year after year, so it would be best to plant them outside your annual vegetable patch, like cucumbers.
Calendula
Calendulas produce bright yellow to orange flowers that are alluring to pollinators and natural pest enemies like lacewings and hoverflies. Additionally, you do not need to worry about fertilizing your cucumber companion. It can thrive and produce flowers even in relatively infertile soil!
Calendula can be sown together with cucumber observing a planting distance of 15-30 cm (6-12 inches) between rows.
Companion Plants for Cucumbers in Containers
What if you don't have a spacious backyard? You can still do companion cropping with container gardening! Here is a list of what grows well with cucumbers:
Lettuce
Lettuce is such a perfect match for cucumbers! Their roots do not interfere with each other, avoiding possible competition. Plus, lettuce has a short life cycle and can be harvested for 4-6 weeks, which is way more advanced than cucumbers. If you want to simultaneously harvest lettuce cucumber for your salad, transplant lettuce in the same pot when cucumbers flower.
Chives
Another neutral partner that will do well with container gardening is chives and cucumber! Chives are easy to maintain, take little space and have superficial roots. The herb will take care of the pest control service without demanding any return in cucumber. You can plant it around the cucumber sapling at the same time in the pot.
Beetroot
Looking for a versatile vegetable that can be a good companion with cucumbers? Beetroot is the way to go! The leaves, rich in antioxidants, can be consumed as salad or sauteed. If you want the root crop, you will need at least 50-70 days, depending on the variety. Because cucumbers and beetroots have almost the same growing period, start seeding or transplanting all at once in the shared container.
Mistakes to Avoid in Your Cucumber Companion Planting
Can I Plant Cucumbers near Raspberries?
Yes, you can companion plant cucumbers with raspberries, but you need to be aware of possible mistakes in cucumber companion planting in general, such as the following:
- Planting crops of the same family. One big no in intercropping cucumbers is planting a species belonging to the same family (Cucurbitaceae), including squash, pumpkins, watermelon, and melon. They produce identical "scents" which are attractive to pests. It is like an insect food buffet for them!
- Incorrect planting distance. Companion planting only works by observing proper space. Planting too close creates a perfect haven for fungus to thrive! If you plant too far apart, your garden space is not efficiently utilized.
- Wrong timing. Synchronously planting your cucumber with its companion is crucial. For instance, if you plant your corn too late, the trailing vegetable may be overgrown and will crawl on the soil instead, predisposing itself to soil-borne pathogens.
- Planting competitive crops. There are many types of competition in the botanic world. Plants battle for sunlight, space, water, and nutrients. Some plants from the cabbage family (Brassicaceae) secrete inhibitory substances (allelochemicals) that impede the growth of the neighboring crops and allow them to dominate the spot. So, the trick is to know thy neighbor!
- Improper watering and fertilization. Although reduced watering and fertilization are promising advantages of companion cropping, it does not mean NO food and water! If you use a well-draining substrate, irrigate during the first 2-4 weeks of planting. Once established, you may reduce the volume and frequency of watering. And, unless legumes are involved in companion planting, your crop will likely need additional soil food!
What You Can't Plant with Cucumbers
Not all cucumbers companion plants are compatible for the reason that losses may incur rather the additional benefits. Avoid the possible mismatch by knowing the following plants:
Peppermint
Many gardeners have firsthand experience that planting peppermints and other strongly scented herbs can influence the flavor of cucumbers. This is still an open discussion of the science of agriculture. However, if you dislike the taste of herbs in your cucumber, it would be safe to cross out peppermint and other strongly flavored plants in the list of cucumber plant companions.
Melon
Melons, along with hard-skinned cucurbits like pumpkins, squash, zucchini, and watermelon, can spell a pest epidemic if planted together with cucumber. The volatile organic compounds or the "scents" of these crops are amplified and simply saying, "hey, the food is ready!" to bugs like aphids, cucumber beetles, seedcorn maggots, squash bugs, squash vine borer.
Brassica
Brassicas are plants belonging to the cabbage family, including cauliflower, broccoli, and mustard. They can attract pests where cucumbers are susceptible. In addition, brassicas are heavy drinkers that may deprive your cucumber patch of precious resources. So to be safe, this group of plants should be off the list.
FAQ
Can I Plant Cucumbers next to Raspberries?
Yes, you can! They belong to different plant families, making them less prone to attack by the same pest and diseases. The only thing to avoid is planting raspberries with the nightshade family, including peppers, eggplants, and tomatoes.
Are Green Beans and Cucumbers Companion Plants?
Yes, green beans are such a perfect match with cucumbers! Green beans house nitrogen-fixing bacteria within their roots and can share some surplus nutrients with their neighboring plant without affecting their growth.
