Fertilising your carnivorous plants in autumn is a great way to help next spring get off to a great start and give you plants a helping hand during winter. You’ve probably heard horror stories about never, under any circumstances being able to fertilize carnivorous plants. The trick is to use the right method and in moderation. So here’s what we do in our nursery.
For all of our fertilising we use distilled water. It might seem like over kill, but the reason is pretty simple. We want to start with 0 ppm water. Adding fertiliser to the water will dramatically increase the dissolved solids. Even after mixing our fertiliser we want the TDS to be < 50 ppm.
To every 1L of distilled water we add 4ml of Seasol concentrate. This is about 1/4 strength. We then mix the solution to ensure an even distribution of water and Seasol. We use a spray bottle to apply a misting of fertiliser to Venus Fly-Traps and Pitcher Plants. Don’t deliberately put fertiliser into the pitcher plants. Stop spraying fertiliser when foliage is wet and starting to drip. We don’t want the fertiliser to get into the media. This will just add unnecessary salts. Many carnivorous plant roots don’t take up much of their nutrients through the soil anyway.
Some Sundews can be fertilised too (e.g. D. capensis), but be very careful to only spray the crown of the plant and not the leaves. The fertiliser will interrupt the mucilage (dew) production if it hits leaves. In worst case scenarios, the sundew leaves can even die from being sprayed with fertiliser. It’s not always possible to spray a crown of Drosera, take D. spatulata for example. It doesn’t have a crown suitable for fertilising. In such cases we don’t apply any fertiliser.
Please take warning, don’t over fertilise your plants. There have been countless heartaches caused by getting carried away with fertilisers. They can easily kill your carnivorous plants. Fertilise once and at 1/4 strength using distilled water. Don’t let the fertiliser enter your plant’s pots. Don’t let fertiliser collect in pitfall traps. Don’t fertilise your carnivorous plants over winter.
We can’t speak for any other fertilizer other than Seasol. Fertilisers are not interchangeable. Experiment with caution.You might also like to incorporated autumn fertilising into your overall fertilising programme, where your plants can be treated every 8 weeks from September – April.
If you’re in any doubt you should always err on the side of caution. Either trial your fertiliser on a few plants and monitor long term results or just don’t apply fertiliser.