This page explains the design of our Tree Selection Wizard and provides user support
How the Tree Selection Wizard works
TreeBook is underpinned by a comprehensive data base of Southern African trees. Our focus is on data that may be useful to persons planning to plant trees. We organised the data base with reference to key tree features which we think are of interest to our users. These features can be filtered with user defined inputs.
The number of trees that meet users' inputs reduce with every additional filter request. It may soon lead to a situation where no tree exists in our data base that meets all requirements. The user must now compromise.
You may reset all filers at any time. Unfortunately it is not possible to reset only one filter.
Note the buttons on the header menu: "Tree Wizard" and "Tree List Wizard". The Tree Wizard page loads a batch of tree images and a lot of accompanying information. Loading time of this page may be several seconds. The Tree List Wizard page loads a batch of trees in list form only, indexed by scientific name, English name, Afrikaans name and a "detail" button. If you click on the button a new page will open with the tree's image and information. The two wizard pages offer exactly the same choice boxes. We included the Tree List Wizard to reduce loading time and facilitate screen printing of the final list of trees that meet your needs.
User support
Constraint: Minimum Winter Temperature
This filter selects trees from our our data base that will withstand the minimum temperature it is likely to experience in the location where you plan to plant it. It is a very important criterion for the simple reason that if you plant a tree that is not able to withstand this minimum temperature, it will either die completely or re-grow from ground level after every cold winter, thus never growing to its full potential.
You can select three temperature regimes: Trees which will survive a minimum temperature as low as -6 degrees Celsius, those that will survive -2 degrees and those which will survive only light frost around 0 degrees, for example not lower than -0.5 C. If you select "not lower than -2 C", the wizard will also list trees capable of withstanding -6 degrees Celsius. Should you not select any minimum temperature criterion, all trees in the database are available for subsequent refined filtering.
Constraint: Garden size
When a tree's roots have free reign, as it has when you plant it in your garden, it will continue to grow to its mature size. In the process it will spread its roots, lifting nearby pavement or even the foundation of a boundary wall. It may grow over the roof, dropping leaves in gutters, or cast shade where you don't want it. It may extend over the garden fence and become a nuisance to your neigbour. Clearly it is important to consider the size of your garden when deciding which tree to plant.
TreeBook offers four garden size choices. View "garden size" as available area where you intend to plant the tree(s):
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Very small garden. For example a townhouse. The garden is about 25 square meter
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Small garden. For example a regular city erf. Garden size is about 100 square meter
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Large garden. For example a large city erf Garden size is about 1000 square meter
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Very large garden, about 4000 square meter. Garden size is therefor not a consideration
When you select "very small garden", the Wizard lists trees suitable for planting in a space of about 20 square meter in the open ground - that is NOT in a planter or large pot. Only a limited number of trees overcome this constraint. Fortunately there is a solution! Plant trees that do not mind their roots being contained, in a large planter or pot. Reset the Garden size filter. Then set the "choose pot planting" filter to "yes" to find trees that do well in a pot.
Constraint: Clay soil
This filter finds trees which will grow in severe water-logged soil (or clay soil). Only a few species can handle this condition, so use it only when your soil is really water-logged. You can test for severe clay by digging a whole about 30x30x50cm deep and fill it completely with water. Measure the time it takes for the water to drain. Any time above 12 hours indicates severe clay.
Requirements: Leaf growth
Select one from either "evergreen", "semi-deciduous", or "deciduous". Many trees' leaf growth depends on climatic conditions. When it is favorable it may be evergreen, whereas the same species may be semi-deciduous or even deciduous when it is not. This is the reason why some tree books list such species as "evergreen to semi-deciduous". TreeBook decided to make a call on leaf growth and indexed species on their most likely leaf growth cycle. We argued that the wizard will guide you to only plant trees that fit your local climate (temperature, soil, water, etc). Making a call on leaf growth is therefore quite reasonable.
If you make no selection the wizard assumes that leaf growth is not important. It will display all leaf growth forms.
Requirements: Growth rate
You have the following choices for growth rate:
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Very fast. (Infant growth rate more than 1.3m/year)
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Fast. (Infant growth rate about 1m/year)
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Average. (Infant growth rate about 0.6m/year)
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Slow. (Infant growth rate about 0.3m/year)
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Very Slow. (Infant growth rate less than 0.1m/year)
We gave quantitative values to initial growth rates assuming that the tree is fit for your local climate, was properly planted, has adapted to its new environment and is well cared for.
If you make no choice the wizard assumes that growth rate is not important. It will then display all growth rates.
Requirements: Roots
Select one of either "non-aggressive", "slightly aggressive" or "very aggressive". TreeBook was conservative in its non-aggressive classification. As a general (not absolute!) rule, trees with a "small" mature size have non-aggressive roots. The larger a tree's mature size, the more roots it needs to anchor itself. All trees rely on side roots to do this. The idea that a tree with a taproot will not have side roots is a myth.
You may find it strange why anyone would want to find a tree species with "very aggressive" roots? Not so far-fetched - the root system of such a species often extends above ground and is a feature in own right.
If you make no selection the wizard assumes that the tree's root system is not a consideration. It proceeds to display all root forms.
Requirements: Container/Pot Planting
This user input box allows you to select all tree species that will grow in a planter, container or pot. It follows from the anatomy of trees that their root and leaf masses are all ways in balance. This FACT allows you to control the mature size of many tree species. It presents a wonderful opportunity for persons with small and very small gardens to also enjoy the beauty of Southern African trees. However it is also true that some species wither when their roots are contained. To plant them in a pot will bring little joy and much frustration. Use this filter ("yes") to avoid disappointment when planting trees in containers.
Ignore this user input box if you have no interest in container/pot planting
Requirements: Sexes
You have the following choices for selecting tree sexes:
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Separate male and female trees
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Male and female flowers on the same tree
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Bisexual flowers on the same tree
Regarding the first choice, take note that only female trees bear fruit. Pollination is often not a pre-requisite for fruit bearing. However pollination is necessary for their seeds to be vibrant. Otherwise their fruit will be void of seeds or contain non-vibrant seeds. Species falling under the latter two choices will all ways bear fruit, albeit that such fruit bearing may be inconspicuous.
It is impossible (except for a few species) to tell male and female trees apart before they start to flower. In some cases it may take up to 7 years before a species reaches sexual maturity (start flowering).
Requirements: Drought tolerance
TreeBook allows you to select one of the following choices:
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Very drought tolerant
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Drought tolerant
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Needs modest water
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Needs much water
Tree species that grow in desert like climates were indexed as "very drought tolerant". They have developed special mechanism to cope with harsh desert conditions. One would think they are robust and will thrive in a wetter climate. Unfortunately this is mostly NOT the case. Desert species are particularly vulnerable to fungal attack on both roots and leaves.
It is generally true that deciduous species are drought tolerant. During winter, when their is no rain fall, they shed their leaves -thus reducing their water needs to a minimum. When there is a dry spell during summer, they easily shed their leaves, just to bud again when the rain comes. They are well adapted to such weather extremes.
Evergreen trees with small leaves needs less water than ones with large leaves. Species that grow in or near to river beds in their natural habitat, need more water than ones which grow on open plains.
TreeBook used all the above and more guidelines, including our knowledge regarding exceptions to these general truths, to index Southern Africa's tree species' drought tolerance.
Skip this user input box if you have no interest in the trees' drought tolerance and water needs.
Purpose: Attract birds
TreeBook offers the following choices:
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Fruit eaters
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Insect feeders
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Nectar feeders
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Nesting
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None
It was a difficult task to index bird attraction. Many tree species have more than one attribute that attracts birds. For example it bears fruit (which attracts fruit eating birds). During flowering the tree will attract insects, which in turn will attract insect feeding birds. Furthermore it may also offer good nesting opportunity. How should the species then be indexed?
We solved the problem by indexing what we thought (and what we found by research) the single attribute that is most prominent for attracting bird life.
We are not experts in bird behavior and hereby invite visitors to share their insights with us. Please complete the comment form on our home page.
Purpose: Provide screening
Screening is indexed in terms of the screening height that the user is looking for: "up to 2m", "up to 5m" or "up to 10m". The wizard then displays "fit for purpose" trees based on their mature size. There are two ways to achieve screening quickly: Buy large trees and plant them in close proximity, or buy fast growing trees and plant them in close proximity.
Purpose: Flower beautification
Beautification by planting flowering trees filters our data base according to the following user input:
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Showy flowers
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Showy flowers in profusion
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Flowers in profusion
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inconspicuous flowers
Showy flowers are exactly that. Unique in terms of size, color, form or a combination of these attributes. We provided a special search for trees which bear showy flowers in profusion.
Trees that flowers profusely may have mundane individual flowers, but they are produced in such quantity that it makes for a beautiful presentation.
We included the third choice for the benefit of users who specifically want trees with minimal or minute flowers.
As before, if flowering is not a priority, just ignore this user selection box.
Purpose: Value to game
You can select trees that have value for game by the following choices:
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Brows leaves
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Eat fruit
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Fruit may be poisonous
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No value
There are many eco-estates in South Africa where game is kept. Making a garden when game is around is a challenge. It is quite handy to know which tree species have no value to game. Hence the 4th choice.
The fruit of some tree species can be poisonous to game when grazed in quantity. We thought that this characteristic is important to game breeders.
The first two choices are self explanatory.