Beginning gardeners often forget to plan their gardens, and what it might look like when it’s grown. Baby plants are very similar in size, but as adults, they are all very different.
Fundamentals of garden planning say that the taller plants go in the center of a garden (or container) you can walk all around, and the back of a garden against a wall or fence. Of course, all rules are made to be broken, but the taller / shorter planting groups rule is a good one to know so you can break it thoughtfully.
Let’s say you’re planning a yellow garden with sunflowers, snapdragons and marigolds. Since you’ll still want to see the snapdragons and marigolds when everything is mature, plant the sunflowers behind them. One way to break the tall/short rule is to plant two rows in a slim garden between two walkways:
Row 1: sunflowers, snapdragons, marigolds
Row 2: marigolds, snapdragons, sunflowers
This would result in an interesting wave effect from both sides of the garden.
Pick plants that like the same or similar amount of sun vs shade (it’s usually on the tag). But remember that even the most careful planning can end up being a “mistake” – and that’s just a part of the process. I once planted camellias (known shade lovers) in the shade of a neighbor’s tree. They did really well – until the neighbor took the tree down. They had to be moved, but that’s gardening. Plan and adjust. Learn. Repeat. And don’t forget to enjoy!