Choosing trees for small landholdings
Although planting a tree may seem relatively simple, getting the wanted results needs careful species selection with the end use in mind. The wrong tree in a poorly chosen position is not only a waste of money, but can be a nuisance or even dangerous.
Carefully consider why you want to plant trees. It is unlikely you will find one tree to do several jobs successfully, so consider specific plantings for particular purposes.
When choosing varieties of trees to plant on your property, three vital questions need to be answered:
Why?
Why are you planting trees? Choose tree varieties with the correct characteristics to suit your intended purpose. Trees have many uses on small landholdings, including:
- aesthetics
- wind erosion control
- stock shelter
- nature conservation
- waterlogging control
- salinity control
- possible commercial production.
You must know what you want the trees to do for you, so you are clear as to what characteristics you need from the trees. Remember, there are no ‘miracle’ species that will do several very different tasks.
Where?
After it is clear why the trees are to be planted, think about where in the landscape you intend to plant the trees to achieve the particular task.
Where are the prevailing winds coming from? Where will the stock be that need the shelter? Where will they look best from the house or from the road?
Trees will struggle and may not survive if they are planted in an environment they are not suited to. For each specific location you intend to plant trees, you must consider the specific environmental factors of that area such as soil type and rainfall.
Even within the property boundary, although rainfall may not vary significantly, soil types must be checked at each site, as they can vary widely (e.g. well drained, dry or wet).
What?
Use this information to determine what species will do the task best. Many large tree growing organisations such as the Forest Products Commission or Men of the Trees have tree selection catalogues. These are very useful, as they also list preferred rainfall, preferred soil types, mature height, growth habit, uses and a general description.
Observe the golden rules
Although the tree seedlings may not be particularly expensive, all the preparation, labour and maintenance add costs to tree planting.
To achieve a high survival rate, there are some golden rules that must be considered before choosing and ordering your tree species.
Plant in the correct rainfall zone
Rainfall is critical. Unless there is an unusual situation (such as a large freshwater seep at the site) select trees from similar or lesser rainfall zones to your planting site.
For example, if you are in a 650mm annual rainfall zone, plant trees suited to 650mm of rainfall or less. Don’t plant a tree suited to a 900mm rainfall zone.
Trees suited to a higher rainfall zone may survive for a few years but when their water usage peaks they may die if their annual moisture needs are not met.
Know your soils
Soils are also a very important consideration. Go to the planting site and dig a hole with a posthole digger or shovel, preferably to one metre deep, to find out what type of soil it is.
How deep is it to clay? How deep is the deep sand?
You don’t need to be a soils expert, as most nursery tree selection lists refer to light or heavy loams, clays, gravels or sand.
In some cases, such as limestone-based soils on the coast, the soil pH would also be important.
Ensure good site preparation
Site preparation is critical to success:
- Total weed control is essential for a one metre radius around each tree seedling and this area must remain weed free for at least one year after planting.
- Ripping the planting lines at least 40cm deep and preferably on the contour one year before planting will help root penetration. If ripping down a slope is unavoidable briefly lift the ripper out every 20m to avoid water erosion occurring in a continuous rip line.
- Rip and mound the soil in waterlogged or salt affected sites to provide seedlings with a more favourable growing environment whilst getting established.
- Site drainage may be necessary as trees should not be planted on a site that will sit in water for weeks. To avoid legal issues, you should discuss any drainage proposal with your local government authority and neighbours. In the case of drainage of saline land, approval from the Department of Primary Industries and Regional Development may also be required.
Plant local native species
Try to plant the local native species of your area if they are suitable to your requirements. The local native species are not the mature trees that were planted by someone many years ago, but the local remnant vegetation.
It is better to plant local native species because they:
- have adapted over thousands of years to the local climate and rainfall
- best suit the local wildlife
- are more suited to the local rainfall
- are more resilient to local diseases and insects
- perpetuate the local species.
However, local native species may not be suitable if the local environment has changed, for example because of salt encroachment.
Don’t plant weeds
Some tree species are highly invasive and can create major problems for you and the environment. Species such as willows and poplars create severe problems, particularly around waterways.
Even some non-local native plants such as some wattles (Acacia spp.) can spread out of control. It is easy to plant such problem species, but very costly to control them. Check the weed status of any trees you consider planting.
More information on tree species can be found on the Department of Biodiversity, Conservation and Attraction's FloraBase website.
Do a property plan
Plan where the trees are to go as they will be there for a long time. Spur of the moment plantings can be a major nuisance. If you plant a major line of trees in the wrong spot you have two options:
- develop your property around them, then everything else is also in an awkward position
- pull them out, which makes it all a waste of time, money and effort.
If you intend to plant some trees on your small landholding, it is strongly recommended to develop a tree planting program as part of a property plan.
By using an aerial photograph of your property, you can plan where to plant the trees for maximum effect with minimum inconvenience to other activities on the block. Furthermore, the essential pre-planting tasks can be comfortably planned for and achieved.
Planting trees may appear simple, but to be successful there are several steps that must be carefully completed in sequence. You must allow time for:
- investigating the ‘why, where and what’ of the tree planting as outlined above
- ordering tree seedlings in November and not using cheaper surplus nursery stock if these varieties are not suited to your intentions
- organising labour and specialist machinery well in advance (such as tractor, tree planter, small herbicide sprayer and so on)
- good site preparation, especially weed control
- planting at the appropriate time
- fencing from stock if necessary
- maintenance and replacing dead seedlings.
With correct species and good preparation, watering over the first summer should not be necessary, except in drought conditions.
Some uses for trees on small landholdings
Windbreaks
The advantages of a windbreak can extend into a paddock up to 20 times the height of the windbreak trees, but again, species selection is important.
The foliage must extend to ground level to prevent increased turbulence and wind tunnelling, which may cause wind erosion under the trees. The foliage of the windbreak needs to be semi-permeable, as a dense barrier type of foliage results in a poor windbreak due to increased turbulence on the leeward side.
Permanent fencing beyond the extremity of where lower branches will grow is important in windbreaks so that grazing of lower branches does not result in wind tunnelling and erosion. Thick foliage in the lower storey can also help to suppress grasses, reducing the fire hazard.
Gaps in windbreaks should be avoided as wind speed is increased through these gaps. It is important to replant any tree deaths as soon as possible.
Wildlife attraction
Trying to recreate a natural environment is a good way to attract wildlife onto your property.
Such a revegetation program should include both upper and lower storey tree species, along with local native shrubs. Different native fauna feed on different levels within the vegetation, seeking particular foods such as nectar, insects and seeds.
Some farmers have observed noticeable insect pest reductions after attracting native birds with such plantings.
Doing some research before designing the planting will allow you to select plant species that will attract a rich diversity of fauna. Plants may include grevilleas, callistemons, banksias, acacias and eucalypts.
On a remnant vegetation site, it is important not to clean-up the site, as old logs and rock piles can also harbour wildlife. But be vigilant for pests such as rabbits that may also use such harbourages.
It is also a good idea to link stands of remnant vegetation with shelter belts or windbreaks to provide wildlife corridors between the stands.
Salt revegetation
Revegetating a salt affected area aims to increase the usage of water falling on the land surface before it recharges into and adds to the saline groundwater table.
However, the planting of local native species may not be possible on saline sites, as the original environment has changed and these species may not now survive in it.
Different plants have different tolerances to various levels of salinity. Well before planting, the degree to which salt has affected the site must be determined.
Barley grass is often used as a rough indicator of the degree of salinity of a site, but we strongly recommend soil and water testing and if the planting is of a commercial nature, a hydrological investigation is warranted.
In the meantime, though, an initial approximate classification is as follows:
- Mildly salt affected: thick barley grass.
- Moderately salt affected: patchy barley grass.
- Severely salt affected: bare ground.
Highly saline sites are difficult areas to get trees growing on at first. It is best to seek advice from your local farm forestry advisor or local agricultural consultant.
One strategy is to fence and drain surface water, where appropriate, before planting one or two varieties. Once established more varieties can be introduced as the site improves. Site preparation such as mounding can be crucial on saline sites.
Fodder
Some trees and shrubs are useful as fodder but you must ensure that stock still have access to a balanced diet, which may mean providing supplementary feed.
Tagasaste is a common fodder shrub particularly for cattle, with some landholders also using Acacia saligna and carob trees.
Saltbush on salt affected land may be a fodder possibility, but access to good quality fresh water and supplementary feeding are essential.
Wood production
If you are considering trees for commercial timber production, the viability of the proposal, minimum volumes and distance to processing centres, and current and future markets for the product must be investigated.
Some large landholders grow trees for sawlogs or pulpwood, or particular mallee species for eucalyptus oil production.
There may also be some possibilities to grow specialised craft wood. In any case, plans for commercial plantations need to be thoroughly studied.
Establishing trees on a small property can help improve aesthetics and serve many useful purposes but careful pre-planning is essential to achieving the right results.