Allium purple sensation invasion

Asked March 20, 2017, 10:48 PM EDT

I planted THREE allium purple sensation bulbs in my flower garden about ten years ago. Now I have THOUSANDS of them all over my garden, and some of them jumped into the lawn too. I realized that the flowers seeded themselves after four or five years later, but it was too late. Every early spring, I tried to pull them out as many as I can, but the bulbs stayed under ground. More and more come out every year. I am afraid that I might have to turn the garden upside down in order to get rid of the bulbs. The trouble is that I have so many perennials, shrubs and roses in the garden. I would desperately like to know if there are better ways to get rid of them. Thanks. Joy

Jefferson County Colorado flowers: annuals and herbaceous perennials

1 Response

Ah, yes - how allium scan reseed in the garden! Here are some suggestions

  • Dig out the bulb where you can
  • If this is not possible, repeatedly cut off the leaves at ground level: this will prevent the plant from photosynthesizing and eventually the stored energy in the bulb be used up and the plant will die.
  • If the allium is the only monocot (lilies, iris, etc) in your flower garden, you can try a selective herbicide such as one containing 2, 4-D (like Grass be gone). This type of herbicide cannot be used in the lawn, since grasses are also monocots.
  • You can try very focused spot application of Roundup; be sure it is a VERY calm day and make a shield out of a paper plate wrapped around the target plant to avoid overspray (roundup is non-selective and will kill all plants)
  • To prevent future seedlings:
    • Dead-head thoroughly
    • If you are not planting flowers or lawn by seed, apply a pre-emergent herbicide the keep the seeds from germinating.
Here are two fact sheets for more detailed information:
Lawns: http://www.extension.umn.edu/garden/yard-garden/lawns/weed-control-in-lawns/
Landscape Plantings: https://www.uaex.edu/publications/PDF/FSA-6137.pdf

Best regards,