Easy plant question.

Bought a few plants from a lfs. Each plant is planted in a small plastic basket with holes, inside that is a piece of sponge I think. I was suprised when the salesman said don't forget to take the plants out of the basket before you plant them, otherwise you have a problem with them rooting. I thought the idea was to plant them still in the basket. Thanks,

either way. the sponge as you call it is probably rock wool. It offers mechanical support to the plant while it is growing in the nursery, but nothing more.

If you like the appearance of the basket, leave it. Otherwise, remove

Rockwool is that material. I don't think it hurts anything if you leave it in the wool and plant it (which I did when I first bought plants), but it is recommended that you remove the rockwool and then plant in the substrate.

Depending on the plant species, leaving them in the pot might inhibit their proper growth. Some even become root-bound in those baskets and die off.

I also heard that it's best to remove the plants from those plastic baskets, which is not too easy, especially if you don't want to damage the plant. Sometimes, it helps to put an aquarium plant tab under the root.