How do I cross plants?

you drag the pollen from one on to the other - simple! You must be sure that your soil is good enough though as the resulting plants may not survive.

Of course, you don't get a plant from crossing plants until you plant the resulting seed. So, you can hang on to a seed that wouldn't survive in the current soil until you get the better soil.

Oh.

Um,how do I drag the pollen to one another?

Click on the plant that you want to use to pollinate the other plant. On the left there's a little window with sparkly stuff in it. That's the pollen. Grab that with your cursor and drag it to the plant you want to pollinate.

Oh.I did that!