Monday, November 5, 2007

How to work on a sloping site for a garden...

Many front yards have a gradient, which makes mowing a lawn impractical. A low-maintenance alternative is to carpet the slope with easy-care ground-cover plants. Alternatively, you can create a rockery on the gradient. Embed rocks into the slope or, especially if the gradient is steep, terrace the slope by creating a series of low retaining walls with plantings in between. A terraced garden may be expensive and time-consuming to have built, but it allows easy access for maintenance and can be linked by shallow steps. Terracing can also create the illusion of space by combining open areas, for example linking gravel with planting beds.

When building a terrace, keep the retaining walls as low as possible and do not attempt to build a wall taller than 90cm - call in an expert instead. Clear weeds with a glyphosate-based weedkiller, then allow any soil added to the terraces to settle for a few weeks. Before plant¬ing, top up with extra soil to form a gentle slope leading back to the bottom of the terrace above.

Making a rockery

Rockery plants need an open, sunny site and good drainage, although the soil should not be particularly rich. If your soil is 'heavy', with a high clay or silt content, improve it by digging in grit or river sand. If the subsoil has poor drainage, dig out the top 30cm of soil, put in a 15cm base of rubble or road base, and then a 5cm layer of river sand followed by 10 cm of topsoil -hard work, but your efforts will be rewarded'.

When choosing stones to embed in a rockery slope, select the natural stone of your region, especially if natural rock is a feature of your area. Otherwise, common stones for rock gardens include limestone, which weathers quickly but is not liked by acid-loving plants, and sandstone, which comes in attractive colors. Other materials include driftwood, slate - which comes in grey, green and purple - and, if you can get it, tufa, which is lightweight and good for a small rockery.

Choosing rockery plants

Choose plants that are easy to establish, but not invasive. Along the top edges of the wall, plant prostrate alpines or small succulents so that they tumble over to soften the hard structure.To prevent alpines and succulents rotting at the base, plant shallowly with 3cm of the rootball above soil level and mulch with about 5cm of pea gravel or stone chippings. This will also conserve moisture during dry spells, control weeds and ensure that your plantings blend attractively into the rockery.

No comments: