Planting Hedges

A stunning hedge helps to define borders, divide areas into rooms and bring a little formality to a garden. They take time and patience to establish but most will last for many years with nothing more than a regular water and a quick ‘hair cut’ every month or two.

Most hedging plants available in garden centres are suitable for a range of climates and are quite adaptable to different conditions. Slower growing plants take longer to achieve the desired size and shape but the result is more compact hedge foliage that requires much less maintenance and probably lasts for many more years than a fast growing hedge.

The secret to a beautiful, low maintenance hedge is choosing a variety that suits the location and conditions.  By choosing wisely, the need for ongoing care is reduced and the hedge will perform well in the garden.

Box or buxus hedges are one of the most popular as their small leaf is ideal for clipping into well-defined formal shapes and topiary. Box hedges can be used as a simple border or used to create elaborate patterns that become an impressive garden feature in their own right. Varieties are available that grow from 50cm to 1 metre so they are suitable for defining garden beds or as screens to separate garden rooms.

Stunning hedges can also be created by any number of shrubs planted closely together including rosemary, lavender, conifers, nandina, jasmine and lillypilly but a great deal of research should be undertaken before purchasing and planting.

Know the final height and thickness that the hedge should be and ask the advice of a horticulturist for which to choose. Plant labels will give an indication of hedge height and width but plant growth varies depending on conditions so local knowledge should always be sought. At the very least, wander around the neighbourhood and see what is thriving in other people’s gardens as they should have similar conditions to your own.

Consider if the hedge will receive the same amount of water and sunlight along its full length. If part of the hedge is shaded and part in full sun, the way in which it grows will be different. Take this into consideration when choosing a hedge variety.

Also, take soil samples and check the pH in several places along the line on which the hedge is to be planted. It can’t be assumed that the pH will be the same even in the same garden bed so any inconsistencies should be corrected and the hedge variety chosen to suit the soil.

It might be much less expensive to plant smaller plants but it may take several years for the bushes to get to the height and width desired so it may be worth investing in more mature plants to speed up the process.

When selecting the plants from a group at the garden centre, pull them all out into the path and choose those that are uniform in size, width and also denseness of the foliage at the base. Small differences don’t look like much when the plants are small but become quite obvious as they mature.

It’s a good idea to purchase a few extra plants and keep them in pots or other garden beds.  If one or two of the plants in the hedge fail, these can be transplanted quickly to fill up the resulting hole.

PREPARATION AND PLANTING
Autumn is probably the best time to plant a hedge in WA since the soil is still warm and the plants have several months of rain to help them settle in before the heat of summer.

Put a lot of effort into preparing the soil since shrubs will be planted close together with their roots competing for nutrients and space. Dig along the trench or garden bed, taking out the roots of other competing plants. Enrich the soil by adding plenty of cow manure and compost. A soil wetting agent is essential in WA and adding water crystals will offer extra water holding ability.

Measure the width of the garden bed and set up a string line down the middle to ensure that the hedge is straight. Then, calculate the planting width and mark this using a spray marker ensuring that when each hole is dug, the marks can still be seen. The distance for planting will differ depending on the plant variety chosen but make sure that the two end plants are half this distance away from the edge of the garden bed.

Dig the holes and place the plants in at the same depth as the soil in the pots. Once in the ground, give the plants a light trim using a line level to keep it straight. It’s much better to undertake regular light trims to thicken the base and foliage of the shrubs than to wait until the hedge gets to the height required and then trying to get it into shape.

If the plants are in an open position, they should be staked to prevent them from being blown over or growing on an angle. Tie the plants to the stake at several places using a material that stretches but remove them once the plants are strong and able to stand up on their own. Mulch the bed to help keep the soil temperature even, to suppress weeds and to help the soil retain water. Apply a slow release fertiliser to the soil surface.

PRUNING
When hedges are in active growth, pruning every four weeks will give the best results. This will keep the foliage on the hedge compact and tight and there won’t be a chance for the hedge to get out of hand or unruly. When left to grow too long, the risk of uneven growth and holes in the hedge increases so regular but light trims are not only best but actually much less work.

When shaping a hedge, it is important that the finished product has a slight wedge shape with the top foliage a little narrower than the base. This allows all the branches access to the light and will result in a healthier hedge with foliage all the way to the ground level. Always prune the sides first and the top of the hedge last.

It’s probably not necessary to rig up a string line for a quick trim but for a full renovation prune, this will be essential to keep the hedge straight on all sides. Simply set up a stake at each end of the hedge and tie the string tightly at the desired level. These can be used lengthwise and widthwise as needed. Renovation or hard pruning may need to be done from time to time but should only be done in winter and remember that not all plants will respond well to a heavy prune. Many, such as lavender and rosemary, will resent being cut back to the wood so research the plant first or undertake the renovation with several, not so drastic prunes several weeks apart.

Every few minutes, take time to stop, step back and assess the hedge.   This will make sure that the final result is exactly what you are after and that the lines are straight.

For large hedges, consider investing in electric or petrol hedging shears. These make quick work of a hedge and often make creating a straight line a little easier. Bigger is not necessarily better with power shears though. Choose one that suits your build, hands and strength as you will need to hold it at different heights; a large hedger will soon become heavy and potentially dangerous. It is far better to choose a smaller, more lightweight one that might mean more passes over the foliage but offer more control and comfort.