You should work out the ground division of a garden like making a plan for a room layout. And more for narrow parts of the garden.
You can regard the word "ground division" as a drawing plan. But it can be called a landscape figure because you need to have a 3D image in your head when you divide a ground.
You write down various things on the plan like the information about the neighboring areas, the buildings and topography etc. That means you collect the information about the garden from where you are going to work on.
What you will build now is a garden, but there are a lot of things you should think about before you build a garden.
Firstly, you should be clear about the contact point between the house and the garden. After this you sketch the main thing on the outline, the garden. This is the procedure for this work.
You have to think about the garden from the surroundings and the garden itself when you make the outline of the garden. You can call such an outline "the first cry of the ground".
Exact dimensions and scales are not necessary in a garden outline unlike in a building draft, but you need to give the image by which people can feel the various materials. I think, handwritten drawings have more personal touch and important things can be better mediated than with precise CAD plans.
Some of you may take it for a random drawing, but on a garden craftsman's drawing, you will find various materials, how to work on them, how to place them and so on. The craftsmen imagine a garden in a 3D space, and they add the concept of time (the fourth dimension), so his drawing becomes like a beautiful role picture.
Such drawings are completely different from scribble. Do you understand?