Understanding Nasturtium Companion Planting
Selecting companion plants for your nasturtiums offers a dual advantage: it can boost their growth, enhance flower production, and crucially, help ward off common garden pests. Nasturtiums themselves are known for their ability to act as a 'trap crop' for aphids, drawing them away from more vulnerable plants. By strategically placing certain species nearby, you can amplify these natural defence mechanisms and create a more resilient, productive garden ecosystem.
The principle behind companion planting is simple: different plants can benefit each other through various means. This includes attracting pollinators, repelling harmful insects, improving soil quality, or even providing physical support. For nasturtiums, their vibrant, peppery blooms and broad leaves offer a striking visual appeal, but their true garden value lies in their beneficial interactions with other flora and fauna.
When considering what to plant near nasturtiums, think about what you want to achieve. Are you aiming to deter specific pests like whiteflies or certain beetles? Or perhaps you wish to attract beneficial insects such as ladybirds and hoverflies, which prey on aphids? Understanding these goals helps narrow down the best planting partners.
Consider the needs of the nasturtium itself. They generally prefer well-drained soil and don't require overly rich conditions; in fact, too much nitrogen can lead to lush foliage at the expense of flowers. Companions that have similar or complementary needs will thrive alongside them, creating a balanced planting scheme.
The variety of nasturtiums you choose – trailing or bush types – can also influence companion planting decisions, primarily based on space and growth habit. Trailing varieties might need companions that don't compete for ground cover, while bush types can integrate more readily into mixed beds.
- Nasturtiums deter aphids and attract beneficial insects.
- Companion plants enhance nasturtium growth and pest defence.
- Match companions to desired garden benefits like pest control or pollination.
- Consider soil and light needs for harmonious growth.
- Growth habits of nasturtiums inform companion choice.
Beneficial Neighbours for Your Nasturtiums
Certain plants stand out as particularly effective partners for nasturtiums, contributing to a healthier garden environment. These allies work in concert to create a natural defence system, making your gardening efforts more rewarding.
For direct pest deterrence, **brassicas** (like cabbage, broccoli, and kale) greatly benefit from nasturtiums planted nearby. The nasturtiums act as a sacrificial trap crop for aphids and flea beetles, diverting these pests away from the brassica leaves. This natural tactic can significantly reduce the need for chemical interventions on your vegetables.
Radishes and other root vegetables also pair well. They can help break up the soil, and the nasturtium's presence can deter root maggots, while the radish might help deter cucumber beetles. The combination creates a polyculture that confuses and repels pests that target specific crops.
Herbs frequently make excellent companions. **Rosemary** is known to deter a range of pests, including cabbage moths and bean beetles, and its woody structure offers a different aesthetic and soil profile. **Mint**, while vigorous and best kept in pots to prevent spreading, can repel ants and aphids. **Thyme** is noted for its ability to attract beneficial insects like ladybirds and parasitic wasps, and its low-growing habit complements nasturtiums well.
Among flowers, **marigolds** are a classic choice. Certain varieties, particularly French marigolds, are reputed to deter nematodes in the soil and repel various flying insects. Their bright colours echo the cheerful nature of nasturtiums, creating a visually appealing display. Similarly, **sunflowers** can provide a vertical element and attract pollinators, though they require ample space and can be competitive for nutrients, so placement is key.
Here's a more detailed look at some of the most effective pairings:
Vegetable Allies
- Brassicas (Cabbage, Broccoli, Kale): Nasturtiums draw aphids and flea beetles away.
- Radishes: Help deter root maggots and cucumber beetles.
- Tomatoes: Can benefit from nasturtiums warding off whiteflies and aphids.
Herbaceous Helpers
- Rosemary: Repels cabbage moths and bean beetles.
- Mint: Deters ants and aphids (plant in pots).
- Thyme: Attracts beneficial insects and has a low growth habit.
Floral Friends
- Marigolds: Repel nematodes and flying insects.
- Sunflowers: Attract pollinators, provide height.
- Cosmos: Attract beneficial insects and add delicate colour.
The most successful companion planting schemes often involve diversity, so don't hesitate to experiment within these guidelines.
Plants to Keep Apart from Nasturtiums
While many plants complement nasturtiums, some can hinder their growth or attract unwanted attention. Understanding these incompatibilities is as important as knowing the beneficial pairings.
Generally, avoid planting nasturtiums too close to **beans** (both bush and pole varieties) and **peas**. While nasturtiums can be a sacrifice crop for aphids, they might also attract the very pests that target legumes. Some gardeners find that beans may also stunt the growth of nasturtiums.
Large, competitive plants like **cucurbits** (squash, cucumbers, melons) can also be problematic. Nasturtiums prefer not to be overshadowed or outcompeted for water and nutrients. While nasturtiums might deter cucumber beetles from cucurbits, the cucurbits' size and vigour can dominate the planting space, negatively impacting the nasturtiums.
Another consideration is avoiding dense, overly nitrogen-rich environments. Nasturtiums thrive on lean soil and can become leggy with excessive nitrogen. Companions that require very rich soil or are heavy feeders might create an imbalance that doesn't favour the nasturtium's flowering habit. This is less about direct harm and more about suboptimal growing conditions for the nasturtium.
The key takeaway here is to observe your garden. While general advice is helpful, local conditions, specific pest pressures, and microclimates can influence how plants interact. What works perfectly in one garden might need slight adjustments in another.
Getting the Most from Your Nasturtium Companions
To truly harness the benefits of companion planting with nasturtiums, consider their growth habits and needs, and integrate them thoughtfully into your garden design.
Spacing is critical. Ensure there's adequate airflow and light for all plants involved. Overcrowding can lead to fungal diseases and can negate the pest-repelling benefits as plants become stressed. For bush nasturtiums, interspersing them within beds of vegetables or herbs works well. Trailing varieties can be allowed to spill over edges, with shorter companions planted beneath them, or grown in hanging baskets where their foliage can drape, keeping them away from ground-dwelling pests that might target other plants.
Watering and feeding regimes should ideally be compatible. Nasturtiums do not need frequent feeding; an overly rich diet leads to fewer flowers. Pair them with plants that have similar, moderate needs. If you are planting them near heavy feeders, ensure the nasturtiums are placed where they receive less of the concentrated feed and water.
Crop rotation remains important even with companion planting. Do not plant nasturtiums or their preferred companions in the same spot year after year to prevent soil-borne diseases and nutrient depletion. Instead, rotate them with plants from different families.
Observe and adapt. Companion planting is not an exact science. Keep an eye on your plants; notice which pests appear, which beneficial insects visit, and how vigorously each plant grows. If you see pests on your nasturtiums, reassess the companions or their placement. If a companion seems to be struggling, it might be competing too fiercely with the nasturtium.
Consider seed sowing times. Nasturtiums are typically sown after the last frost. Companion plants like radishes can be sown earlier, and later crops like marigolds or cosmos can follow. Plan your planting calendar to ensure you have beneficial neighbours established when the nasturtiums need them most.
Encourage ladybirds and hoverflies by planting dill, fennel, or yarrow nearby, as these attract the adults whose larvae are voracious aphid predators.
By understanding the synergistic relationships between nasturtiums and their plant neighbours, you can cultivate a more vibrant, healthier, and naturally pest-resistant garden.