Step by Step Guide to Establishing Australian Native Shrubs

The Australian flora has established a reputation as a tough, drought tolerant group of plants that are very low maintenance in the garden. Whilst this is generally true it is extremely important to realize that a bit of tender loving care during the first few weeks of establishment will give your native shrubs a flying start.

All types of shrubs will usually have received ideal conditions while they are in the production nursery. This generally means daily watering and constant nutrient levels to ensure rapid growth before they go to the retail outlet. It is absolutely vital that these plants are gradually weaned off these ideal growing conditions once they go into the ground. If they are suddenly cut off from regular moisture levels during hot dry days water can actually be drawn out of the root ball to the surrounding soil and result in severe wilting or even death of the plant. Consequently, following a series of basic steps will lessen transplant shock and allow the roots to penetrate quickly into the soil and find their own moisture rather than relying on irrigation.

1. Plant selection -€“ Ensure that the plant is not root bound. If the plant looks too big for its pot ask nursery staff to remove it from its pot so you can satisfy yourself. Also look for plants grown in containers that are designed to train the roots downwards
2. Preparing the hole – If possible use a mattock or trowel (depending on the plant size) to dig a hole considerably bigger than the size the root ball. The idea is to have a few cm of loose soil around the root ball to make for much easier root penetration.
3. Saturating the root ball -€“ One of the simplest and most effective things you can do to give your plant a good start is to completely submerge the root ball in a bucket of water before planting. This is especially critical during dry weather as is pouring some water into the empty planting hole.
4. Planting – Tease out any roots that may be curling around the inside of the pot and place the plant in the hole. It is important not to put organic matter into the base of the planting hole, particularly if it is a clay soil, as this can rob the roots of vital oxygen as the organic matter continues to break down.
5. Soil additives – Well rotted organic materials make excellent soil conditioners that will improve water and nutrient retention around the roots. It is, however, important to ensure a low phosphorus level for those native plants such as grevilleas, waratahs, banksias and acacias (to name a few). Reputable bagged soil conditioner products will be clearly labeled as to whether they are suitable. A home grown alternative is to use very well rotted cow and horse manure. Mix the well rotted organic material (and if the soil is likely to dry out regularly also use expanded water storing crystals) with the topsoil that is going to go around the roots in the top 15-20 cm of the planting hole. Then backfill the hole, firming the soil mix into the gaps.
6. Before watering the plant in form a saucer around the plant to retain water while it is soaking into the soil. This is particularly important for soils that allow only very slow percolation of water into the surface. Indeed, if this is the case then it is worth treating the topsoil with a wetting agent at planting time as well.
7. If you know that weeds are going to be a problem for you then multiple sheets of newspaper can be laid around the plant before covering in a 10-20cm thick layer of mulch. Coarse woody mulches are a good option as they not only help with water retention but also suppress weeds. Ensure that the base of the stem is kept clear of the newspaper and mulch for several cm.
8. Tip pruning is another must if the particular shrub you are planting lends itself to a dense, bushy habit. Simply pinch out the growing tips at planting time and repeat this every couple of months during the first year of growth. Not only does this keep the plant more compact, it also greatly increases flower production.
9. Staking is best avoided if at all possible. The stems of woody plants are naturally strengthened as they blow in the wind. If a plant has developed a leggy stem due to being packed in too tightly during its production and you have no alternative than to plant it like this then use three stakes in a triangle and secure the plant with a pliable soft material that will give support but still allow gentle movement of the stem in the wind. Regular tip pruning will also help the plant to create a more stable shape such that the stakes can be removed as soon as you are confident the plant is stable.
10. If frost protection is necessary then a temporary shelter of a tree guard or sheet of Hessian can be wrapped around the plant during winter. Products known as antitranspirants (eg Stressguard) can also be sprayed onto the foliage to minimize damage.
11. If there is a lack of natural rainfall and you notice your plant wilting then supplementary watering is indicated. Upended cut down drink bottles or water spikes can be particularly useful to get water down to the root system if water penetration is difficult in your soil. It is extremely important to water deeply if supplementary watering is required as this will encourage the root system to grow downwards to seek out the natural moisture in the subsoil thus making the plant more self sufficient.

It should be pointed out that not every step is absolutely essential to success but we have mentioned a host of ideas that can be used which will all add up to faster and more successful establishment of your native shrubs. Once they are off and growing most of them will be more than capable of looking after themselves.