Do your cats like catnip? All of ours do but it’s Pixie that is most crazy about it. Arty normally just tries to eat it, Oscar rubs his head on it and falls asleep. Pixie however, goes totally crazy, rolling about, it’s hilarious!
We grow our own and it’s really easy. After the last frosts of winter, when its starting to get warm, just sow catnip seeds in a compost filled pot and leave. You can sow it earlier if you have a cloche to cover it (or cut a pop bottle in half to make a mini-greenhouse over the sown area). Apart from making sure it has enough water you really don’t need to do anything, it’s super easy to grow.
We made our planter out of an old Henry vacuum cleaner. We’ve had to put the mesh around it because the cats kept lying on the plants and squashing the so they wouldn’t grow. Once it gets this big I cut it back the bigger stems to let the smaller ones grow. Drying it is easy. Just put it in a dark cupboard for a week or two, until it’s dry and brittle. Then store it in an airtight container. We had some that was years old and it still worked its magic on the cats so you can store it for a long time.
I sprinkle some of the dried catnip on the floor for them to roll about in. You can also sew some into little fabric pouches, they last for ages and are much less messy.