3.2.11

Those #**# Snails !!






At some point in every gardener's life in the subtropics, you'll run into snail problems. It can happen at any time of year, but is especially prevalent in the warmer months of high humidity and rain. Snails can be devastating to many types of plants, and at the least, they can annihilate flowers and seedlings in short order, disfiguring a plant beyond sale-ability or show-ability. Why, if snails are prevalent in Summer, would I write a blog in January ?

Prepare yourself NOW for Summer's damages. This is the time to seek out where snails hide, remove their food sources, take preventative actions, and start a holistic program of control before the problems begin. Now is an excellent time to clean up stacks of pots, remove piles of rotting leaves under benches, kill weeds, and lift bags of mulch or soil off the ground onto pallets or racks. There are books written listing hundreds of methods of snail control, many of them by British authors. It must be enough of a problem in the UK to write an entire book about snail and slug control........... 

There are many tactical methods used to control snails, some of which are organic, some are chemical, both are equally in different ways. Aside from following basic hygiene protocols involving a clean up of debris, lumber, and old pots in the areas where snails may be prevalent, considering how much time you have to spend on snail control will drive the decision on which control measures to employ. Some of the most Earth-friendly fixes are the most time-consuming.

Cuban Land Snail
                                                                                                                                                                              













There are numerous varieties of plant-eating snails, the term includes slugs as well. Many of these mollusks do their work at night, out of sight of predators, so looking for them in the daylight hours is fruitless. Some snails do their damage  below ground, eating just root tips, especially in container plants. Some of the most damaging snails are quite small. Bush snails can be as small as peas, but they have a voracious appetite. Some of our recently introduced snails, such as Cuban Land Snail, move fast by snail standards, and can strip small seedlings and flower buds in a hurry on hot summer nights. The telltale damage of ragged-edge holes in leaves and flower buds, especially leaf edges, means that you have trouble and need to employ control measures fast. 


There are numerous controls, but the most effective short term controls involve setting out snail baits. There are some which contain metaldehyde, an effective but toxic ingredient. In controlled areas such as greenhouses and in gardens without pets or children, such baits are effective, but should be used judiciously. On of the more popular baits is a blue pellet, and you'll only need a few pellets per plant every month to do the job. Some of the less toxic products contain iron phosphate, and work well, but these products take longer, and need to be used longer to enact good control. Some of the more holistic controls call for setting out dishes of beer, then cover the dishes with a plate or cover to keep rain out. It is the yeast  which does the job in killing the snails, not the alcohol.




A trap for snails, using beer as bait 
cheap beer actually works better than premium brands





















Surrounding a garden with a raised copper band as a lawn edge controls snails quite well, although the copper band needs to be cleaned every few months to expose the copper to the snails. Copper is lethal to mollusks. Some gardeners have spread out pool filter powder composed of diatomaceous earth. This is extremely effective and totally organic, but needs to be re-applied every week or two. Over the course of several months, you'll see the snail problems disappear. The powder is very finely ground silica, and abrades the snails and slugs to death. This tactic is also effective in controlling roaches and other nuisance pests in the lower edges of cupboards and cabinets. Be aware that this powder is irritating to human and pet noses and throats, so be careful in using in children or pert areas.


My suggestion is to employ several measures to control snails and slugs, starting with good garden hygiene and keeping clean pots in stacks off the ground. Start early in the year by using some gentle prevention and control measures to keep snails and slugs away from your valuable plants. Be diligent in watching for damage, followed by rapid response in controlling the problem.These pests are one of the most damaging of all in a garden, and you need to be watchful in order to control them

Craig Morell
Pinecrest Gardens



        

2 comments:

  1. Great suggestions. In addition, last season I used Slug Shields and they worked well. I put them on and didn't have to worry about slugs for the rest of the season. They are also totally eco-friendly.

    Sluggo and other Iron Phosphate pellets contain EDTA which is very toxic. Check it out: http://www.hostalibrary.org/firstlook/RRIronPhosphate.htm

    Good luck.

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  2. Good morning Anonymous- glad to hear that you success with a passive control. I think snails are like squirrels: you need several methods to control them effectively, not all of which need to be active controls. I was not aware that EDTA is toxic, since it is often used in iron fertilizers as a chelating agent. I'll check out the reference, and thanks for the comment.

    Craig Morell

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