Your lawn renovation process can be as simple as amending the soil environment back into the favour of desirable species, along with aeration and weed control, or as complicated as completely removing the existing vegetation and then re-establishing the lawn area.
Between these two options is changing the dominant species of lawn grown or replacing the lawn that has died by planting new plant material into existing live or dead lawn.
This guide explains your renovation options, detailing key points to the renovation options you have, and giving an overview of each of the most common renovation practices for Aussie lawns.
Once the cause/s of lawn decline is identified, a lawn management program can be established that will best upgrade the lawn whilst taking into consideration the existing conditions, budgetary constraints, and the desired lawn quality. In the majority of situations, a lawn management program would fall into one of the following categories:
- Initiation of a program of sound cultural practices.
- Renovation of the lawn
- Total re-establishment of the lawn area.
In each program, the lawn grasses, soil conditions, thatch levels, environmental conditions, and existing perennial grass weeds must be evaluated.
Initiation of a Program of Sound Cultural Practices
Many lawn areas can be brought to acceptable quality levels by simply altering lawn management practices. Lawn grasses that can be improved in this fashion have many acceptable characteristics but are in an undesirable condition due to improper mowing, irrigation, fertilisation, pest control practices and/or lack of direct sunlight or overuse.
For a program of this type to work effectively, the existing lawn area must be comprised of a desirable lawn species and/or cultivars, have adequate density (or be capable of becoming more dense), have acceptable soil conditions, have a moderate thatch level, and have undesirables such as perennial grass weeds in manageable quantities. To implement a program of this type, the following process is followed:
- Soil tests are completed to evaluate amendment and nutrition requirements,
- A tailored amendment and nutrition plan is developed that suits the lawn being managed,
- Amendments are applied to balance the soil for optimum fertiliser performance, and
- Assessments and recommendations on mowing practices, irrigation requirements, and pest and disease management
Once current management practices are evaluated and modified to promote healthy vigorous lawn; appropriate mowing, watering, fertilisation, and pest control practices, your lawn can be brought back to the desired condition.
Appropriate Lawn Maintenance
Any high use lawn surface requires the highest level of maintenance to ensure the asset can tolerate the stresses of the wear experienced.
Mowing frequency and mowing heights vary considerably depending on the turf type and the desired finished look. However, under restricted watering conditions, a mowing program involving the ‘one third’ rule is preferred. This rule involves the removal of no more than one third of the grass blade at anyone mowing. This rule helps to maintain maximum lawn root growth as it has been shown that removing more than one third of the grass blades may cause root growth to cease while the leaves and shoots are regrowing.
Key mowing principles include increasing the mowing height as this leads grasses to develop a deeper root system, and ultimately improve the depth at which water can be extracted. Higher mowing heights also shade the crowns and the soil from solar radiation.
Mowing Top Tips
Mowing increases lawn density so lawns should be mowed as regularly as time and budget will allow.
- The lawn should be mowed in a different direction each time.
- Lawns without irrigation should be mowed at the higher end of the optimum range.
- The lower you mow the higher the input costs will be to sustain a quality lawn surface.
- Renovation Programs of this type are usually carried out in spring and summer to maintain a healthy lawn environment. Lawn renovations when conducted without adequate growth is detrimental to lawn health, leading to increased disease pressure in particular, due to a lack of lawn vigour and the restricted period of lawn recovery.
- Therefore, renovation timing should be more closely tied to the patterns of plant growth. The optimum growth and development of every lawn species is restricted to a specific temperature range. Temperatures outside of optimum, limit to an increasing extent the amount of lawn activity and the recovery time after renovations. Soil temperatures in particular, govern the rate of lawn growth.
Soil Balance and Amendment
Lawn grasses obtain thirteen of sixteen essential nutrients from the soil via the root system. Therefore, the nutrient status of the soil is critical in ensuring that the appropriate level of nutrient is available to ensure the lawn has optimal growing conditions.
A lawn growing in a well-balanced soil will outperform undesirable weed species and will be more capable of tolerating the stresses experienced during the lawn season. More information on soil balance and soil amendments can be found in our Guide to Soil Amendment and Nutrition Management
CRN fertilisers, such as Maintain, Maintain mini, and Turfmaxx are LawnPride product choices with varying NPK ratios and particle sizes. These professional products offer greater fertiliser efficiency over differing lawn growing regimes and conditions. CRN fertilisers will control the release of Nitrogen for up to twelve weeks maintaining growth habit and reducing mowing frequency, clippings, and pest & disease problems.
Common Renovation Practices
Aeration of your lawn should be carried out on a regular basis. Under restricted watering conditions, strategic aeration for couch grass is called for and may best be done prior to irrigation or when a rainfall is pending. Aeration reduces surface compaction as well as improving water, air and fertiliser moving into the soil profile.
Effective aeration can also improve the soils physical properties, particularly in relation to infiltration rate, and will maximise the effectiveness of rainfall and irrigation. Research has found that aeration can also be used effectively to leach out sodium and excess salts, as well as permit the entry of water, air, and fertiliser into the root zone.
Your local equipment hire company should have a lawn aerator and there are many turf renovation contractors who can help with the process. There are also a wide range of aeration options available for purchase, from shoes with spikes, to spiked rollers you fill with water, right through to motorised aeration machines for the lawn enthusiast.
Excessive thatch accumulation is a problem in many lawns. Thatch is a layer of organic material consisting of tightly intermingled, living, and dead plant tissues derived from crowns, stems, and roots. These parts of a lawn plant have relatively high lignin content.
Lignin is an organic compound that is highly resistant to microbial breakdown. Accumulation of a thatch layer occurs when the production of organic material (such as lignin) exceeds the rate of decomposition within the zone between green leaf tissue and the soil surface.
To assess thatch accumulation, remove a section of grass and soil from the lawn using a knife or shovel, and measure the depth of accumulated thatch. Depths greater than 12mm indicate that corrective measures may be needed to reduce the thatch layer. Measurements from several locations through the lawn area are needed because of the variable nature of thatch.
If the thatch layer is thicker than 12mm inch lawn vigour can be reduced. Thatch can also be reduced by vertical mowing. Vertical mowing should be done when the lawn is actively growing and should be avoided during periods of temperature and moisture stress. At this time, slow growth will reduce the recuperative capacity of lawn and increase weed encroachment.
Scarification is the mechanical removal of plant material (thatch) from the lawn surface. Surface thatch naturally forms within a lawn surface and is generally a benefit to a healthy lawn sward. However, when the thatch gets too thick it prevents important nutrients such as water, fertiliser, and oxygen from getting to the grass roots. It can also harbor pests and diseases and also make the lawn spongy and hard to mow at the correct height.
Scarification should be carried out in late spring or early summer with adequate time for the lawn to recovery before play recommences. Both dead and living plant material is removed during the scarification process, and the living plant matter can be re-planted into a prepared surface to effectively replant new areas of areas that are badly worn on other areas.
There are many turf renovation contractors who can help with the scarification process. There are also a wide range of scarifying machines available for purchase for the lawn enthusiast.
Topdressing a lawn refers to the process of applying a dressing of materials over the lawn’s surface.
Topdressing material usually consists of a material such as pure sand, or soil and sand. As the topdressing you choose will eventually become a part of the root zone, it is important that you understand what topdressing material your lawn requires.
Topdressing your lawn has many benefits including;
- Topdressing helps keep the lawn’s surface level,
- Topdressing your lawn regularly helps prevent the build-up of thatch and helps it naturally break down.
- Using sand-based topdressing can improve your soil’s drainage and firm up the surface. This works particularly well after aeration as the topdressing can be worked into the soil through the holes left behind.
- Using a sand / soil topdressing blend can increase organic matter, improve water holding capacity if your soil is too sandy, and provide addition nutrition.
- The right topdressing material helps stimulate grass growth in lawns and betters the soil structure of the already existing root zone and can improve your lawn’s resilience.
- Topdressing with imported material could have a significant effect on the performance of tour lawn. This is due to the fact that the imported topdressing material may be contaminated with weed seeds and the fact that it is being applied above your pre-emergent barrier where no protection can be offered. This is only an issue when contaminated topdressing material is utilised.
Renovate Lawn by Planting New Grass (overplanting) into Existing Live Vegetation
In some situations, a poor lawn requires more than improved cultural practices to reach an acceptable quality. In such cases, renovation of the lawn can be beneficial. This program can upgrade lawn by bettering lawn appearance, density, disease resistance, wear tolerance, and shade and drought tolerances.
To overplant into live existing lawn, proper soil balance, drainage/aeration, pH, and fertility should exist, thatch levels should be minimized, and undesirables such as perennial grass weeds should only be present in manageable numbers.
When the area in need of improvement has large populations of perennial grass weeds, selective herbicides can be used to kill undesirables, followed by overplanting to repopulate areas with desirable lawn species.
As in establishing lawn from stolons, there is one period when renovating by overplanting is most successful. In Australia, the best time of the year to overplant is from September through to February.
Overplanting during this period allows warm-season grasses to develop adequate root systems before the onset of the winter months where many warm season grasses become dormant. Optimum root growth of most warm season grasses occurs within the range of 24 - 29°C.
Root formations at temperatures below optimum are much slower and tend to be shorter and less branched. Therefore, renovations performed too early in spring on a warm season lawn will extend the recovery period and thereby increase the possibility of an infection over such time.
To overplant successfully, adequate water must be available from the time of overplanting through completion of root development. Newly over planted areas should not dry out completely once overplanting has been completed.
Initially, maintain a constantly moist soil profile with frequent watering of short duration. As newly planted stolons begin growth, the watering frequency is decreased, with watering duration increased to encourage deep rooting.
Once the new desirable species has been grown in, regimes can be implemented to selectively remove the previous desirable species if required.
In some cases, existing lawn areas are in such poor condition or the physical soil conditions are so unsuitable for supporting lawn growth that it is necessary to go through a process of completely re-establishing the lawn area.
This method of lawn improvement is also necessary when the desirable lawn species are not suitable and should be replaced. You can find more detailed information about replacing your lawn in our Guide to Lawn Replacement.
Lawn Care Programs
As you can see, getting the best out of your lawn requires a few important steps that once followed, give you great results. To ensure you get the best from your lawn, LawnPride have developed a range of Lawn Care Programs for the popular turf varieties commonly used for Aussie lawns.
You can also contact our support team at firstname.lastname@example.org where we can answer your questions and help you to have the best lawn in the street!