Odor repellent (scent repellent) products are an effective way of deterring unwanted pest animals from visiting the garden and causing damage. They either contain ingredients which pest animals find offensive and objectionable, or those that evoke an instinctive reaction of fear in pest animals, because they smell like predators, or the remnants of their work.
Even though humid weather can enhance the scent of these repellents, rain will wash them away! Some products that are sprayed on may require repeated applications, especially after rains, to remain effective.
A more effective way to use scent repellents, both in terms of pest control outcomes and cost, is to deploy them in a way where they’re not affected by rain.
In this article, I’ll explain a very simple way to use animal scent repellent products more effectively, using a basic device that I invented, that you can construct, which allows the scent deterrents to last a lot longer, and to be used at more potent concentrations!
Protecting Scent-Based Pest Repellents from Rain
How do we prevent anything being washed away by rain? We normally use a waterproof cover for the task.
The problem with scent repellents is that they’re usually sprayed over whole plants or trees, which can’t reasonably be protected with a transparent waterproof cover that lets light through. If we use a plastic greenhouse of polytunnel, that would keep pest animals out on its own, and we wouldn’t need to use deterrents!
Perhaps we need to completely rethink how we use scent repellents/deterrents controls for pest animals.
Instead of spraying these products, we could put them into rainproof enclosures, that hold a far greater amount of deterrent than the quantity sprayed over an area.
Rather than covering a whole plants or tree with these scent repellents/deterrents, we could target the critical access points that pest animals need to walk through to get to their meal.
Thinking along these lines, I devised the concept of a home-made scent-repellent rain guard for use against pest animals. In the following section, I’ll explain how to construct one in under five minutes using cheap and recycled materials, and how to set it up for best effect in the garden!
How to Construct an Animal Scent Repellent Rain Guard
To make a scent-repellent rain guard, we’ll need:
- Scent repellent, either commercial or home-made.
- Plastic bottle with lid, such as a soft drink bottle
- Stiff galvanized iron wire, around 1.5-2.0mm thick (15-12 gauge AWG), and 30cm (12″) in length
- Paper towel or piece of cloth
Step 1 – Cut the plastic bottle around 10cm (4″) below the lid using the scissors, to create a bell-shaped container.
Step 2 – Cut a piece of 1.5-2.0mm thick (15-12 gauge AWG) galvanized iron wire to a length of 30cm (12″) using pliers.
Step 3 – Push the wire through the lid of the plastic bottle. If this proves difficult, either start the hole with a pointed object, or cut the end of the wide at an angle and twist it left and right to cut through the lid more easily.
Step 4 – Bend the wire extending from the open end into a narrow hook or “J” shape big enough to hold a folded up paper towel or piece of cloth.
Step 5 – Place a a folded up paper towel or piece of cloth into the hook, and bend the wire in a little, just enough, to hold it securely. This paper towel or cloth piece will be soaked with the animal scent repellent, so the larger it is, the more repellent it will hold.
Step 6 – Bend the top of the wire into a question mark “?” shaped loop for hanging the rain guard up. We bend the wire into this shape so the rain guard sits straight when we hang it up, so it’s more impervious to rain. A simple “U” shape make it sit at an odd angle because the loop will sit to one side of the bottle.
The rain guard should now look like the example pictured below, with a loop at the top to hang it up, and a hook at the bottom to hold the absorbent material which will be saturated with the repellent.
Step 7 – Pull the wire loop at the top so the paper towel or cloth is pulled up into the bell-shaped rain guard. Next, spray or pour the repellent onto the paper towel or cloth till it is soaking wet and completely saturated.
Step 8 – Hang up the scent-repellent rain guard in the garden where it can do its work!
Think about how pest animals will try to get access to the plants or trees that we’re trying to protect. For vegetables growing on a trellis or support, the multiple scent repellent devices can be hung close to flowering/fruiting plants.
Most pest animals that want to get into a tree to eat the fruit or leaves will need to climb the trunk, provided there are no nearby structures that give them easier access into the canopy.
Hanging the scent-repellent device on the trunk with deter them from climbing it.
If pest animals need to climb up a trellis post or other support, hang the scent-repellent device to block their path. They’ll be climbing face-first into a huge amount or the repellent all concentrated in a single point.
How to Increase Effectiveness of Any Pest Controls
The days of using only a single pest control measure in isolation and expecting it to work are long gone. In the agriculture and horticulture industries, the preference is for the a more scientific, and strategic approach, such as integrated pest management (IPM), a systematic pest management strategy that uses a combination of techniques to limit pest populations and the damage they cause.
Don’t be afraid to combine measures, most work better in combination. I came up with this invention on the spur or a moment, using whatever materials I could find laying around, when Australian ring-tailed possums were eating the espaliered fruit trees in a display garden, at a garden nursery where I worked. I hung these devices along the path and on the posts they were climbing to access the trees, and loosely draped netting over the trees themselves. After three weeks, the possums gave up and moved on. After that, I removed the netting, but left the scent-deterrent devices hanging, and sprayed some more of the repellent into them to recharge them. They had worked successfully, there was no more possum damage in that part of the garden in the following years!
Also, don’t be afraid to get creative! Many gardeners have had good success sprinkling blood & bone fertiliser to deter pest animals from their garden. The way it works is simple, it smells like something dead, which elicits fear in many animals, making them think that there is a predator in the area eating other animals. To protect entry points into a garden, some have tried tying stockings or mesh bags filled with blood & bone fertiliser, but the rain eventually washes it all away. Instead, if the mesh bag was tied to the hook on the rain guard, where the paper towel is places, it will work great.
Most scent-repellents are either ammonia-based or plant-based. The commercial ammonia-based deterrents use aluminium ammonium sulfate, while the DIY recipes use ammonium hydroxide (cloudy ammonia). The commercial and home-brew plant based scent repellents use a mix of chilli, garlic and citronella oil. Some gardeners swear by pet hair (from cats or dogs), to try this option, fill a small mesh bag with pet hair and tie it inside the rain guard. It’s important try try different repellents if one isn’t working as well as expected. Try different ones out, then observe what happens!