Nasturtiums bring a bright, cheerful vibe to any garden, but I learned the hard way that some plants just don’t get along with them.
Mixing the wrong neighbors can lead to crowded roots and unhappy blooms. After a few experiments, I figured out which plants to keep far away—and which ones make perfect companions.
These 14 plants are best avoided near nasturtiums, but don’t worry, I’ve got some great alternatives to suggest. Let’s help your nasturtiums shine without the drama!
1. Tomatoes
Growing tomatoes near nasturtiums creates a battle for nutrients in your soil. These hungry plants compete for the same resources, leaving both struggling to thrive in the shared space.
You might notice stunted growth and reduced fruit production in your tomato plants. Nasturtiums can also create too much shade for shorter tomato varieties, blocking essential sunlight they need for proper development.
2. Beans
Bean plants and nasturtiums simply don’t play well together in the garden. Both are climbers that will tangle and compete for the same vertical space, creating a messy, unproductive tangle.
The sprawling nature of nasturtiums can quickly overwhelm young bean seedlings. Additionally, these plants attract similar pests, potentially concentrating problem insects in one area of your garden.
3. Cabbage
Surprisingly, cabbage and nasturtiums make poor garden companions despite both being members of the Brassicaceae family. When planted together, they compete for similar soil nutrients, resulting in smaller, less flavorful cabbages.
They also attract the same pests, creating a pest magnet area in your garden. The sprawling growth habit of nasturtiums can overshadow young cabbage plants, preventing proper development and head formation.
4. Squash
Squash plants require ample space to spread their large leaves and vines. When nasturtiums grow nearby, both plants compete for ground space, creating a crowded, tangled mess that’s difficult to manage.
The dense foliage creates humid conditions that can promote powdery mildew and other fungal diseases. Both plants also attract similar pollinators, which might seem good but can actually reduce the fertilization efficiency for both crops.
5. Potatoes
Potatoes develop best when they have loose, well-drained soil all to themselves. Nasturtiums’ shallow root systems can interfere with potato tuber development, resulting in smaller harvests and misshapen spuds.
The spreading habit of nasturtiums can also block sunlight from reaching potato plants. Many gardeners report that this pairing leads to increased pest problems, particularly with aphids that can transmit diseases between the plants.
6. Fennel
Fennel is known as the antisocial plant of the garden for good reason. It releases compounds that inhibit the growth of many plants, including nasturtiums, causing them to wilt and produce fewer flowers.
The tall structure of fennel also creates shade that nasturtiums don’t appreciate. For best results, keep these two plants in completely separate areas of your garden, as even nearby planting can cause problems.
7. Zucchini
Zucchini plants need plenty of room to spread their large leaves and develop properly. When nasturtiums grow too close, both plants suffer from overcrowding and compete for water and nutrients.
The dense plant coverage creates humid conditions that promote fungal diseases. Zucchini plants also produce better when they have full sun exposure, which can be blocked by the spreading nasturtium vines.
8. Mint
Mint is an aggressive spreader that will quickly overtake nasturtiums in the garden. Its invasive root system steals water and nutrients from nearby plants, leaving nasturtiums struggling to survive.
The strong aromatic oils in mint can also interfere with the natural pest-repelling qualities of nasturtiums. If you love both plants, keep mint contained in pots far away from your nasturtium patch.
9. Oregano
Oregano prefers dry, Mediterranean-like conditions, while nasturtiums thrive with regular moisture. This fundamental difference in water needs makes them incompatible garden neighbors.
When planted together, either the oregano suffers from too much moisture or the nasturtiums wilt from drought. The strong essential oils in oregano can also interfere with the growth patterns of nasturtiums, resulting in fewer flowers and less vigorous plants.
10. Rosemary
Rosemary’s woody structure and preference for dry, well-drained soil clash with nasturtiums’ need for consistent moisture. When planted together, one or both plants will show signs of stress due to improper watering conditions.
The strong aromatic oils in rosemary can also suppress nasturtium growth. Gardeners often notice fewer nasturtium blooms and smaller leaves when these plants share space, making this pairing one to avoid.
11. Dill
Dill and nasturtiums compete for the same beneficial insects in the garden. When planted together, this competition can reduce the pest control benefits that nasturtiums naturally provide.
Dill’s tall stalks can also shade nasturtiums, preventing them from receiving adequate sunlight. As dill matures and self-seeds, it can quickly take over a garden bed, crowding out the more delicate nasturtium plants.
12. Sage
Sage requires dry, arid conditions that conflict with nasturtiums’ preference for moist soil. When grown together, either the sage suffers from root rot or the nasturtiums struggle with drought stress.
The strong aromatic compounds in sage can also interfere with the natural pest-repelling qualities of nasturtiums. These plants have such different growing requirements that pairing them creates unnecessary challenges for even experienced gardeners.
13. Cilantro
Cilantro bolts quickly in warm weather, while nasturtiums are just hitting their stride. This mismatched growing cycle means you’ll have flowering cilantro when your nasturtiums are still developing.
The bolting cilantro creates shade and competition during nasturtiums’ critical growth period. Cilantro also attracts different beneficial insects than nasturtiums, potentially confusing the natural pest control dynamics in your garden.
14. Marigolds
While both marigolds and nasturtiums are known as pest-repelling plants, they actually compete for the same role in the garden. When planted together, their similar pest-deterrent properties become redundant rather than complementary.
Both plants also attract the same beneficial insects, creating unnecessary competition. Garden space is better utilized by pairing each of these powerful pest-repellers with different companion plants to maximize their benefits.
15. Basil
Looking for a perfect partner for your nasturtiums? Basil is an excellent choice! Its aromatic oils deter pests that might damage nasturtiums, while nasturtiums repel insects that typically bother basil.
This mutually beneficial relationship creates stronger, healthier plants. Basil’s upright growth habit also complements nasturtiums’ sprawling nature, making efficient use of garden space while creating a visually appealing planting combination.
16. Radishes
Radishes make exceptional companions for nasturtiums in the garden. Their quick growth cycle means they can be harvested before nasturtiums fully spread, making efficient use of garden space.
Nasturtiums help deter flea beetles that often plague radishes. As an added bonus, both plants have edible parts – you can enjoy peppery radish roots and add nasturtium flowers and leaves to salads for a similar spicy kick.
17. Cucumbers
Wait – didn’t we just say cucumbers don’t pair well with nasturtiums? That’s only true when they’re planted directly together! When nasturtiums are strategically placed nearby (but not intertwined), they act as a trap crop for aphids that would otherwise attack cucumbers.
Plant nasturtiums about two feet away from cucumber vines for best results. This arrangement provides pest protection while avoiding direct competition for space and nutrients.
18. Lettuce
Lettuce and nasturtiums form a mutually beneficial garden partnership. Nasturtiums’ spreading habit provides gentle shade for lettuce during hot weather, helping prevent premature bolting and bitter leaves.
The bright nasturtium flowers also attract pollinators and beneficial insects to your garden. As an added bonus, you can harvest both plants for a colorful, peppery salad – nasturtium flowers make an eye-catching edible garnish!
19. Broccoli
Broccoli plants benefit tremendously from having nasturtiums as neighbors. Nasturtiums act as a trap crop for aphids and cabbage worms that would otherwise attack your broccoli heads.
The bright flowers also attract beneficial insects that prey on garden pests. Plant nasturtiums around the perimeter of your broccoli patch for maximum protection without competition for growing space or nutrients.