Gardening up and down hill creates unique challenges!

Many houses are above street level and have a sloping front yard. If it is a gentle slope, you can garden it as you would a flat site but a steep slope is a different matter. If you build a retaining wall at the base of the slope as your front fence, you will make the slope less steep and, the higher the wall, the less steep the slope will be.

Behind the wall will be an area of deep, welldrained soil that should be ideal for flowers, shrubs or ground covers. But before you plant, consider these points:

• Understand aspect
  The sun is directly overhead at Christmas but for the rest of the year it streams in from the north, getting lower and lower in the noonday sky until mid-June. If your house is on the north side of the slope it may shade the soil for much of the year, so you will have to choose plants that can cope with winter shade/summer sun. A south-facing slope will remain cooler throughout the year since the sun's rays will strike it at an oblique angle. A north-facing slope will be very hot and sunny and it may need a lot of water if the plants you choose cannot cope with dryness.
  
• Soil type
  Sandy soil will dry out fast but has good drainage. Clay soil will hold water longer and should also be well-drained. If you have sandy soil, avoid plants that need a lot of water.
  
• Steepness
  The steeper the slope, the less suitable grass becomes. It is hard work and dangerous to mow a steep slope and you will have a better-looking garden and less work to do if you plant the lot with ground covers, flowers or shrubs.
  
• Privacy or openness?
  If you want privacy, stand in the street and look towards the house. Now estimate the height a shrub needs to be to block the view of your home. Atop a retaining wall you may only need a metre or so of growth to achieve total privacy. If you want openness, plant ground covers and low flowers.
  
• Preventing erosion
  Bare earth on a slope will wash away with every downpour. Plants will prevent this, and the best choices will include ground covers that form roots at intervals along their stems; spreading, clumping species, and those with many small stems arising from the base.

Good plants for slopes:
Convolvulus mauritanicus
Dietes grandiflora
Agapanthus
Lantana - 'White Lightning'
Kangaroo paws
Cerastium tomentosum
Diosma
May bush
Mondo grass
Chinese plumbago
Ivy
Strelitzia

Create your own sloping garden

You'll need
Treated pine sleepers (we used 2.4m x 150mm x 75mm at about $21 each); 'deformed' (dimpled) 12mm (Y12) diameter reinforcement bar (about $10 for 6m) to pin the sleepers into the ground; waterproof glossy black paint

Here's how
Step 1
Study the contours of the area for your stepped garden. Clear the site of turf and weeds. Design your beds around distinct slope changes and use string or garden twine to mark an outline for the beds.

Step 2
Cut the sleepers to size and paint with all-weather black gloss paint. Secure the bottom sleepers to the ground with Y12 reinforcement rods. They should penetrate the ground to a depth of twice the height of the sleeper. Check that the sleepers are level.

Step 3
Butt-join the ends of the sleepers to make the boxes and secure with galvanised decking spikes. Alternate the joins for extra strength and visual interest. Position a water bowl, and mulch with pebbles.

Step 4
Plant into a soil of garden mix, sand and compost. This will provide the good drainage essential for these natives, as well as the right range of nutrients.

Seaside slope
The problem of a steep, eroding bank of sandy soil makes a front yard or backyard a wasteland! Our solution provides usable level space and wraps it with a beautiful, dense planting for privacy from the street.

Step 1 Excavation
First the site was excavated to make room for a new paved terrace. During excavation, several large boulders were uncovered. These were later incorporated into the two semicircular retaining walls which were built to enclose the terrace and hold the remaining slope in place.

Step 2 Soil
Because the natural soil was pure sand, a generous amount of composted organic matter was bought from a landscape supply company. It was incorporated into the top 30cm to improve the soil's fertility and help it retain moisture.

Step 3 Irrigation
An automatic watering system was also installed to help minimise time spent on garden maintenance and to ensure that the plants received adequate water during the establishment phase.

The owners, who are neither experienced nor enthusiastic gardeners, wanted plants which were easy to maintain but which would also provide cut flowers for the house and privacy and shelter for the new terrace.

Step 4 Plants

1. Arctotis x hybrida. A spreading ground cover with brightly coloured daisy flowers.

2. French lavender. A metre-tall, dense rounded shrub ideal for these conditions.

3. Leucospermum cordifolium 'Goldie'. This will grow into a 2m tall privacy screen along a fenceline.

4. Kangaroo paws. Position a clump of these bird-attracting plants either end of the lavender planting.

5. Seaside daisy and Swan River daisy. These low, long-blooming ground covers are excellent used along the driveway edge.

Source:Better Homes and Gardens TV