There are potentially many tens of thousands of plants available to select for a garden. Apart from knowing which colour palette, form, structure season of interest is needed from an aesthetic point of view, choosing plants that will thrive in any given set of conditions can be tricky. Below are some key points to consider. Many websites will highlight the individual preferences for a plant.
Spaces available for planting
Before selecting any plant determine the areas available for planting and where tall plants like trees and shrubs can be located. Commercially available plants tend to have guidelines for the potential mature height and spread they are likely to achieve. Selecting plants that will eventually spread beyond the available space will tend to look untidy, compromised and could impact other areas of a garden. Selecting a tree that grows too tall can block light which will affect which plants can be planted nearby.
Soil & moisture
Having plants that are suited to the type of soil in a garden will help them to thrive. Soil can be either alkaline or acidic and its texture can be either loamy, claylike, sandy or chalky. Changing a garden’s soil texture can be done e.g. by improving it with organic matter or by adding grit. Changing acidity or alkalinity can be less successful as the underlying sub soil / sub strata will usually determine the soil’s pH. Plants also like certain soil moisture conditions so for example, plants that like boggy conditions, like certain types of iris, may not thrive in conditions where there is sandy, free draining soil.
Sun & shade
Some plants can be total sun lovers, others can only tolerate permanent shade and yet others will accommodate some sun and some shade during a day. Knowing which parts of a garden are in full sun, partial shade or full shade will help determine which plants will work best in those situations.
A garden’s aspect is important as it can have a big impact on which plants will grow there successfully. So, in the UK,
North facing sites
Exposure and hardiness
An exposed site may experience a number of different conditions e.g. high winds, prolonged sun, heavy rainfall. Some plants cope better than others with this type of exposure and others prefer a much more sheltered set of locations. Hardiness determines how well a plant will be able to cope with cold temperatures. In the northern hemisphere, the further south the location is, generally, the less hardy a plant needs to be although beware locations that may contain potential frost pockets.
Rob Howard, Garden Designer