Lawns and Ground Cover
Lawns and Ground Cover
No horticultural pleasure is greater than to see a splendid British lawn again, having been abroad on however exotic a holiday. This is something that we can do really well. So much indeed is a lawn considered to be an inevitable ingredient ofscene, that lawns are attempted in areas that are either patently unsuitable or completely unnecessary. People even have lawns when the grass is for them an exact preliminary to purgatory.
It is wise therefore to ask several questions. What is a lawn for? Do we want one? Why? How is it to be used? How much effort am I willing to expend upon it? And so on. In so many cases the lawn (or ‘bit of grass’ as it might be more honestly called) is just that area of space which is not wanted for actual cultivation. Unfortunately to turn the bit of grass into a lawn is possibly an even more laboursome occupation.
These remarks, however, are not made to ‘knock’ lawns; on the contrary they are chosen to encourage good lawns in the right places. In ourfew large garden scenes without grass look even remotely satisfactory. Lawns are, after all, that part of a garden which link our plot most obviously with the ‘natural’ world of the English countryside. The reason why the great landscapers of the i8th century were able to incorporate the utter foreignness of Palladian buildings into the shires was their insistence upon a lack of visual division between garden and park. Both were countryside or, conversely, the country was seen for the first time as wholly garden. And that garden was, basically trees set in grass.
Lawns in Small Gardens
On a smaller scale our flower and shrub borders rising from grass present in essence a similar picture. Other plants both set off and are set off by the grass. The smaller the scale, however, the more impeccable the grass needs to be; the more perfect the lawn. This is something of a paradox, because lawn is also access to the borders: the smaller its extent the bigger the wear upon it and the more difficult to maintain visual perfection. This is the point at which the question ‘to grass or not to grass?’ becomes vital.
Small front gardens, so often seen as a patch of tired grass with a 60cm (2 ft) border on all sides must give the negative answer. So too a shady town garden with high walls and trees. It is so often forgotten that ‘lawn’ is not a plant species but a plant community. It comprises of a number of species ofchosen for their ability to withstand constant cutting which mat together to form a tight sward. All plant communities (especially contrived ones) are continually being attacked by other plant species trying to find a place in the sun for themselves.
If they succeed they become part of that community at the expense of one or several of the original members. The direct analogy with lawns and lawn weeds is clear.
With such basic biological pressures accepted it becomes easier to answer the questions posed. If a lawn is required in a small garden it must not receive much wear so through traffic must be catered for. Grassless than 2m (6ft) wide are likely to turn to mud at some stage during the year; further wear compounds the problem. Lawn expected to take children’s games cannot be a perfect sward. No matter — a garden is for use — but the seed mixture must be chosen with this in mind. In larger gardens or a situation only some of the grass needs to be ‘lawn’. Rather as the great I 8th century gardens divided at the ha-ha it is sensible to divide at the place where the cylinder lawn mower gives way to the twice or thrice a year rotary cut with lawn paths through it. Garden giving way to or trees and shrubs in grass is the idea.
And here comes the opportunity of working with, rather than against, the biological pressures of competition. With infrequent mowing a number of fine plants can be introduced to make such a position of great beauty. Bulbs, from Januaryto November colchicums, will succeed. Broad-leaved such as lupins, ox-eye daisies, aquilegias will happily co-exist. This is returning, in fact, to natural meadow: grass studded with flowers where daisies, buttercups and even a dandelion or two are part of the mille fiori scene, not cause for shame.
A continuation of this process of acceptance of broad-leaved species in grass is to reverse the coin and see the broad-leaved as the basic ground cover. Grasses then become the interloping weeds. Lawns of other-than-grass are attempted but are seldom a full success— only grasses have the ability to grow continually from the base of their leaves and hence present a green top. Chamomile, thymes, cotula and sagina have occasional adherents but are best considered as interesting ground-carpeting species rather than alternative lawn makers.
Accepting this, the range of plants to use to cover ground to avoid bare patches (soil in the garden is, as has been said, a medium for growing beautiful or useful plants in, not an aesthetic experience in its own right), to reduce weeding, to furnish ground level texture is enormous. Several excellent websites on this subject alone are available. Suffice it to say here that admirable species can be chosen for all sites and conditions to help to ‘fully furnish’ the garden scene.
Ground cover plants fulfil one very particular and necessary role: they bring that desirable cohesion which links isolated beds, shrubs and trees. These then grow up from complementary textures and colours rather than from bare earth. It should not be believed that ground cover species are entirely labour-free: they are not though they are labour-saving. But the difference in effect when this method is used, instead of the dead hand of herbicides to avoid weeding, is enormous.
There are two particular considerations to take into account. Is the ground cover the dominant plant or community of plants or is it to be the lowest level in an artificial reproduction of natural plant stratification. Both roles are important but clearly the plant species chosen will be very different to cope with the full exposure likely to occur in the former case.
Good lawns demand good treatment and where this is difficult to supply the alternative ground cover role comes in. Banks on falling sites or those made when cutting in aare frequent examples. Solid planting here both holds the soil and reduces maintenance. The scale of the area to be covered, the type of soil, climate and will all—as with any other planting problem—combine to determine the plants chosen. If the site is not too large a single species can be very effective: Hypericum calycinum the lovely Rose of Sharon, is fine in full sun or half shade but as it ramps about it is best isolated by grass above and below; any suckers appearing there are just mowed out. Many of the low Mediterranean shrubs, lavenders and santolinas and so on are suitable, too, for hot dry banks. In shade, ivies are an excellent choice with variegated forms being particularly attractive.
On a larger scale cascading plants such as Rosa x paulii and ‘Max Graf’, Cotoneaster microphylla or C. salicifolia ‘Repens’ andjuniper Juniperus communis ‘Depressa Aurea’ and J.c. Wiltonif are but some of the numerous possibilities.
Ground cover must also be considered for normal ornamental areas. This is the stratification role. Trees will have shrubs underneath, shrubs herbaceous plants, andand ferns inhabit the lowest level. In the wild, whole quantities of species, often very beautiful plants, have become specially adapted to succeed in such situations. These are the plants to look for. Even under roses, which are traditionally kept in isolation, small ground cover plants, pansies and violas, and polyanthus can add to the garden scene offering flower when the roses themselves are still bare and foliage to mute their summer colour. Only one word of warning is necessary. Some very valuable ground cover plants, which are ideal for large sites, are dangerously invasive in if not kept under control. Lamiastrum galeobdolon and the bigger periwinkles are examples of these. Treat them with care; if not rigorously thinned out twice a year they will clamber into the lower branches of large shrubs, while the positions of smaller ones are noted by smooth mounds of the ground cover, not unattractive but not intentional either.
If a large area is to be planted with any of the naturally self-species — and most indeed have this ability and is why they do their job so well — it is worthwhile to plan at least a year in advance by buying a relatively small number of stock plants, lining them out in a convenient unused spot and encouraging layers by pegging down the horizontal shoots as they appear. In this way a considerable number of plants are cheaply raised and, just as important, they are on the spot to be moved to their permanent site when they are needed. Such forethought can save a lot of money as well as being immensely satisfying.