10:21 - 04 March 2011
A garden greenhouse is a protected space, sheltered from the vagaries of the weather and the perfect place for a mouse or rodent to raise its young. The continual supply of tasty green shoots, packets of seed and suitable bedding material are a magnet to these little creatures. Many attempt to move into the greenhouse for the winter, nesting within the shelter and feeding on plants, roots and seeds. Others move in during spring while looking for suitable nesting sites.
First of all rodents are very shy and very scared of people, so regular visits to your greenhouse and daily attention to your greenhouse plants can be enough to scare them off. A daily visit can send them in search of a new home, especially if they have recently moved in.
It’s almost impossible to keep a greenhouse rodent free. The very nature of the purpose of the greenhouse demands good ventilation, opening vents and windows and door access, all of which provide easy access for creatures of all sorts. What’s more all rodents can squeeze through very small holes specially when there is something delightful as a greenhouse home as the reward.
You need to make the greenhouse environment unattractive. One of the easiest ways to do this is to install and electronic ultrasound device that emits high frequency sound waves that only rodents can hear. Some are battery operated but others can be connected to the greenhouse electricity supply. If the device is installed before a pest invasion then it is likely to be sufficient to deter them setting up home in there. If they have already nested then they are less likely to move out and can in fact become used to the noise. Some devices have an alternate setting so that you can vary the sound and pattern from time to time to stop them becoming resistant to a constant droning or pattern. You need to ensure that they can vacate the greenhouse, so leave a vent open from time to time to allow them to escape.
If mice have already invaded your greenhouse space then you need to act fast as they can create havoc and do untold damage. Plants are not the only victims, any fabric can be decimated for bedding, electrical cables are an apparent delicacy and their toilet activity is unpleasant and unhygienic.
However these are sentient creatures so you need to decide how you want to deal with them. Killing them is the last resort and if this is your choice you need to choose a method that is swift and effective. Poisons carry a huge risk if you have pets or children and should be used with great care and respect. Traps are quick, but need regular attention in case they maim rather than kill. The kinder option is to employ a humane trap that is baited with chocolate or peanut butter and catches them in a little vessel. It is vital to check these traps several times a day because if you do catch anything it can suffer a slow, cruel death inside the trap, unless it is released quickly. When you do catch the offending critter, you need to take it a couple of miles away and release it into the wilderness or it will keep coming back and returning to your greenhouse.
Tiny holes in the greenhouse structure or access holes can be filled with wire wool or crushed aluminium foil, rodents don’t like chewing through metal, and so this is good for plugging places where they are getting in.
Mice and rodents are attracted to food sources, so if you store seed packets, chicken food or birdseed in the greenhouse this will be an obvious attraction. Store any edible products in close sealing metal bins and metal boxes that cannot be breached by rodents. By removing the food source you make your greenhouse much less attractive to mice and to rats.