Garden experts recommend this plant for its natural ability to keep snails out of your flowerbeds
When you are up against garden pests, namely snails and slugs, nasturtium is a useful, eco-friendly option. Known in Germany as Kapuzinerkresse, this bright plant not only helps keep those visitors at bay but also looks attractive and has culinary uses. Here is what makes nasturtium useful against gastropods (snails and slugs).
What makes nasturtium special
Nasturtium is easy on the eye, with striking orange-yellow and red funnel-shaped flowers and round leaves that people often call “little lanterns.” It comes in two distinct forms: climbing varieties (great for trellises) and low-growing ground covers.
Beyond the looks, nasturtium contains mustard-oil glycosides (a bitter compound found in the plant) and gives off a sharp, peppery scent. That combination deters many molluscs; the taste and smell encourage them to move on. At the same time, nasturtium can act as a sacrificial plant, drawing snails away from more delicate crops.
How to grow nasturtium for snail defence
Sow nasturtium seeds outside from mid-May, once the risk of night frosts has passed. Sow them directly into the soil at a depth of 2,3 cm, spacing them 20,25 cm apart. They like sun but will tolerate partial shade, so they are fairly adaptable.
The first leaves appear within 2,3 weeks, with strong growth after that. For snail control, plant nasturtiums in thick lines, dense islands, or a closed ring around vulnerable beds. Make sure the protective belt has no gaps, as snails will exploit any weakness.
Simple maintenance tips
How you water matters. Water nasturtiums in the morning; watering in the evening creates the moist conditions snails favour. Try to keep the nasturtium belt slightly drier than the most vulnerable parts of your plot.
Raised beds help, too: they dry out faster and are less attractive to molluscs. Adding a narrow strip of gravel or crushed stone between the nasturtiums and your main bed gives an extra layer of defence.
Gardeners’ stories and trial notes
Gardeners from different regions report mixed but promising results. A female gardener from the Eifel region had long struggled with slugs despite using beer traps, early-morning wood-collecting sorties, and copper tape, all with little success. After a quiet neighbour, a man of few words but full of wisdom, gave her some nasturtium seeds, she planted them in a semicircle around her vegetable bed and noticed a clear improvement. It did not solve the problem completely, but it protected her crops much better.
A bio-gardener from Lower Bavaria put it well: “Slugs are not enemies you beat once. They are cohabitants with whom you negotiate clear boundaries.” His point is to combine nasturtium with other gentle measures, like hand-picking and sensible garden design, for a workable balance.
More than just a barrier: the extra benefits of nasturtium
Nasturtium is not only for keeping snails away. The leaves, flowers and even green seeds are edible, offering a mustard-like tang. The seeds can be pickled and used like capers. They also attract pollinators, which helps overall garden biodiversity. It therefore provides both a protective function and something useful for the kitchen.
Nasturtium will not solve every snail problem on its own, but used alongside other measures it is a practical and attractive element of garden pest control.