The idea of using nature to control pests is not new. I say control and not eliminate because modern ideas of pest control are often more focused on eradication and elimination, rather than control. There’s a big difference between the two mentalities. Removing something entirely from an ecosystem often has unintended negative consequences. Whereas controlling a pest population to make sure it doesn’t grow big enough to damage plants has many benefits, including stronger and more resilient plants.
Using carnivorous plants as part of pest control in your greenhouse or glasshouse is a great idea. Carnivorous plants not only trap and kill insects but they also actively entice and attract pests to them, hopefully sparing your plants from becoming a tasty meal.
There are a some things to remember before introducing carnivorous plants into your integrated pest management plan. Carnivorous plants won’t remove every insect and every pest from your growing environment. You’ll might even still need to use chemicals, although hopefully much less. Carnivorous plants plants also have their own set of unique requirements, and can’t just be treated like the rest of your greenhouse. They’ll need their own water source and their own soil. You will also need to maintain them to get the best out of them. Just like most other plants, you’ll have to remove dead leaves as they are replaced with new leaves and cut off flower spikes to promote continual growth.
Sundews or Drosera, often make great additions to keep insects under control. The two Drosera I recommend are Drosera capensis (Cape Sundew) and Drosera adelae (Lance-Leaved Sundew). They are low maintenance, tolerant of a variety of growing conditions and produce lots of new leaf growth quickly. They also also very efficient at hunting and trapping insects.
You will need to provide them with their own pots of carnivorous plant soil and a tray of distilled or rainwater to sit in. After which, they can safely be placed among your other plants to help control insects. They won’t be able to control molluscs such as snails and slugs. These pests are too big to be captured.
You’ll need a carnivorous plant for each few square meters of growing area. Less is more when it comes to carnivorous plants as pest management. In order to be able to see whether you’re getting success, you’ll need to examine each carnivorous plant for dead insects. A plant which doesn’t have any bugs doesn’t need to be there.
Carnivorous plants don’t need fertilizer, they’ll receive all the nutrients they need from the insects they are removing from your growing area. Carnivorous plants also don’t like being sprayed with pesticide. If you use chemicals as part of your integrated pest management plan you should remove your carnivorous plants before spraying. They can be re-introduced as soon as the spray has settled.