When choosing the right tree for the right location, the following factors are important:
- Soil type: What kind of soil will the tree be planted in?
- Groundwater level: What are the average high and low groundwater levels?
- Available underground space
- Above-ground dimensions: How wide and tall can and should the tree grow?
- Other site factors such as geographic location, paving, and wind.
- Check the availability of the species.
The designer’s concept and vision are also of decisive importance. The following points play a key role:
- The designer’s vision regarding form, texture, and structure; height and width; color; seasonal effects; atmosphere; and accents;
- The tree’s function: play tree, improving ecology and biodiversity, degree of climate adaptability, cultural history, food forest, etc.
Once the species has been selected, it is advisable to draw the trees into the design at their mature crown diameter. This makes it immediately clear whether there is sufficient space for the species concerned and whether problems may arise in the future through competition with other tree species or with objects such as public lighting or buildings. The available maintenance budget should also certainly not be overlooked when choosing the species. A designer may have in mind, as the desired end image, a tightly clipped avenue of block trees; if the budget for annual pruning is lacking, the intended end image will unfortunately never be achieved. Leaf fall, fruit drop, insect pressure (for example aphids in certain lime species and species that attract wasps), heaving of paving and branch breakage are also management factors that should be carefully taken into account when selecting the species.