The psilocybe cubensis B+ magic mushroom is a very-easy-to-cultivate strain. Ideal growing circumstances are best if you want to create really large mushrooms, especially a substrate that is rich of nutrients is important here. A really big caramel colored cap will be formed then. The B+ magic mushroom will also grow quite well under mediocre conditions.

When first introduced, many mycologists thought the B+ mushroom to actually be a completely different species: Psilocybe azurescens. This happens to be the granddaddy of all naturally occurring mushrooms from the Pacific Northwestern USA.
The B+ strain has since been correctly reclassified as Psilocybe cubensis.

Although the B+ magic mushroom is not a super fast colonizer, its speed is average, producing some very large mushrooms that are generally a caramel color.

Amongst psychonauts these shrooms generate almost always positive feedback. Experienced shroomers consider the B+ strain a "stock" cubensis: one that is great for all situations and occasions.

Advice is not to eat too many until you have an idea how they effect your mind and bodily experience.