Absolutely none! Unless you are an expert grower and want to experiment and don’t mind killing your plant, Venus flytraps should never be fertilized. Expert growers sometimes apply extremely diluted fertilizer directly to the leaves of the plant, but using normal fertilizers in the normal way will likely kill the plant.
If you wish to accelerate the growth of your Venus flytrap, it should be fed regularly during the growing season. Be sure to read the article on Feeding your Venus flytrap.
