By Kate Wall
For very large gardens, mass planting with reliable landscaping plants can be the most effective way to achieve an attractive and easy care garden without requiring extensive gardening know how. Mass planting can also mean simplified maintenance, as all the plants will be happy with the same maintenance tasks.
Landscape garden plants are selected for their hardiness and attractiveness in addition to their ease of maintenance. They are usually shrubs, small trees or grasses. Mass planting is usually desired to give a neat uniform look over a large area and is desired to be long lived. Short lived annuals or perennials are best avoided due to the need for frequent replacement. Mass plantings of annual or perennials can be very effective but is considered to be high maintenance so is rarely done in large domestic gardeners unless the owner is a very keen gardener.
Mass plantings happen as one major landscaping project rather than adding a plant here and there to a garden. As with any project good planning will greatly contribute to the success of the project.
Because mass planting is the repeated planting of many of the same plant or plants, if problems arise, it is likely to affect the entire planting. In a small garden the loss of one plant variety may not significantly impact the entire garden however in a mass planting the entire garden could thrive or fail based on the success of the plant choices.
Once you have decided on the style of garden, ensure you match your plant selection to your climate, soil type and other local conditions. Plants will always perform better when grown under conditions which suit their needs. Poor plant suitability will mean that the entire planting will struggle, but with good suitability you will have a thriving and low maintenance large garden which looks amazing.
In addition to climate and soil type, consider factors such as slope and the potential for erosion; access to water and ease of watering the new planting; is the area likely to be affected by floods or bush fires; is the planting likely to be impacted by grazing animals such as stock, kangaroos or rabbits; does the proximity of nearby trees affect the amount of sunlight or water availability and will this change over the next 5 years. All of these potential problems can be overcome with good plant selection and good set up.
Soil improvement is best done before planting begins. It can be difficult to add large amounts of compost or other soil additives once planting has occurred. Take the time to understand your soil and make improvements as required in advance of planting. You can find more information about soil types and how to improve them here.
If your site is steep or erosion prone, you may need to look at using erosion control measures to prevent the new plantings from washing away before their roots can be established. Lomandras are amongst the most successful plants for stabilising erosion prone soils, with dense deep roots which hold soil in place. They are ideally suited to mass plantings and with the large range of lomandras varieties available they can be selected to give a variety of different affects and to suit different climates in addition to coping with other factors such as flooding, bush fires, drought and grazing pressures. Steep sites may need additional assistance to assist small plants to become established. Coir mesh is idea for erosion control, and will also deter pests which scratch and dig such as scrub turkeys and bandicoots. It will break down over a period of 3- 5 years providing critical protection as the plants establish.
New plantings will need to be watered regularly as they establish. Ideally mass plantings are reasonably drought tolerant and will not need extensive watering once established. Hand held watering is rarely effective in large gardens, so a sprinkler system will be required. This may not need to be permanent, but you will need to check with your local water restrictions before putting in a sprinkler system.
Ideally time your planting to occur in spring (or autumn in warm areas), allowing the plants to get started without threat of frosts or heatwaves.
It can be tempting to begin with larger plants so that you achieve something of an instant effect. Mass planting can be expensive as many plants need to be purchased in one go to fill a large area and is usually designed as a long term garden. Starting with smaller plants will not only save significant expense, small plants will usually establish faster than will larger plants. Over a period of two years small plants can often catch up and overtake the growth of larger plants and will have a shorter establishment phase.
Once planted, the garden needs to be mulched. Use a chunky bark mulch which allows water to penetrate easily and will last longer before breaking down. The mulch will be important for water conservation, reducing plant stress and also for weed suppression. Weeding a large garden can be a daunting task so good weed management will be worthwhile. Using a product called “Weedless” will greatly reduce germination of weed seeds without needing to resort to using poisons. When weeds do appear, pull them out before they get the chance to go to seed, starting the weed cycle all over again.
Your mass planted garden should receive regular watering and regular small amounts of fertiliser in the first year. After that an annual or bi-annual feed and prune is often all that is required in addition to the regular weeding and watering as needed to keep your mass planted garden looking neat and lush.