Emily ParkerBy Emily Parker

Updated November 2026

Companion planting with nasturtium is one of the easiest ways to add color, attract helpful insects and possibly reduce pest pressure in a vegetable garden. In this guide, you will learn which vegetables pair well with nasturtiums, how far apart to plant them, how to time sowing so they flower when you need them, and what mistakes to avoid. Nasturtiums are fast, forgiving and edible, so they suit beginners as well as experienced growers.

What Nasturtiums Do in a Vegetable Garden

Nasturtiums (Tropaeolum majus) are annual flowers with peppery leaves and blossoms that you can eat. Gardeners plant them mainly for three reasons. First, the open, single-petal flowers draw in pollinators such as bees and hoverflies. Second, nasturtiums are often used as a “trap crop” for aphids, which tend to cluster on the soft new growth and leave nearby crops alone for longer. Third, they act as ground cover in spots where weeds would otherwise take hold.

Shopping for one? See our guide: Companion Planting with Pole Beans: 5 Best Picks for 2026.

It helps to be realistic about these benefits. Trap cropping works best when you check the plants regularly and remove heavily infested stems. Nasturtiums will not stop a serious squash bug or cabbage worm outbreak on their own. Think of them as one useful layer in an integrated approach that also includes hand-picking, row covers and healthy soil. For a broader look at how pairings work, see What Does Companion Planting Mean? Pairings and Pitfalls.

Step 1: Choose the Right Nasturtium Type

Before you buy seed, decide whether you want a trailing or a bushy habit. Trailing types can spread 3 to 6 feet and work well at the edges of raised beds or in hanging baskets. Compact or dwarf types usually stay around 12 to 18 inches tall and fit inside a bed without crowding its neighbors. Both are common in seed catalogs, so read the expected height on the packet.

Step 2: Time Your Planting

Nasturtiums are frost-tender and grow best in warm soil. Direct-sow seeds 1 to 2 weeks after your last spring frost, once soil temperatures reach about 60°F. In most of the continental US that falls between early April and late May. Seeds germinate in 7 to 14 days. Plants generally begin flowering about 8 weeks after sowing, so starting them at the same time as your tomatoes or squash means flowers will appear as the main crop sets fruit.

If you want flowers earlier, start seeds indoors 3 to 4 weeks before your last frost in peat pots, since nasturtiums resent root disturbance. Harden them off for about a week before transplanting.

Step 3: Plan Spacing and Placement

Give nasturtiums room to spread without shading or overwhelming their neighbors. The table below offers starting points for common setups.

Nasturtium Type Plant Spacing Best Placement
Dwarf or compact 10 to 12 inches apart Corners of raised beds, between cabbage-family plants
Semi-trailing 12 to 18 inches apart Along the front edge of a bed
Trailing 18 to 24 inches apart Border, slope, or container edge where it can cascade

In a raised bed, a common approach is to plant one nasturtium at each corner and one or two along the sunny side. Keep them out of the center of a bed where they might compete with taller crops for light. For layout ideas, see Raised Bed Garden Layout Companion Planting: A Step-by-Step Guide.

Step 4: Pair Nasturtiums with the Right Crops

Nasturtiums are most often grown near the following crops.

  • Cabbage family (broccoli, kale, cabbage): Nasturtiums can draw aphids and cabbage whiteflies away from these crops. Check the undersides of nasturtium leaves weekly.
  • Cucumbers and squash: Pollinator-attracting flowers help fruit set, and trap-cropping may reduce early aphid damage on vine crops.
  • Tomatoes: Blooms attract bees and hoverflies. Keep nasturtiums a foot or more from tomato stems to avoid crowding.
  • Radishes and lettuce: Nasturtiums can serve as a leafy border that shades soil and reduces weed competition.

Some pairings call for caution. Avoid planting nasturtiums directly against crops that need full sun and lots of air movement, such as peppers grown in a dense bed. Watch for whiteflies, which can build up on nasturtium foliage and move to nearby brassicas if the nasturtiums are not monitored.

Step 5: Maintain and Manage Pests

Once established, nasturtiums need little care. Water deeply once or twice a week during dry spells, but avoid soggy soil, which can lead to root rot. Nasturtiums actually bloom more heavily in lean soil and tend to produce more leaves than flowers when fertilized with high-nitrogen feed, so skip heavy composting around them.

Scout the plants at least once a week. Use this checklist:

  1. Look under leaves and along young stems for aphid clusters.
  2. Crush small colonies by hand or rinse them off with a strong stream of water.
  3. Remove leaves with heavy whitefly activity or signs of fungal leaf spots.
  4. Pull and compost plants that are fully infested, then resow a fresh patch if you still want the trap effect.
  5. Leave some flowers in place to keep pollinators coming.

Common Mistakes to Avoid

  • Planting too close to the main crop. Trailing nasturtiums can smother seedlings. Keep a clear gap until your vegetables are established.
  • Overfeeding. High-nitrogen fertilizer produces lush leaves and few flowers, which reduces the pollinator benefit.
  • Ignoring the trap crop. If you never inspect nasturtiums, aphids will build up and then spread.
  • Assuming they replace other pest control. Companion plants support a garden but do not substitute for monitoring, row covers or crop rotation.
  • Letting them self-seed uncontrolled. Nasturtiums drop seed readily. Deadhead spent flowers if you want to limit volunteers.

Tips for Better Results

  • Use nasturtium blossoms and young leaves in salads, where their peppery flavor pairs well with greens and goat cheese.
  • Soak seeds in lukewarm water for 12 to 24 hours before sowing to speed germination.
  • Mulch lightly around the base of plants to keep soil moisture steady without rotting the stems.
  • Plant a few nasturtiums in a separate spot as a dedicated trap crop, so you can remove them without disturbing your main beds.

A few simple supplies make nasturtium care easier and help you keep beds productive.

  • Soil moisture meter: Helps you avoid overwatering nasturtiums growing in containers or raised beds. View on Amazon
  • Fine-mesh insect netting: Protects young cabbage-family plants while nasturtiums act as a trap crop nearby. View on Amazon
  • Hand pruners: Make it quick to remove infested stems and deadhead spent blooms. View on Amazon

FAQ

Do nasturtiums really repel aphids?

Not in the sense of a repellent. Nasturtiums tend to attract aphids, which is why they are used as a trap crop. The idea is that aphids settle on the nasturtiums instead of your main vegetables, and you can remove those colonies. Results vary by garden and season.

When should I plant nasturtium seeds?

Sow directly outdoors 1 to 2 weeks after your last spring frost, once soil reaches about 60°F. Seeds usually germinate within 7 to 14 days.

Are nasturtium flowers safe to eat?

Nasturtium flowers and leaves are commonly eaten in salads. Only eat plants grown without pesticides, and wash them well. If you have food allergies or concerns, check with a healthcare professional or a local extension office before eating garden plants.

How far apart should nasturtiums be planted?

Dwarf types need about 10 to 12 inches of space, semi-trailing types 12 to 18 inches, and trailing types 18 to 24 inches. Adjust based on the mature size listed on your seed packet.

Can nasturtiums grow in containers?

Yes. Trailing and compact varieties do well in pots at least 12 inches wide and deep. Use a well-draining potting mix and water when the top inch of soil feels dry.

Do nasturtiums attract pollinators?

They do, especially bees and hoverflies. Leaving some flowers open rather than deadheading everything helps keep pollinators visiting your garden.

Will nasturtiums spread through my whole garden?

They can self-seed, particularly trailing types. Deadhead flowers before seed sets if you want to limit volunteers, and pull unwanted seedlings early.

Should I fertilize nasturtiums?

Usually not. Nasturtiums grow well in average to lean soil, and extra nitrogen tends to produce leaves at the expense of flowers. A light compost top-dressing in spring is generally enough.

Conclusion

Companion planting with nasturtium works best when you pick the right type, time sowing to match your main crops, and give plants enough space to grow. Monitor them weekly so they can do their trap-cropping job, and leave some blooms open for pollinators. With these steps, nasturtiums can add both function and beauty to your vegetable beds.

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Emily Parker

About Emily Parker

Emily Parker is part of our editorial team and reviews and edits our vegetable & edible gardening guides, checking product details against manufacturer specifications and owner feedback.