Trees or climbing plants that produce wood of a workable quality.

Plants that can be grown for fuel, fiber, resin or other useful products.

Conditions near sea coasts are usually stressful for plants. Only species that are adapted to salt spray, high winds and some drought will do well here.

Plants that produce materials that can be used for decoration, arts and crafts.

Plants with fruits, seeds, leaves, roots, flowers or other parts that are or have been used in one form or another for human consumption or medical treatment. Any dietary or medical information given here should be regarded as anecdotal. Such plants are not necessarily edible and in fact some medicinal and psychoactive plants are highly toxic and can be fatal if ingested even in small quantities. We are listing all of these plants for reference only and do not recommend the consumption of any of them unless you have been able to ascertain their safety through independent research. Under European Union laws, many of these plants would be considered "Novel Food" plants, meaning they cannot be commercially produced for human consumption before going through a lengthy permission process.

Plants that have a moderate or high tolerance to drought situations. This is obviously a wide field that includes plants that tolerate a noticeable seasonal drought period, plants that survive in dry climates with access to underground water and plants that are fully adapted to very low rainfall climates that are dry throughout the year. Even plants that grow in extreme situations (such as on cliffs or trees) in otherwise humid climates may be included here.

Plants can be surprisingly hostile to fend off voracious eaters while others are perfect opportunists. This section describes the ways in which plants may be a hazard to people or the environment.

Judging ornamental value to a large extent is a matter of individual taste, style and preference, and is totally unfair as it has nothing to do with a plant's ecological success. It still is an excellent guideline for how to use a plant in the ornamental garden.

Plants can be classified by their life form or growth form. The Raunkiær system provides an easily accessible approach and is still widely used.

The growth rate of plants is important to know. For instance, in order to judge how quickly a plant will fill a certain space or how quickly a plant will reach a saleable size in a nursery. The size of a plant does not really play a role here, as even a dwarf plant can be fast growing (like many weeds).

Plants that tolerate high winds will naturally also thrive with less wind. If wind is not an important factor at your site, leave this field unchecked.

Particularly important if no irrigation can be provided. If your garden is irrigated or receives enough rainfall, you can leave this field unchecked.

The ability of a plant to survive freezing temperatures depends on many factors. The temperatures indicated here may be sustained by mature, established plants as an occasional, brief event. Many other factors need to be considered though, such as duration of the freeze, sunshine, daytime temperatures, general climate, rainfall and humidity. Also, mature plants are considerably hardier than seedlings and there are differences in hardiness between individual plants.

The light requirements of many plants change as they grow up. They become more light tolerant. Please take into account that full sun in a desert climate is not the same as full sun in the humid tropics, where the humidity is high and it is often cloudy or hazy.