There will be some symbols that might not have the correct size. For example if I have a plant that says it's 25' in width, but when you drag it to the grid paper it comes out a different size say 50'. The way to correct this is simple. In the content librarian. Find the plant and simply right click on it. Then choose resize symbol. You can change it to the correct size there.
Please know that we are always continuing to improve our plant database.