Though small spaces can be challenging and the diversity of wildlife attracted can be more limited than in a larger space, the reward of creating habitat for wildlife even on a small scale is well worth the effort for the touch of nature that it can bring to your doorstep. Butterflies and other pollinators will take advantage of flowering plants that provide them with much-needed nectar and pollen. Birds will feed on insects attracted to these same plants and some, such as robins and house finches, have even been known to nest in potted plants high up on apartment balconies.
There are a few tricks to creating habitat value in a small space. The first is to think in three dimensional terms. Don't be confined by the square footage of your balcony or small garden. Think vertical. The addition of fast-growing vines to take advantage of a barren wall can add valuable shelter and nectar or berries for wildlife. Vines can also add privacy or help to camouflage ugly features you would rather not look at.
Another trick to effective habitat creation in a limited area is to consider your property as an extension of neighbouring habitat. I know of a tiny townhouse garden that regularly attracts the extraordinary pileated woodpecker. On its own, this garden would not be enough to support these colossal birds. But the garden was created to mirror some of the habitat elements of a neighbouring ravine. A single tree combined with a small cedar hedge and a carpet of ferns and other native plants allows the pileated woodpeckers to see it as an extension of their woodland habitat. So look to your surrounding areas. A nearby meadow could spill over into your garden with the addition of a variety of colourful perennials. A woodland could be extended with a potted shrub or small tree. You stand a better chance of attracting those wildlife species that are already in the area by reflecting aspects of the habitat they are currently using.
Diversity is another important element. Try to add the maximum variety that your space allows. By including a variety of plants you will meet the habitat needs of the greatest number of different wildlife species. Think also of the seasons. Most wildlife are active through more than one season. Evergreens are always a great addition, even if potted, because they provide valuable winter shelter and early spring nesting spots.
A lack of traditional garden with its beds of soil does not mean you can't welcome wildlife to your property. A balcony or patio can be transformed through the use of containers.
A little forethought and planning can allow you to provide valuable habitat for wildlife even if your property is space challenged. Your generosity will be rewarded not only because you will have created a beautiful oasis of greenery and flowers but also because a steady stream of wildlife visitors will complete your own private touch of wilderness.