Many trees like these can be grown in a relatively small space. Espaliers have selected vertical branches trained to wires. Both cordons and espaliers take much pruning and work in the early years but are better suited to limited space than other trees and can be maintained at a height close enough to the ground to be cared for by someone in a wheel chair. Annuals are very popular in gardens for many reasons. They are generally easy to grow, fast blooming plants which can provide quick, if only temporary, color to the garden.
Many annuals are shallow rooted, adapting well to the shallow elevated planters.
The wide selection within many varieties provides diverse colors, flower types and sizes from which to choose. An annual can be found to suit almost any garden need, be it a border for a vegetable garden, cut flowers, or a vibrant floral display. Annuals can be used to fill gaps in the blooming sequence of perennial plants and are more desirable in unprotected planters in which perennials could not survive the winter. Some annuals are mistaken as perennials because they can self-seed easily. Set out as bedding plants, annuals provide nearly instant gratification and feelings of pride and success.