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Companion planting cucumbers is essential in the organic garden. Planting cucumbers alongside the right plants helps ensure you get a bigger, better harvest of healthy, tasty cucumbers. Interplanting cucumbers keeps the plants healthier and more resistant to pests and diseases, so they produce a better crop and stay productive for longer. My favorite picks for cucumber companion plants are:
- Beans
- Corn
- Marigolds
- Sunflowers
- Radishes
- Dill
- Nasturtium
My regular readers know that companion planting is an obsession of mine. It’s one of my favorite methods of natural pest control, attracting pollinators, improving soil and plant health, increasing biodiversity, and getting bigger harvests. And for cucumbers, which are pretty delicate and get attacked by a lot of pests and diseases, using cucumber companion plants can help save your harvest.
I’m also including the plants you should never plant with cucumbers:
- Potatoes
- Melons
- Aromatic herbs
Understanding Companion Planting
Companion planting is a time-tested gardening method that puts the concept of plant community into practice. The three sisters method is an ancient and very effective example.
Interplanting the right combination of plants in your vegetable garden can increase yield and improve plant health, vitality and vigor. Plus, good companion plants can deter pests, improve growing conditions for one another, and attract predators to further eliminate those same pests you’re trying to deter.
Scientifically, companion planting works for a few reasons. Certain plants can enrich the soil with nutrients that others need. Some plants may attract beneficial insects, while others repel harmful pests. And in a practical sense, companion planting can make excellent use of garden space.
Why Companion Planting is Beneficial for Cucumbers
Pairing cucumbers with the right companions can bring a plethora of benefits. For one, some plants can boost cucumber crop growth and yield, either through improved soil conditions or enhanced pollination. Additionally, certain plants can repel pests that typically plague cucumber plants, acting as a natural pest control measure. And many gardeners will tell you, myself included, that the best companion plants for cucumbers can even enhance the flavor.
Top Companion Plants for Cucumbers
Here are my top tried and tested cucumber companion plant choices. These are my go-tos every growing season.
Beans: The Nitrogen-Fixing Companions
Beans and other legumes, like peas and lentils, are nitrogen fixers, which make them perfect companion plants for cucumbers and many other nitrogen-loving plants.
But what does that really mean?
Nitrogen is a fundamental component of amino acids, proteins, and nucleic acids, including DNA, and is therefore crucial for life. However, even though the atmosphere is about 78% nitrogen, most plants can’t utilize nitrogen directly from the air because it’s in a form (N2) that is not easily accessible. This is where the magic of beans and other legumes comes into play.
Beans and other legumes have a symbiotic relationship with a type of bacteria called Rhizobium. These bacteria infect the roots of the bean plants and form nodules, where they convert atmospheric nitrogen into ammonia, a form that plants canuse. This process is known as nitrogen fixation.
So, when you plant pole beans (or bush beans or field beans) next to cucumbers, they’re doing more than just sharing space. The nitrogen-fixing bacteria in the roots of the bean plants are working away, converting nitrogen from the air into a form that plants can use to grow. As the bean plants grow and shed leaves, or when the plants die off and decompose, this nitrogen is released into the soil.
This additional nitrogen supply is a boon for nearby plants. Cucumbers are heavy feeders, meaning they require a lot of nutrients to grow successfully, and nitrogen is one of the key nutrients. It’s vital for leaf and stem growth, and it also plays a crucial role in the production of chlorophyll, which plants use to photosynthesize and produce energy. You can learn more about cucumber growth stages here.
Companion planting beans and cucumbers is a perfect example of how interplanting leverages the natural abilities of certain plants to create a more productive and harmonious garden.
Corn: Providing a Canopy for Cucumbers
Corn, with its towering stature and lush, broad leaves, is not just a delightful crop to grow, but it can also serve as a beneficial companion for cucumbers.
Cucumbers, while sun-loving, are sensitive to intense, direct sunlight. Extended exposure to harsh sunlight can cause the leaves of cucumber plants to scorch, wilt, or even bleach out, losing their vibrant green color. This can weaken the plants, reducing their productivity and making them more susceptible to diseases.
Due to their height and large leaves, corn plants create natural, living sunshade for plants growing beneath them. When planted strategically, they can protect cucumber plants from harsh direct sun. The tall corn stalks allow cucumbers to enjoy the morning sun, but shield them from the intense afternoon rays. This creates a cooler, more hospitable microclimate for cucumbers, helping them thrive.
And, because cucumbers are vining plants, a corn stalk can serve as a natural trellis for cucumber vines to save space and provide better air circulation around plants, which can help prevent fungal diseases.
Marigolds: The Flowering Guardians of Cucumbers
Marigolds, known for their vibrant orange and yellow blooms, are more than just eye-candy in your garden. They carry potent abilities that make them fantastic companions for many vegetable plants, including cucumbers.
Among the potential threats to cucumber plants are various pests, including harmful nematodes (microscopic worms that live in the soil) and cucumber beetles. Nematodes can damage the cucumber roots, inhibiting nutrient uptake and potentially introducing diseases. Cucumber beetles chew on leaves, flowers, and fruits and transmit bacterial wilt and cucumber mosaic virus.
Enter marigolds. These cheery flowers can deter both nematodes and cucumber beetles, providing a protective shield for your cucumbers. The roots of certain marigold varieties release a substance that’s toxic to many nematodes. Planting marigolds in your cucumber bed can reduce the population of harmful nematodes in the soil helping to protect your cucumbers from root damage.
As for cucumber beetles, they dislike the strong smell of marigolds. Intercropping marigolds with cucumbers can therefore deter these beetles, minimizing their damage to your cucumber plants.
Marigolds also attract a wide range of beneficial insects to your garden, including pollinators like bees and butterflies, and predatory insects like ladybugs, parasitic wasps, and lacewings that feed on various garden pests, including aphids and tomato hornworms.
Despite all their benefits, marigolds require minimal care, making them an easy addition to your cucumber garden. Just ensure they get plenty of sun, and they’ll happily stand guard over your cucumbers.
Sunflowers: The Towering Protectors of Your Cucumber Patch
Sunflowers, with their vibrant, sunny faces and skyscraper-like stems, are not just a sight for sore eyes but also robust companions for many plants, including cucumbers.
As they grow, sunflowers can reach impressive heights, which can be beneficial to cucumber plants for a couple of reasons. Firstly, similar to corn, sunflowers can provide a degree of shading for cucumbers. Despite being a warm-weather crop, cucumbers can be sensitive to prolonged, intense sunlight, especially during peak summer. In this scenario, the towering sunflowers can offer respite, casting a dappled shadow over the cucumbers during the harshest part of the day. This helps to create a microclimate that’s cooler and more suited to the cucumber’s needs, aiding their growth and overall health.
Another valuable benefit of sunflowers is their ability to act as a decoy for certain pests. Sunflowers are known to attract a variety of insects, including aphids and ants, which can be harmful to cucumbers. By luring these pests away, sunflowers can effectively reduce the damage caused to cucumbers. As an added bonus, the insects attracted to sunflowers can serve as a food source for beneficial predatory insects, like ladybugs and lacewings, thereby increasing their presence in your garden and further enhancing natural pest control.
And, sunflowers, with their strong, sturdy stems, can serve as natural trellises for cucumber vines, just like corn.
Radishes: Small But Mighty Defenders Against Cucumber Beetles
Often enjoyed for their crisp texture and peppery flavor, radishes also pack a punch when it comes to defending your garden, especially cucumber plants, against certain pests. One such pest is the cucumber beetle, a common nuisance for cucumber growers.
Cucumber beetles are small insects that can cause significant harm to cucumber plants. They eat all parts of the plant
It turns out that cucumber beetles are not fans of radishes. The exact reason for this aversion isn’t fully understood, but it’s suspected that the strong odor and flavor of radishes may act as a deterrent. By planting radishes in and around your cucumber patch, you can make the area less appealing to these destructive beetles, reducing their presence and thus the potential damage to your cucumbers.
Aside from their pest-deterrent properties, radishes have a quick growth cycle and can be harvested just a few weeks after planting. This makes them a great option for succession planting and ensuring continuous coverage throughout the growing season. Plus, their small size and shallow roots mean they won’t compete heavily with cucumbers for space or nutrients.
Remember, not all radish varieties may be equally effective at deterring cucumber beetles, so you may need to experiment a bit to find what works best in your garden. With their dual role as a delicious root vegetable and a guardian of cucumber plants, radishes certainly earn their place in the companion planting hall of fame.
Dill
Dill, known for its feathery leaves and distinct aroma, is a common herb used in various cuisines. However, in the garden, dill plays a role that’s just as important: attracting beneficial insects that can boost your cucumber yield.
One of the essential stages in the life cycle of any flowering plant, including cucumbers, is pollination. Without it, your cucumber flowers won’t be able to develop into the crunchy fruits we all enjoy. Unless, of course, you’re growing parthenocarpic cucumber varieties. This is where dill can provide significant assistance.
Dill flowers attract a variety of pollinators, including bees and butterflies. These insects play a crucial role in plant reproduction by transferring pollen from the male parts of a flower to the female parts. By planting dill in your cucumber garden, you’re effectively setting out a welcome sign for these pollinators. The more pollinators that visit your garden, the higher the chances of your cucumber flowers being successfully pollinated, which can lead to a more abundant cucumber harvest.
In addition to pollinators, dill also attracts a whole host of predatory insects that are beneficial for your garden. These include ladybugs, lacewings, and parasitic wasps, all of which feed on various garden pests. By inviting these insects into your garden, you’re establishing a natural form of pest control. This can help maintain a healthy balance of insects in your garden and prevent any one species from becoming a significant problem.
When planting dill as a companion to cucumbers, it’s important to consider its growth habit. Dill can become quite tall and may need staking to prevent it from falling over. Ensure it’s planted in a location where it won’t overshadow your cucumber plants too much and inhibit their access to sunlight. Also, dill can self-seed prolifically, so you may want to harvest the seeds before they disperse if you wish to limit its spread in your garden.
Nasturtium: The Colorful Trap for Aphids
Nasturtiums, with their bold, vibrant blooms, are an attractive addition to any garden. But beyond their visual appeal, these flowers carry a special utility in the realm of companion planting. They can act as an effective “trap crop” for aphids, offering a protective shield for your cucumber plants.
Aphids, tiny insects that feed on plant sap, can pose a significant threat to cucumbers. Aphid infestations can weaken plants by depriving them of vital nutrients. Additionally, aphids can spread plant diseases and encourage mold growth by excreting a sticky substance known as honeydew. Which also encourages ants who in turn farm the aphids in a bizarre and macarbe example of mutualism.
Nasturtiums, however, have an irresistible allure for aphids. Aphids are attracted to nasturtiums even more than they are to cucumbers. By planting nasturtiums, you can draw aphids away from your cucumbers and toward the nasturtiums instead.
This strategy makes nasturtiums a sacrificial or “trap crop,” luring aphids away from your precious cucumber plants. Once the aphids have gathered on the nasturtiums, you can leave them be or employ natural aphid control methods to eliminate them.
The trick is to plant them close enough to your cucumbers to attract the aphids, but not so close that the aphids can easily hop over to your cucumber vines.
Besides their role as a trap crop, nasturtiums have other benefits too. Their vibrant flowers can attract a variety of pollinators to your garden, aiding in the pollination of your cucumber flowers. Plus, nasturtiums are edible plants with a peppery flavor similar to watercress. Both their leaves and flowers can add a colorful, tasty punch to salads. Only the healthy, not-covered-in-aphids plants, though.
Plants to Avoid Near Cucumbers
Just as some plants are beneficial, others are best kept at a distance from your cucumbers.
Potatoes
Cucumbers and potatoes are not the best companions in the garden for a couple of reasons. Firstly, both plants are heavy feeders. This means they both need a lot of the same nutrients, especially potassium and nitrogen, to grow well. If planted too close together, they can compete for these essential nutrients, leading to potential deficiencies and less productive plants.
Secondly, potatoes are susceptible to a type of fungal disease known as late blight, which causes dark, water-soaked spots on leaves, stems, and potato tubers. Unfortunately, this disease can also infect cucumber plants and be even more damaging to them. The spores of the late blight fungus are typically carried by wind and rain, so if an outbreak occurs in your potato plants, it can quickly spread to your cucumbers if they’re nearby.
Aromatic Herbs
Aromatic herbs are a wonderful addition to any garden – they make great companions for many other plants, but not cucumbers. And you can’t beat the flavor of fresh herbs picked straight from the garden. I adore my beautiful herbs like sage, basil, and rosemary.
However, when planning your cucumber garden, it’s important to note that not all herbs make good neighbors for your cucumbers.
Sage and basil, along with several other herbs, are known to have allelopathic properties. This means they can release compounds into the soil that inhibit the germination and growth of other plants. While this trait can be useful in some circumstances, such as deterring certain pests or weeds, it can also pose a challenge for companion plants like cucumbers.
Sage, a perennial herb known for its earthy flavor and strong aroma, may deter pests in the garden, but it could also negatively affect the growth of cucumbers planted nearby. Similarly, basil, despite being a common companion for tomatoes, may not be as compatible with cucumbers.
While the effect of these herbs on cucumbers may not be dramatically harmful, it’s generally recommended to plant them separately to avoid any potential growth inhibition. This way, you can enjoy the benefits of growing both flavorful herbs and juicy cucumbers in your garden, without them interfering with each other’s health and productivity.
However, not all herbs are bad companions for cucumbers. Dill, for instance, is a great companion for cucumbers, as it attracts beneficial insects that can help pollinate cucumber flowers. Similarly, parsley can attract predatory insects that feed on common cucumber pests.
Melons
Melons and cucumbers may both belong to the Cucurbitaceae family, but that doesn’t mean they should be planted too close together. Cross-pollination between cucumbers and melons could potentially lead to less-than-desirable results.
Cross-pollination occurs when pollen from one plant’s flower is transferred to another plant’s flower, usually by wind or insects like bees. While this process is necessary and beneficial for plant reproduction, it can lead to issues when two different species interbreed.
In the case of cucumbers and melons, cross-pollination might not affect the fruits that appear in the current growing season. However, if you plan to save seeds from these fruits for future planting, you might encounter some issues. Seeds from the fruits of cross-pollinated plants can yield offsprings with unpredictable and often inferior qualities. For example, a cucumber plant grown from a seed cross-pollinated with a melon might produce fruit that is oddly shaped, poor in taste, or less vigorous overall.
It’s also worth noting that while cross-pollination is a concern if you’re saving seeds, if you’re purchasing new seeds each year, it’s less of an issue. Also, cross-pollination can only occur between closely related species. So, while cucumbers and melons could potentially cross-pollinate, other plants in your garden, like tomatoes or peppers, would not cross-pollinate with cucumbers.
How to Implement Companion Planting in Your Garden
You’re almost ready to start companion planting! Remember to plan your garden layout thoughtfully to allow each plant enough space to grow. Understanding plant growth habits, such as their size, root depth, and sun requirements, can help you decide where to place them. And consider timing: planting companion plants at the same time as your cucumbers can help them establish a mutually beneficial relationship early on.
Troubleshooting Common Issues in Companion Planting
Even with careful planning, issues may arise. If pests unexpectedly appear, identify the pest first, then consider introducing more of their natural predators into your garden, or try a different companion plant. If your cucumbers or companion plants show signs of nutrient deficiency, a good organic compost or fertilizer might be the answer.
FAQS
Yes, cucumbers and tomatoes can generally coexist well, although it’s important to give each enough space and ensure they don’t shade each other out.
Absolutely! Just ensure your container is large enough to support multiple plants and their root systems.
You might want to trim back your companion plants if they’re outgrowing your cucumbers to ensure all plants have equal access to sunlight.
While it can significantly reduce pest issues, companion planting isn’t a 100% guarantee. It’s one tool among many in an organic gardener’s toolbox for managing pests.