Finally, A Slug-Killing Hosta!

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At the Vietnamese Hosta Society annual symposium held last week in Ho Chi Minh City, hosta hybridizer Ngày Nói Dối launched a new hosta that will attract and kill slugs. ‘Slug No More’ is the cultivar name of this plant now in pre-release. It will attract slugs and garden snails from up to 100 m from the host plant, but when gastropods try to eat the leaves, they’re quickly killed. 

Hybridization Complications 

This nearly 25-year quest began with Nói Dối, a research chemist by formation, seeking the chemical substance that caused certain hostas to be so attractive to slugs. From the hostas ‘Undulata’ and ‘Undulata Albomarginata’, she was able to isolate limaxamine, a chemical that slugs and garden snails simply can’t resist. Through careful crossing, she was able to boost the percentage of limaxamine up to five times the normal amount in test plants. Unfortunately, the plants were immediately destroyed by slugs when planted outdoors and could only be maintained under laboratory conditions.

Testing for slug toxicity. Photo agroingeniero.blogspot.com/

She then looked at slug-resistant hostas and discovered that some contained a chemical poisonous to slugs, a glycoside saponin she has called limotoxin C, first isolated from the Hosta ‘Invincible’. Augmenting this chemical through hybridization proved to be more difficult and it took nearly 15 years of crossing to create hosta cultivars with a sufficient amount to limotoxin C to be fatal to slugs. 

That done, she crossed the two lines, finally developing ‘Slug No More’ in 2014. The cultivar has proved amenable to tissue culture and limited distribution is under way.

More about ‘Slug No More’

The new hosta ‘Slug No More’ is a thin-leaved, medium green hosta about 18 inches (45 cm) in diameter and 14 inches (35 cm) in height bearing pale lavender flowers in mid-summer. 

Slugs crawl away from the ‘Slug No More’ hosta and die nearby. Photo: http://www.jaederfeldt.com.

It attracts slugs from long distances, up to 100 m under certain conditions. They bite into a leaf, then crawl a short distance away, dying within 50 minutes. Often hundreds of dead slugs will be found near a single plant recently planted out, but these are soon cleaned up by animals such as carab beetles, toads and birds. Slug predators seem unharmed by the dead slugs and baby Japanese robins and ground beetles fed exclusively on hosta-killed slugs grew to maturity without difficulty.

Slug populations near the ‘Slug No More’ hosta are usually eliminated within two weeks of planting out, allowing gardeners to grow slug-sensitive plants such as lettuce, strawberries, cabbages and other hostas without problems, although there is sometimes a resurgence towards the end of the summer during rainy years, resurgence quickly controlled when the new slugs begin to eat ‘Slug No More’ hosta leaves.

It may be necessary to plant more than one ‘Slug No More’ hosta in areas where slugs are particularly numerous or the plant may be killed. Photo: John Zvirovski, http://www.jamestownsun.com

‘Slug No More’ hosta requires typical hosta culture, growing most vigorously in partial shade, but tolerant of deep shade, even full sun in cool summer areas. It prefers fairly moist soil and may need irrigation in dry climates. It will grow in USDA hardiness zones 3 to 8, although it can also be grown as an annual in tropical climates.

Safety Concerns

This hosta is not poisonous to humans, but the bitter taste of the limotoxin C it contains means it is not considered edible either. Like all hostas, it is slightly poisonous to pets, but the bitter taste of this cultivar is expected to dissuade them from eating the leaves. It is likewise proving to be resistant to deer and rabbit damage. Preliminary studies show they start to nibble on the plant, then quickly learn to avoid it. 


‘Slug No More’, the hosta that will make growing hostas possible again, even in rainy climates. 

A limited number of ‘Slug No More’ hostas will be available this year from April Fool’s Nursery.

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Slug-free Hostas

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With its thick blue leaves, Hosta ‘Hadspen Blue’ is doubly protected against slugs. Photo: http://www.perennialresource

Last year I published a list of hostas that are resistant to slugs. I’ll be the first to admit it’s not a complete list, but it does cover a lot of ground.

However, a list of slug-free hostas won’t be of much use to you if you’re in a nursery looking for some new hostas for your garden and you don’t have a tablet or smartphone to consult. Fortunately, you can do a pretty good job of picking out slug-resistant hostas just by their look and feel.

The first thing to understand is that slugs don’t like hostas with thick leaves. So, just by touching the leaf of a hosta in a nursery, you can usually judge quite accurately whether or not it will attract or repulse slugs. Of course, that won’t be of much use to you if you’ve never handled a hosta before: you do need a certain amount of hosta experience to judge whether a leaf is thick or thin.

Fortunately there another easy method: look for “bloom”. By bloom, I don’t mean flowers, but rather the thin waxy coating that covers the leaves of some hostas and gives them a bluish appearance. Bloom also repels slugs. I don’t know why, but they simply won’t eat blue hostas. In the case of green or yellow or variegated hostas, some are slug-resistant, some are not, but a hosta with blue leaves is always a safe purchase: they are all slug-resistant!

If you want to be a laidback gardener, toss all hostas in your garden that are subject to slug damage and replace them with varieties that aren’t. Not only will your hostas look better, but you’ll reduce the general slug population, thus protecting other plants in your garden from their ravages.

Slug Resistant Hostas: Take Your Pick!

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Abiqua Drinking Gourd

The thick, leathery leaves of Hosta ‘Abiqua Drinking Gourd’ turn slugs and snails totally off!

I’ve had a few requests to publish a list of hostas that are slug- and snail-resistant. The problem is that there are literally hundreds of them! I simply put together a list of the more popular varieties. The next time you go to a garden center, why not bring the list with you? It will make your hosta-shopping so much easier!

Note that all cultivars listed are hardy to zone 3 .

  1. Hosta ‘Abiqua Drinking Gourd’
  2. Hosta ‘All that Jazz’
  3. Hosta ‘Aspen Gold’
  4. Hosta ‘August Moon’

    august moon

    Hosta ‘August Moon’

  5. Hosta ‘Aurora Borealis’
  6. Hosta ‘Big Daddy’
  7. Hosta ‘Big Foot’
  8. Hosta ‘Big Mama’
  9. Hosta ‘Black Hills’
  10. Hosta ‘Blue Angel’
  11. Hosta ‘Blue Arrow’
  12. Hosta ‘Blue Danube’
  13. Hosta ‘Blue Diamond’
  14. Hosta ‘Blue Dimples’
  15. Hosta ‘Blue Ice’
  16. Hosta ‘Blue Ivory’
  17. Hosta ‘Blue Mammoth’
  18. Hosta ‘Blue Moon’
  19. Hosta ‘Blue Mouse Ears’

    Blue Mouse Ears

    Leaf size is not a factor: ‘Blue Mouse Ears’, a very small hosta, is very slug resistance.

  20. Hosta ‘Blue Shadow’
  21. Hosta ‘Blue Umbrellas’
  22. Hosta ‘Blue Wedgwood’
  23. Hosta ‘Bold Ruffles’
  24. Hosta ‘Bright Glow’
  25. Hosta ‘Bright Lights’
  26. Hosta ‘Brother Ronald’
  27. Hosta ‘Brother Stefan’
  28. Hosta ‘Bunchoko’
  29. Hosta ‘Canadian Shield’
  30. Hosta ‘Camelot’
  31. Hosta ‘Capitan Kirk’
  32. Hosta ‘Coast to Coast’
  33. Hosta ‘Curly Fries’
  34. Hosta ‘Devon Green’
  35. Hosta ‘Dick Ward’
  36. Hosta Dorset Blue’
  37. Hosta ‘Dream Queen’
  38. Hosta ‘Fragrant Bouquet’

    Fragrant Bouquet

    Hosta ‘Fragrant Bouquet’

  39. Hosta ‘Frances Williams’
  40. Hosta ‘Garden Treasure’
  41. Hosta ‘Golden Needles’
  42. Hosta ‘Golden Teacup’
  43. Hosta ‘Gold Edger’
  44. Hosta ‘Grand Master’
  45. Hosta ‘Gray Cole’
  46. Hosta ‘Great Arrival’
  47. Hosta ‘Great Expectations’

    Hosta ‘Great Expectations’

    Hosta ‘Great Expectations’

  48. Hosta ‘Green Fountains’
  49. Hosta ‘Hadspen Blue’
  50. Hosta ‘Halcyon’
  51. Hosta ‘Hudson Bay’
  52. Hosta ‘Indigo’
  53. Hosta ‘Inniswood’
  54. Hosta ‘Invincible’
  55. Hosta ‘Jack of Diamonds’
  56. Hosta ‘Janet’
  57. Hosta ‘June’
  58. Hosta ‘Just So’
  59. Hosta ‘King Tut’
  60. Hosta ‘Krossa Regal’

    Hosta ‘Krossa Regal’

    Hosta ‘Krossa Regal’

  61. Hosta ‘Leather Sheen’
  62. Hosta ‘Lothar the Great’
  63. Hosta ‘Love Pat’
  64. Hosta ‘Lucy Vitols’
  65. Hosta ‘Maruba Iwa’
  66. Hosta ‘Metallic Sheen’
  67. Hosta ‘Midas Touch’
  68. Hosta ‘Midwest Magic’
  69. Hosta ‘Mildred Seaver’
  70. Hosta ‘Millies Memoirs’
  71. Hosta ‘Moonlight Sonata’
  72. Hosta ‘Northern Exposure’

    Hosta-Northern-Exposure

    Hosta ‘Northern Exposure’

  73. Hosta ‘One Man’s Treasure’
  74. Hosta ‘Osprey’
  75. Hosta ‘Pineapple Poll’
  76. Hosta ‘Pizzazz’
  77. Hosta ‘Rainforest Sunrise’
  78. Hosta ‘Reflections’
  79. Hosta ‘Regal Splendor’
  80. Hosta ‘Reversed’
  81. Hosta ‘Rising Sun’
  82. Hosta ‘Sagae’

    Hosta ‘Sagae’

    Hosta ‘Sagae’

  83. Hosta ‘Sea Dream’
  84. Hosta ‘Sea Hero’
  85. Hosta ‘Sea Lotus Leaf’
  86. Hosta ‘Sea Sapphire’
  87. Hosta ‘September Sun’
  88. Hosta sieboldiana’
  89. Hosta sieboldiana elegans
  90. Hosta ‘Silver Bowl’
  91. Hosta ‘Sleeping Beauty’
  92. Hosta ‘Snow Cap’
  93. Hosta ‘Sparkler’
  94. Hosta ‘Spilt Milk’

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    Hosta ‘Spilt Milk’

  95. Hosta ‘Stepping Out’
  96. Hosta ‘Sultana’
  97. Hosta ‘Sum and Substance’
  98. Hosta tokudama
  99. Hosta tokudama ‘Aureonebulosa’
  100. Hosta tokudama ‘Flavocircinalis’
  101. Hosta ‘Victory’
  102. Hosta ‘Zounds’