Slugs and snails are a hosta grower’s nemesis as they love to eat their succulent leaves and leave their characteristic shredded holes as they munch away at night.
I personally have tried all the common suggestions such as copper strips, coffee grounds and everything else in between to keep slugs out of my potted hostas but none of these strategies actually work.
That is until I tried the following tips all in concjunction with one another….
- Make a line of Vaseline around the circumference of the pot (or on raised feet underneath the pot) and rub salt into it. The vaseline keeps the salt in place and helps to protect it from dissolving. Slugs and snails will not cross a line of salt, and your hostas will be kept safe.
- Plant slug resistant hosta varieties such as ‘Sum and Substance’ that have thicker leaves which slugs and snails have difficulty eating.
- Always water hostas in the morning to let the sides of the pot and surrounding area dry before nightfall when slugs are active as the moist conditions only encourage slugs and snails.
These three steps implemented together provide a remarkably effective strategy to keep slugs out of pots and away from hostas which has worked better then any other solutions I have every tried.
Scroll down for exactly how to implement these tips and for more best practices (that do not harm wildlife) to keep slugs and snails away from your hostas in pots…
Keep Slugs and Snails out of Hosta Pots with Salt and Vaseline
This is the most effective technique I have ever seen for preventing slugs and snails from devouring succulent hosta leaves.
Slugs and snails will not move across salt (as this will dehydrate and potentially kill them) or dry wood ash. However wood ash is no longer effective after rainfall and is easily blown away in winds, so it is not a long term deterrent.
Salt also will dissolve in water which would seeming rule it out as a long term slug repellent when outdoors.
Here’s the cool trick…What you can do is smear a ring of Vaseline (about half an inch wide) on the outside of the pot ideally at the top as this is most likely to be in the rain shadow.
Then what you need to do is rub the salt into the Vaseline around the outside circumference of the pot. The Vaseline will hold the salt in place and stop it from washing away in the rain.
This will form an impenetrable barrier for the slugs which may crawl up the pot but once they detect the salt, held in place by the Vaseline, they will not cross the line and crawl back down the pot thus preventing a mid night attack on your potted hostas.
I have found this simple tactic to be incredibly effective way to combat the number one problems that gardeners face when growing hostas.
It should be noted that you will have to maintain the salt and Vaseline barrier every now and then as the effects of rain, ice, snow and moisture in the air will gradually dissolve some of the salt and compromise the slug barrier.
However as long as the line of Vaseline and salt is in the rain shadow of the pot then this tactic can work for many months before having to make adjustments.
Alternatively if you have a rectangular or square pot that does not have a rain shadow, then you can raise the pot off the ground on ‘feet’ or stones and form the Vaseline and salt barrier around the feet. With the feet being underneath the pot they can be protected form rain so that the salt remains undissolved and an effective slug repellent for longer.
The advantages of using salt over pellets or other slug repellents or traps:
- The salt and Vaseline method is very discreet in terms of appearances. You cannot see the barrier unless you get up very close to the pot, therefore it will not detract from the look of the luxuriant, ornamental hosta leaves. Slug pellets or other methods such as beer traps are much more obvious and unsightly.
- Salt will cause slugs to become dehydrated, (via osmosis) if it is sprinkled on their bodies. However if it is arranged with the Vaseline around the outside of the pot a slug will detect the salt and retreat unaffected. Slug and snails that fall victim to pellets however, will decease and pass the chemicals up the food chain to birds, raccoons, hedgehogs and any other natural garden slug predator which ultimately has a negative multiplier affect on the ecology of the garden.
- Salt and Vaseline are relatively cheap, the technique is easy to implement and there are no negative affects to wildlife.
Slug Resistant Hostas for Pots
The second tip is great to use in conjunction with salt around the pot is to plant exclusively ‘slug resistant hostas’. No hosta is fully slug and snail proof but there are varieties that are far less susceptible to mollusc attack.
The most popular and widely available of such hostas are ‘sum and substance’ and ‘halcyon’ which are very hardy and fairly large hostas with attractive foliage. ‘Sum and substance’ is credited with being the most slug resistant hosta of all.
Hosta ‘Krossa Regal‘ is comparatively a more modest size hosta reaching 24 inches tall and 24 inches wide at full maturity. This cultivar has thicker, waxy leaves which contributes to its resistance to slugs.
These hostas resist slugs better then others is because the leaves are thicker, waxier and more robust so they are difficult for slugs and snails to eat.
Slug and snail resistant hostas are another great preventative measure that will decrease the chances of slug and snail prevention.
Water Hostas in the Morning (Not in the Evening)
This is one of the easiest tips to implement yet it makes a significant difference. Hostas like their soil to be kept moist, so you have to water potted hostas particularity frequently to keep them happy as pots can dry out quicker then if the hostas were planted in the ground.
A lot of gardeners tend to water plants in the evening which leaves the hostas, soil and ground wet for the coming evening.
Slugs and snails favourite time to emerge is at night and they are most active in moist conditions, increasing the likelihood they will go straight for your hostas and leave their tell tale holes in the leaves.
Always water hostas in the morning as this will charge them with water for the day ahead and it will give the ground and area around your pot to dry out somewhat before night. In conjunction with the other solutions this will make your hostas less of a target for slugs and snails.
More Best Practices
Some other best practices to prevent slug and snail predation on potted hostas:
- Do not leave areas of long grass around your garden. Slugs love to hide in long grass during the day as it retains moisture and shelter thus providing their ideal conditions. Cut your grass once per week and ideally make sure that you strim around the edges and borders of the lawn which is a frequent hiding place. The less potential habitat for slugs around your garden the better.
- Tidy up dead leaves in and around pots. Slugs natural role is to consume decaying organic matter, leaves and dead wood in particular. In the fall make sure that dead leaves to not accumulate for long periods of time in corners of the garden and therefore provide other sources of food or shelter that encourage a slug and snail population.
- Encourage natural slug predators. Birds, hedgehogs, raccoons, badgers, frogs and many other animals will readily control slug numbers. Birds in particular are very effectively slug predators. It is very easy to find a space for a bird box in most gardens and you will be doing your bit for wildlife conservation at the same time!
- Make sure hostas are healthy. Hostas are at there most resilient when they are cared for. So make sure they are planted in a good quality potting mix and keep the soil relatively moist on hot days. Hostas that receive too high a dose of fertilizer will wilt and grow soft and sappy which is ideal for slugs so make sure that you follow the fertilizer manufacturers instructions as more fertilizer is not better.
- To effectively prevent slugs and snails eating hostas requires several steps all implemented in conjunction.
- The most effective strategy is to make a line of Vaseline around the circumference of the pot and rub salt into it so that it stays in place.
- Slugs will not move over the salted barrier. The barrier is best placed out of the rain shadow: either around the top of the pot or at the bottom on raised feet to stop the salt from dissolving. This stategy can be effective for months before you need to add more salt or Vaseline and doesn’t harm wildlife like slug pellets do.
- Slug and snail resistant hostas such as ‘Sum and Substance’ are less likely to fall victim to slugs due to their thicker leaves.
- Water hostas in pots in the morning to allow the pot and the ground around to dry off before night when slugs emerge.
- Clear dead leaves away, mow the lawn regularly to limit potential slug and snail habitat.