First thing’s first - what are plant nematodes?
Before getting into the nitty-gritty of this question, know that not all nematodes are pests. In fact, some varieties are beneficial and can be utilised in hydroponic and soil gardens alike.
Nematodes are thin, non-segmented worms, usually less than 2mm long. They’re well adapted to surviving temperature extremes, different soil compositions and moisture levels and their small size makes them tricky to spot and control.
Nematodes feed on plant roots leaving behind galls or knots which look like small, irregular shaped blisters covering the root system of the affected plants. The process of feeding not only inhibits your plant’s ability to uptake nutrients but also leaves open wounds on your plant’s root system. These open wounds make your plants more susceptible to pathogenic fungi and bacteria, and no matter what way you look at it - pathogenic disease is never a good thing.
As always, the best defence is a good offence. As nematodes thrive in organic matter (like soil and compost), switching to a hydroponic grow media like expanded clay will quickly take care of your nematode problem.
If for some reason, you’re unwilling to give hydroponics (or aquaponics) a try, there are a few things you can do to get rid of your nematode problem.
The first option you have is called soil solarisation.
Soil solarisation is an effective and easy way to control nematodes, but it does take some time. Solarisation is just the process of superheating your soil over extended periods until your nematodes die off.
Ideally, you’ll want to carry out this process in summer while it’s hot, although you can also solarise your soil in cooler weather - it’ll just take a little bit longer.
Start by removing all plants/veg from your garden. Next, you’ll need to wet your garden beds thoroughly, checking to make sure the soil is wet all the way down.
Once that’s done, you’ll need to cover your garden bed with a sheet of UV resistant plastic - we recommend panda film, which can be purchased by the metre from our Canning Vale Warehouse.
Your plastic sheeting should cover the whole garden bed and should lay flush with the soil, so you’ll need to remove any retic preventing direct contact.
If you’re carrying out this process in summer, you’ll need to leave everything to sit for four weeks. Otherwise, it’ll need to sit for 6-8 weeks.
Once that’s done, you can re-plant as normal - minus the nasty nematodes.
You can also try planting marigolds as a companion plant as these are natural nematode deterrents, or try adding predatory insects like beneficial nematodes into your garden.
The pest control method you use to rid yourself of nematodes will depend on your setup and goals. For example, suppose your garden is full of beneficial bugs like earthworms. In that case, you might want to use solarisation as a last resort as the process is non-selective and will kill anything and everything living in your garden beds.
And that’s it for today! If you have a nematode problem - hopefully, it won’t be a problem for much longer. If you don’t have a nematode problem, you have all the information you need to deal with them should an infestation ever come your way.
Thanks for reading, and as always, happy growing!