Garden Notes

Hosta plants thriving in shaded area of perennial garden

We have a large perennial garden, some of which is quite shady. In those areas, I have spring flowers such as bleeding heart, Virginia Bluebells and Lungwort. When they have finished blooming, a variety of hosta plants replace them and hide the foliage as they fade.

The problem is that while the hosta are very attractive and thrive in the shaded areas, they are slug magnets and by the month of July, if I do nothing, they look ragged and shopworn. I have tried various solutions.

Beer trap — basically placing a small dish or empty tuna can filled with beer into the garden close to the plant being eaten. The container should be sunk into the ground somewhat so the slug does not have to climb very high to enter beer heaven and drown. This works, but you need to keep emptying the traps because the dead slugs get all slimy and stinky in hot weather.

Slug bait — a commercial product that get sprinkled around the plant being eaten. The slugs eat the bait instead of your plants and die. This works but needs to be reapplied after rain, is expensive and can be toxic to animals.

The Board Method — small boards are placed on the damp ground near plants being eaten. In the morning, the boards are lifted up and any slugs that have gathered need to be squashed. This works very well, but is yucky to do.

Ammonia Slug Treatment — This one is new for me. It is a method suggested by Monches Farm, a nursery/gift shop that carries an extensive collection of interesting plants and is located in the Kettle Moraine area of Wisconsin. Their slug treatment is as follows:

1. Mix a solution of 20% household ammonia (1 part ammonia to 4 parts water).
2. Then, using a watering can, apply this solution generously as a soil soak around the crown of your Hosta plants just as the pips are emerging in the spring. This solution should kill overwintering slugs and slug eggs in the soil and significantly reduce your slug population.
3. If slugs continue to be a problem, this solution can be reapplied several times throughout the growing season. Some Hosta fanciers actually spray their Hosta gardens with a very diluted Ammonia solution (1:8) as frequently as once a month.

This year I decided to experiment with the Ammonia Slug Treatment on a few plants in my hosta garden. I want to make sure that the ammonia only kills slugs, not slugs and plants! If this solution doesn’t work, I can always try one last method.

Only buy plants that are slug resistant!