Nasturtiums are beautiful flowering plants in outside beds, but in warmer areas those with lots of blooms may become self-seeding. Nasturtiums can continue to grow when removed from your flowerbed if roots are still alive or if seeds drop from flowers.
Controlling Nasturtium Plants
While not too common, if spreading nasturtiums are smothering other flowers in your beds, you can remove and dispose of them or replant into other areas. Planting into a container is a good control measure. That way, you can still enjoy the beautiful blooms.
How to Stop Nasturtium Spread
If you truly want to get rid of all the nasturtiums in your landscape, you can dig them up. Get the entire root ball. Make sure to dispose of them by deep burying or burning. If you can put them in your out-going trash, that is a way to guarantee they will not return. However, you may see them decorating the landfill in years to come. Keep an eye on the area for new plants that may spring from dropped seeds. Pull these up as you see them sprout.
If you just want to limit the nasturtiums that grow, remove seeds before they drop. Seedpods develop as flowers fade. Removing seeds can become a laborious chore. Saving them for an edible use might cause you to be more inclined to keep up with it.
The seedpods are edible, with more of the mustard-like peppery taste. You may pickle them (use in place of capers), along with the blooms for use in salads and as additions to pasta dishes. Of course, you can just put dried seeds into a grinder as a peppery spice when cooking or adding to finished dishes.
You may also save them for planting in other areas where you might want them to grow again. Choose an area where it is acceptable for self-seeding nasturtiums to naturalize. These attract bees and other pollinators while adding beauty where they grow.