Multipet's Catnip Garden 1oz Silver Vine catnip. Silver Vine catnip is a premium blend of North American grown catnip (80%) and (20%) Silver vine which is a plant grows in the mountainous parts of Asia and gives catnip that extra boost. Gently rub or apply the catnip to your cats toys, scratching post of in a small pile and your cat will either experience a stimulated or euphoric experience. Not all cats react to catnip but it is 100% safe and all natural.