It is definitely not fun to see how pests or vermin destroy your crop. But at the same time, it is not fun to feed your plants toxic chemical pesticides that not only hurt rodents or insects but also affect our own health, soil, and groundwater. Fortunately, there is an option that can preserve your garden and the wildlife at the same time, and we are talking about natural ways to protect the crops.
The biggest problem with regular chemical rat poisons is that they kill not only rodents but also lots of other representatives of wildlife. The California Department of Fish and Wildlife (CDFW) reported that only by 2015, rodenticides had injured and killed thousands of foxes, coyotes, mountain lions, raccoons, hawks, owls, and many other wild animals. Moreover, they also affected domestic pets and even children.
Chemical pesticides do not cause immediate death of the animals; after the toxins get inside their body, they endure intense pain for several hours or even get an internal bleed. There is no reason to cause this kind of suffering if you have other ways to save your crop that are more tolerant to the wildlife.
The great thing about wildlife is that they can know about each other's presence even without personal contact. Mice and rats can smell that the garden is “guarded” by other animals, and that will make them leave the dangerous place. And this is what we all need, right?
The easiest way is to get a cat. This purring creature is not only able to catch rodents; it can also leave a special pheromonal aroma that signals to mice about its presence, and therefore, scares away the rodents.
Not all cats like catching mice, some of them prefer sleeping on the cushion all day long and waiting for their master to put food into their bowl. So, if you can choose, pick a “working cat” rather than a long-haired short-legged pedigree animal. Those cats are not always able to live in the house (they hiss, they hide, they ruin the carpets and your shoes), but they are the ones who can master the mice-catching art. Moreover, most shelters can help you with choosing the right cat as they often know pets' specialties: some cats are better at catching mice while others are good at hunting rats.
If getting a cat is not a decision you want to make, you can also invite someone's else pet to visit your garden. As we said before, even the presence of a cat (and mostly the scent of their pee) can scare the vermin away from the territory. Give your neighbor's cat some food, stroke the animal, get it to visit your backyard, and you will see the rodent population declining without you actually doing a thing.
Another way to scare away vermin is to attract wild predators to your territory. You might already know what kinds of animals live in your area, and if there are owls, hedgehogs, snakes, foxes, or bobcats, you can try to invite them to visit your garden once in a while.
Of course, if you grow cannabis in the backyard, bobcats and foxes are not an option. But they can fit your situation if you have a large field of plants. To attract them, leave around some food that these animals might like. It is better to leave it around dusk, as most predators are nocturnal. Of course, there is a risk that rodents will grab that food, too. That is why it is recommended to leave moistened food as mice and rats mostly prefer dry foods such as grains and cereals. Leave it in the same place every evening and do not forget to get rid of all the leftovers in the morning.
Pretty much the same instructions can work for inviting hedgehogs to your place. Not that they hunt mice, but they like to eat slugs that can often damage your crop. Leave them some soft moistened food (you can use usual tinned pet food, just avoid the one that contains fish) and a bowl with fresh water. Do not leave milk for them, hedgehogs are not tolerant to lactose.
To attract owls, you can get special barn owl nesting boxes. The good thing about owls is that they are almost non-territorial, so they will not fight with each other for the right to hunt in your garden, and that means that you can have as many owls as the number of nesting boxes you install.
As an alternative, you can also invite raccoons, opossums, skunks, badgers, and even coyotes and mountain lions. Why not let the animals get their food and help you get rid of the problem at the same time? This is a win-win situation.
Terpenes are the tiny compounds that are responsible for the plants' scents. Cannabis terpenes even have some beneficial properties—they are responsible for the potency of the high, and many of them provide medical effects when the weed is ingested or inhaled.
At the same time, terpenes also can attract or scare away the invaders, including insects and animals. In most cases, the stronger the scent, the less it is attractive to the vermin.
For instance, you can use a citronella plant or spray your garden with citronella oil. Recent studies showed its effectiveness against a number of pests. Moreover, the oil makes male mice seem less attractive to females, which leads to less procreating and fewer baby mice.
Moreover, citronella oil causes some chromosomal abnormalities in mice, which means that if even rodents do have babies, they will be less likely to survive.
If you apply eucalyptus oil to the plants, it will make the plants less attractive to rodents. It is very effective, but unfortunately, it has a temporary effect. You need to apply this oil at least twice a week, otherwise it will not work properly.
You can also plant mint together with cannabis, or any other strong-smelling plant. However, you should remember that they can affect the marijuana smell as well, so it is up to you to decide. We would recommend you to use companion planting /terpene spraying in tandem with other remedies—this way will be the most effective.
Sometimes, using natural predators or companion planting can be difficult, especially if your garden is situated close to the house that is also full of rodents. In this case, you can use other ways of controlling vermin population without applying weapons of mass destruction.
You can get single- and multiple-entrance snap traps, glue traps, or electrocuting traps. You can also use all kinds of DIY traps—just google them, there are a ton. The easiest one includes a big bucket with some water on the bottom (you can also add some liquid soap to accelerate the drowning and make the rodents' death “more humane”) and a rotating can attached to the top of the bucket. To make a spinning wheel out of a can, you need to drill holes in the center of its both ends and put a rod through them. Cover the can with peanut butter so that it attracts rats, install a log or something that would allow animals to get from the ground to the top of the bucket, and gravity will do the rest. A mouse will jump onto the can, it will spin and throw them into the water.
However, be very careful with traps if you have any pets; be sure they do not become the victims of your hunting. And, of course, you should be ready to throw away dead rats and mice.
Traps may not be the most peaceful way to get rid of the vermin, but they are definitely much safer for people, pets, and wildlife than any chemical rodenticides. You should not expect all the rodents to become extinct in one night, but eventually the traps will do their work. After all, your goal is not to destroy the rat population but to keep your crop safe.