A good place to start when choosing plants for your garden is to make sure that they like the climate you got in your garden. By doing your research and choosing flowers that du well in your climate and your type of garden you can save a lot of energy by not having to battle the environment.
If you for instance live in a hot and arid part of the world, try going for plants that are adapted to such conditions. You can for instance seek inspiration from classical Mediterranean gardens or the arid-type gardens created by landscapers in places like Arizona and California. Many gardeners in warms areas assume that all tropical plants will like their garden. This is however a misconception, since any tropical flower hailing from the rainforest will have a hard time coping with dry air (often regardless of how much money you spend on lavishing their roots with water) while tropical flowers used to more arid conditions easily succumb to fungal infections or simply rot away when planted in humid parts of the world.
You need to consider at as many factors as possible when choosing plants. You must also decide how much work you wish to put into altering the conditions of your garden. Do the plants yoo want need a different soil, e.g. by adjusting its nutritional content or tampering with how fast it drains? Do you want high trees that provide shade to the garden? How much time and money are you willing to spend on watering your garden? Do you wish to keep plants that require a greenhouse?
One of the main advantages of having a “natural garden”, i.e a garden based around plants that actually likes the prevailing conditions, is that you will have more time left to spend on a few darling plants that may not be as though as the others. By choosing hardy plants for the base of your garden you can spend more time on a few special projects e.g. a wetland plant that needs a lot of extra watering or a delicate flower that require constant protection against parasites.
One way of going about when choosing garden plants it to visit gardens in your local area and talk to the gardeners. Which plants need constant tending to survive and which ones love the conditions so much they are almost turning into weeds? What is the ground conditions where they will grow? Do they prefer sun or shadow? You can normally get a wealth of information by chatting with local garden keepers; gardeners who are familiar with local conditions and know what will work in the long run.
Another way of choosing garden plants it to be inspired by other parts of the world with a similar climate and soil conditions. Certain areas of New Zeelann and Australia does as an example have conditions very similar to those of the mediterranean, plants from Himalaya is often suitable for gardens in Canada and Scandinavia. Make sure you don’t use plants that are consider invasive species. Make sure you don’t import plants illegally.