I started a new flower/daylily bed last fall and what I did to plan my layout was to create a table in word with each column being equal to an approved space for a daylily plant and then decided on the number of rows I could accommodate. Then I did a checkerboard pattern, knowing that every other space was going to be open space for the plants to spread. Once I had my layout figured out, I made a table with the heights of the scapes and when they bloomed. From there, I put the tallest in the back and worked forward, being sure to spread out the times of flowering so that there will be constant color throughout the bed.
I then actually pasted a picture of each plant into the box so that I have a working plan of my garden, should I lose tags or markers.
It worked out really well and with the exception of 1 plant, they all fit into the space I had created and planned for.
Hope this helps with your planning.
