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FAQ

FAQ's


Grass-free lawns are a bit different from traditional grass lawns. This inevitably raises a few questions that I have tried to answer here.
Can it be walked on?

Yes. A little bit of walking can actually help.

‘Walking the chamomile’ was a technique used in the C15th to release fragrance, to help keep chamomile lawns low and in contact with the soil. This helps the stolons root. The same idea applies to the grass-free lawn. Walking, even if it’s only during mowing, helps keep the plants pressed down and can influence their growth pattern (Thigmomorphogenesis). Many of the plant species used e.g. daisies, clover, buttercups etc, can already be found in lawns that are walked upon. However, a grass-free lawn is not intended to be a sports or daily usage type lawn.



Why mow it?

To induce cyclical stress. Tall plants shade-out (stress) low growing plants. Mowing (stress) reduces the size of taller growing plants. A cycle of repeated stress constantly changes which group of plants has the advantage at any one time.

Technically: when a plant is mown it immediately stops growing and there is an imbalance between the top growth and the root growth. There is more root area than the top growth now needs. In some plants the roots shrink, releasing carbohydrates that are used to repair the damage. The plant ceases growth while damage is repaired. Only once the damage is repaired does the now reduced size plant begin to grow again.
Low growing plants that avoided the mowers blade continue to grow during this period, often benefiting from the increased light levels. When tall growing plants and smaller plants are cyclically mown in a diverse sward they can coexist in a way that would not be possible without mowing.


Mowing



How often do you mow it?

It will vary on the composition of the sward and how quickly it achieves a height that prompts mowing. (Guideline: Maximum height before mowing should not really exceed 9cm or 3.5 inches). Roughly expect between 3-9 times per year. That’s 2/3rd’s less than the 20-30+ times for a conventional grass lawn and can mean up to a 3/5th reduction in CO2 emissions.

Mowing height should be just above the low growing plants. This is dependent on the growth habits of the plants used, but is usually at about 4 to 5cm (approximately an inch and a half to just under two inches). The higher the setting the more the cut will favour quicker regeneration in taller growing species. Lower settings risk scalping the lawn.
[Note August 2013: I have amended the recommended average cut height slightly upwards in light of a more complete statistical analysis of my data.]


Won’t mowing cut off all the flowers?

Yes. In a mix of dead heading (and an Addams Family favourite) 'live heading', you cut off hundreds of flowers to allow for hundreds more.

If there is no mowing, taller and faster growing plants will come to dominate, and the lawn will become a meadow. It usually takes about three weeks for the lawn recover and have new flowers.



How often do you need to water it?

All the trial lawns were not watered, apart from two through waterings when they were laid. Experience with newly laid lawns indicates that lawns may require watering as necessary during the first month until the plants have established. Common sense suggests that in extended periods of drought that grass-free lawns will require watering, but to date they show aesthetic drought tolerance, staying greener for longer than turf lawns.



How often do you feed/fertilise it?

There is no need to fertilise ground based grass-free lawns.

Experiments indicated that fertilising favours nitrophilous plants (nitrogen lovers). Fertilised lawns only produced significantly more flowers in the first year. Second year fertilisation produced no significant difference in flower numbers and plant species diversity in lawns had been reduced. Grass-free lawns are best left unfertilized since they will usually include legumes (nitrogen producing plants) such as clover and trefoil.



Do you need to use fungicides/pesticides?

No.

This has not been necessary in any of the trial swards. Slugs have been the only notable pest (and only in the wet dull summer of 2012) – they eat the flowers and young seedlings. This is effectively addressed with slug specific nematodes. Recent research has shown that highly diverse plant communities tend to suffer less from slug damage.



What plants should be used?

Climatically tolerant species are essential. Start with clonal perennial forbs (plants that can spread without using seed, live longer than two years and are soft stemmed) and then add species that can tolerate mowing and the local conditions.

Plants must survive through a typical British summer as well as a typical British winter (RHS Hardiness rating H4). Ornamental cultivars of British natives are a good choice for the UK, e.g. red flowered daisies (Bellis), white flowered buttercups (Ranunculus), bronze leaved bugle (Ajuga) etc.
Using unusual coloured flowers and leaves make the sward visually interesting. Many leaf colours are especially attractive after mowing when there are no flowers and in autumn when flower number drops.

Just because..


How long will it flower for?

That depends on the plants used and inevitably the weather, but up to nine months of the year is realistic. Some of the trial lawns have had flowers (daisies) for twelve months.



Where can I get one?

The construct is currently in development as a commission-only product.
Organisations or individuals thinking of installing a grass-free tapestry lawn please use the Contact form and provide a brief outline including an estimate of the size of the lawn and the immediate local conditions e.g. E, Anglia, clay soil, sunny spot. (Currently this applies to the UK only).

There is as yet no simple seed mix that has proved completely suitable or reliable. Research in this area is on-going. The construct currently uses a mix of plants laid out in a mosaic pattern. These blend together and create a tightly knit sward that is surprisingly resilient and quite possibly synergistic.

An estimate of a general retail cost is currently under review with plant producers. From a purely practical viewpoint the grass-free lawn will produce a unique outcome in each situation and will be a product with its components grown especially to order. It is therefore likely to be some time before an off-the-shelf or economy version is available.



Where can I see one?

• Two new lawns at Reading University, Palmer Building and Old Whiteknights House, Reading and in the walled garden bee friendly zone.
• 200 square metre example at Avondale Park, Notting Hill, Kensington & Chelsea, London, W11.
In development: RHS Wisley, Surrey, Oakham School, Rutland, The Old Bowling Green, Dorcester.



Bee on fox & cubs



Is it good for bees and butterflies?

Absolutely yes.

A pollinator study was carried out last year (2013). Comparisons of visits made by pollinators (hoverflies, bees and butterflies) to an ornamental grass-free lawn, to traditional turf and a commercially available ‘flower lawn’ (a mix of grasses and wildflowers), showed grass-free lawns were visited by four times as many pollinator species than turf and almost twice as many as flower lawns.
The frequency of visits was also greatest on grass-free lawns, with over one hundred visits for every twelve recorded on flower lawns and one on turf.

Since frequently mown grass lawns are a poor source of pollen and nectar, and grass-free lawns are de-facto flower lawns, opportunities for pollinators are greatly increased.



Is it good for birds?

A study of insects in grass-free and turf lawns has shown that in grass-free lawns a greater diversity of invertebrate species exist and in significantly greater numbers than that found in a traditional grass lawn. This increases the potential food resources for insect eating predators such as garden birds and small mammals.

Avondale Blackbird




How long will it last?

The flower lawn is perennial. It will certainly survive beyond the strict definition of perennial - two years. The oldest trial lawn at Reading is four years old and is still looking quite beautiful. If it needs refreshing – a spot of lawn gardening will do the job. The need for mowing appears to lessen as the lawn becomes older. The Reading lawns now get mown 3-4 times a year and have a richly diverse internal structure.



Won’t it be invaded by grasses and weeds?

Nothing can stop a dandelion seed or other wind-blown seeds (including grasses) from reaching the lawn. A spot of lawn gardening should sorts this out. It is important to remove grasses when they are spotted. This is most easily done in spring when the grasses have become taller than the lawn and are easily spotted.

Remember: It is the absence of grass that allows the grass-free lawn to exist.

A ‘weed’ is generally thought of as the wrong plant in the wrong place. That is often a personal or subjective view point. A daisy can be a weed in a grass lawn, but not in a grass-free lawn.



Can you use gramicides (specific grass killing chemicals)?

This has not yet been tested on grass-free lawns, however a number of gramicides are currently available that offer control of grasses.



Do you have to rake or aerate or de-moss the lawn?

Raking is not possible; the internal structure of the lawn prevents this and would make it a destructive practice. Aerating has not been necessary since it is a light footfall construct and the plants used (forbs) have a different root structure to grasses. As yet, moss has not been seen to develop spontaneously in grass-free lawns.

No raking


What type of mower should be used?

No specific type can be recommended – any should do, so long as they can collect the clippings.

It is necessary to remove the clippings to prevent a blanket of clippings forming on the lawn and reducing access to light.



How to deal with clippings.

The clippings should be treated in the same way as grass clippings when composting (i.e. mixed with high carbon content material), since they are soft and green, and tend to form a sludge if left unmixed.


Scattering



Is this some sort of 'wildflower turf' or something I can create with a wildflower only seed mixture?

Not at this moment in time.

Wildflower turf contains grasses, and pure wildflower seed mixes or pure wildflower 'turf', although they don't contain grasses, are also started by mixed seed. Using current wildflower turf or wildflower seed mixes does not produce a grass-free lawn in the same way.

All of the species (but not some of the cultivars) used in a grass-free lawn as developed at the University of Reading can be grown from seed, but sometimes seed is not actually commercially available and propagation is from cuttings only.

At this moment in time the mosaic style grass-free lawn is created almost exclusively by using plants.

It should also be noted that many of the species and particularly the meadow phenotypes that are currently used in many wildflower-only seed mixes are not suitable for a grass-free lawn, they are selected forms for use in taller growing meadows.
Phenotypes are specific growth forms e.g. tall growing types or dwarf growing types of the same species. Many meadow phenotypes (tall types) do not respond well to mowing more than once or twice a year.

By some incredible temporal coincidence, there are suddenly lawn and seed companies claiming to produce seed mixes that will produce a University of Reading style grass-free lawn using a simple aromatic/pollinator friendly or wildflower seed mix.
These wildflower-only seed mixes contain species and phenotypes that will not perform in the same way as plants identified by the research as being suitable for grass-free lawns.



Can I get a plant list?

100 Years


Due to the enormous amount of interest at the RHS Chelsea Flower Show in 2013 and repeated requests, here is a list of the plant genera that were used to create the show lawns.

Acaena, Achillea, Ajuga, Anthyllis, Argentina, Bellis, Campanula, Cardamine, Chamaemelum, Chrysanthemum, Dianthus, Erodium, Fragaria, Geranium, Geum, Glechoma, Houstonia, Leontodon, Leptinella, Lobelia, Lotus, Lysimachia, Mazus, Mentha, Nierembergia, Oxalis, Parachetus, Phylla, Pilosella, Polygala, Potentilla, Primula, Prunella, Ranunculus, Sagina, Taraxacum, Thymus, Trifolium, Veronica, Viola

Some of the cultivars used were specifically bred as part of the PhD research project here at Reading University, especially for the grass-free lawn construct; most specifically the red leaved and red flowered clovers (Trifolium repens) and the golden leaved yarrow (Achillea millefolium).

T.repens floral variants


At this moment in time it is safe to say that many clonal perennial forbs make an ideal base for a grass-free lawn and plants that can survive the mower can be added in light of local conditions and aesthetic requirements. British natives and many of their cultivars are ideally suited to the British climate, although many do not tolerate repeated mowing.
Be aware that there are many cultivars and forms (phenotypes) that have been bred for circumstances and situations outside gardens and urban environments e.g. for green mulches, as fodder crops and for use in pastures, and that some naturally occurring variants can be particularly vigorous in highly fertile urban situations.

Most of the plants used in grass-free lawns can be found in garden centres, plant nurseries or obtained from seed houses. However, it is not yet possible to recommend specific companies, organisations or sources.

A word of advice: NOT ALL OF THE PLANT SPECIES YOU FIRST USE WILL SURVIVE.
Survival is dependent on local conditions - moisture availability, soil pH, light levels, local temperatures etc, and the other plants used in the sward. Expect to lose a few and to gain a few unexpected ones.
The ones that like your lawn space will likely thrive and look beautiful in a mix quite unique to your conditions. No other lawn will look exactly the same.

Most of all: remember to mow and after you have laid your lawn, to enjoy all the hard work you don't have to do!



What will happen in Winter?

The video link on the LINKS pages show the largest University of Reading trial lawn through three years of evolution. This (apart from the occasionally annoyingly foggy lens) clearly shows two winters; including what has been described as the worst British winter for 100 years. Air temperatures above the lawn were recorded at -10.5C (13.1F). The ground temperature was likely to have been lower still. (RHS Hardiness Rating H5)

January lawn


The herbaceous plants (plants that completely die back in winter) behaved as expected and vanished from sight. Since the lawn had developed into a thick sward that includes many non or semi-herbaceous species, this was not a notable problem in aesthetics.
Some of the plant leaves naturally changed colour during cold spells, and red and reddish brown tones were not uncommon. There were also autumnal yellows and golds as the herbaceous plants withered away for the winter. Bare patches were fortunately rare and small, but could be found if seriously looked for.

Lobelia and thyme


How many plant species should I use?

A specific minimum plant species number is difficult to identify with any meaningful accuracy since every site is individual. Use as many species as possible - ideally a minimum of 12+. The Avondale Park lawn used over sixty species and cultivars and the Chelsea show lawns over seventy.

The more species included in the lawn, the less likely it is that any one species will come to dominate it. Unlike traditional lawn monocultures the grass-free lawn is a polyculture created from as many different mowing tolerant species as possible. The high level of plant diversity is a distinct feature of the grass-free lawn.
Grass-free lawns are dynamic, and it is possible to observe over time that the plants move about and thrive at different times of the year and in different years. Grass lawns are dynamic in a similar way, but since only grasses are used the dynamism is hidden - it is difficult to spot a grass plant moving around in the grass!

The more species used, the more options you have to choose for plants that flower at different times of the year, have different leaf and flower colours, are suitable for local conditions, act as winter cover and attract pollinators. Remember: NOT ALL OF THE SPECIES FIRST USED WILL SURVIVE, so the more species used, the less impact a loss will have.



How do I prepare the ground for a grass-free lawn?

The ground should be free of all other plants, particularly any grass.

Grass can be removed by a variety of methods. There are turf cutters that can cut and lift existing lawns. Spades can be used (from experience this may involve some surprisingly strenuous muscle work and an aching back), as can biodegradable glyphosate weed killer while it is still licensed for home use. Covering lawns with a light-proof covering is also a possible method.

The lawns at Reading had the top 6cm of soil removed before planting. This was to remove the fertile topsoil and expose the less fertile subsoil. In the process it also removed the topsoil seed bank and provided a ready-made space in which to place the plants used to make the lawn.

Soil removal was impractical in Avondale Park for a number of reasons. The area was rotovated to loosen the soil and cut any deep rooted perennial weeds such as thistles. Trays of plants were then laid on top of the soil as shown in the planting video.



Is it pet proof?

Experiments on the lawn with pets and their associated by-products have not been carried out. This is not exactly a well funded area of research. Common sense suggests that if a pet is able to damage a robust grass lawn, then it is highly likely to damage a grass-free one.



What about shade?

There have been no specific shade experiments. The experimental plots all receive shade at some time during the day, as does the Avondale Park lawn. This is where a little bit of plant knowledge will come in handy when selecting the species that you first use.

Plants that like constant full sun will likely not do well in deep shade. The opposite is also likely to hold true. Having said that, I have noticed that plants that like shade in hotter and sunnier regions of the world can often happily take what we British think of as strong sun and tend to sulk in our cooler shade.

Shady lawn


This is where a bit of risky experimentation can help. You know you will lose some species - so dare to throw caution to the wind and just try a few that you think are borderline non-starters. You might be surprised, I certainly have been.

Since for the most part grasses tend to be sun loving plants - (it's one of the reasons why they do so well in open lawn and parkland spaces) they tend to struggle in shade.

If you first select plants such as woodland edge plants e.g. Bugle - (Ajuga reptans) that prefer semi-shade, it is quite possible that they will thrive in areas that grasses struggle in.
Remember to use AS MANY DIFFERENT SPECIES AS POSSIBLE to ensure that the majority will continue happily in the shadier spots of your lawn.



What about using Alpines?

If you seek to have an Alpine Lawn a good book to refer to is Anne Ashberry's book, 'Alpine Lawns - with Some Account of the Special Use of Carpeting and Crevace Plants.'

The grass-free lawn is not an Alpine lawn. True alpine plants originate in areas that do not have the winter wet soil that distinguishes the British winter climate. Winter moisture is generally locked up as snow in alpine regions. True alpines can suffer from winter root rot in the UK unless they have very sharp drainage.

There are however many plant species labelled as 'Alpines' simply because they are small in stature, rather than because they specifically originate from high alpine regions. An example of this is Blue Moneywort (Lindernia grandiflora). Its origins are in SE USA (that famous alpine region of Florida!) and it can be tender if unprotected. It is often labelled in garden centres as being an Alpine.

Plants that are labelled as 'Alpines' but actually grow well in ordinary garden soil are a much better choice. I might suggest that you go and stress-out your local garden centre staff with questions about the real and actual suitability (from direct experience perhaps) of 'Alpine' plants for your local soil, but I wouldn't be so cruel.



Tapestry lawns are a research based selection of the native and non-native plants and plant forms, variants and cultivars that are suitable for use in grass-free lawns.
Tapestry lawn™ is a trademark of Dr Lionel S Smith.
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