Plants can look great when surrounded by paving, or when interspersed with pockets of plants. Either way, paving and plants have the potential to create a visual effect that is better than when either one is used alone. There are also potential problems though.
ADVANTAGES OF PLANTS SURROUNDED BY PAVING
Plants visually soften the paving.
The area doesn’t get as physically hot.
The cost of paving is reduced.
Difficult paving (requiring cutting of pavers, dealing with curves etc) can be avoided.
DISADVANTAGES OF PLANTS SURROUNDED BY PAVING
Plant roots can lift and damage paving.
Paving reduces water supply to plant roots (growing below the pavers).
Paved areas concentrate water run-off, channelling it to the lowest point, creating soggy spots or erosion.
Large trees can lower the water table and cause foundations to drop, resulting in cracked paving.
Weeds may grow in the gaps between the paving.
Create visual patterns with plants and paving to contribute to the formality or informality of the garden style. Some examples:
a checker board pattern with paving blocks and squares of plants
paving and plants in parallel lines
circular paving with a central bed containing a small tree for height or low-growing shrubs or groundcovers surrounding a birdbath or statue.
A paved area with low growing grasses in the gaps between the pavers.
Stepping stones meandering through a garden bed filled with low growing shrubs and ground covers.
Pavement that includes permanent planter boxes filled with colourful plants.
Plants can be used to soften the changes in level that occur when paving on steep sites.
Low clipped hedges give a neat, defined edge to the paving. They are high maintenance, requiring regular clipping through the growing season to maintain the sharp outlines, but they certainly are worth the effort. If you have a creative flair, the hedge can also feature topiary shapes (clipped spheres, animals, etc.).
Place raised edging tiles along the edge of paving. This not only keep soil off the paving when it rains or when you water the plants, but it also allows you to top up garden beds with a layer of mulch. Furthermore, a good quality edging looks smart and provides a neat finishing touch to the garden.
PLANTS THAT CAN BE USED BETWEEN PAVERS
As a general guide, choose plants that won’t be overly vigorous and invasive, and that won’t cause problems with roots lifting the pavers.
In large, open paved areas, temperatures can rise significantly on hot, sunny days, so choose hardy plants that can tolerate heat and glare.
For new plantings, especially those in larger beds, use gravel mulch to stop the soil drying out. The gravel also provides an interesting textural contrast with the pavers.
Some of the best plants for planting in paved areas:
Lawn grasses are especially good for paved areas subject to lots of foot traffic. Simply mow over the grass patches as required. The drawback is that they can be high maintenance, being more prone to drying out than larger lawn areas. Also the edges need to be kept very neat otherwise they can look terrible.
Small-leaved groundcovers, especially those that do not spread far, eg. Chamomile, Thyme, Golden Marjoram, Dichondra, Canberra Grass (Scleranthus biflorus), Native Violet (Viola hederacea), Snow-in-Summer (Cerastium tomentosum), Sedums.
Small clumping plants, eg. Blue Fescue and Mondo Grass.
Self-seeding plants, eg. Alyssum, Heart’s ease (Viola tricolour), Forget-me-nots, Love in the Mist.
Low spreading conifers – best suited to larger spaces; they may need trimming to stop them covering the paving.
TREES IN PAVING
It is often difficult to grow a lawn under trees – it’s simply too shady and dry for grass to grow under the tree canopy. Paving can be an excellent alternative, providing a clean, firm surface that can be used as a shady outdoor play area or for sitting and relaxing in a favourite garden chair.
When paving around trees, it is important to keep root damage to a minimum. If you can’t pave right up to the tree without cutting through major roots or if you think the roots will lift the paving, cover the area at the foot of the tree with gravel or bark mulch. The pavers can be positioned one or two metres beyond this.
Avoid building the soil up around the trunk to create a level surface for the paving. Soil around the trunk will rot the bark and may prevent oxygen reaching the roots that are buried below the newly added soil.
Also remember that paving will prevent water reaching the roots under the paving. One or more deep watering tubes can be incorporated into the paving to overcome this problem.
Some varieties of trees and shrubs drop berries that can permanently stain unsealed paving, particularly terracotta and pale concrete. Varieties to watch are Fatsia japonica, some palms, cotoneasters and blackberries.
If you decide to include steps or a retaining wall in a paved area, plants can still be included. Incorporate planter boxes in to the step, or disguise the change in level with cascading plants.
You can also make a feature of changes in level by creating a sunken garden bed in the middle of the paved area.