Beth Chatto's Gravel Garden
'For some years I had dreamt of making my Gravel Garden, with plants adapted to the prevailing conditions, instead of watching mown grass turn biscuit-brown for weeks every summer. I hoped to see which plants would survive without hosepipe irrigation and was prepared to lose some of the many new introductions not yet sufficiently tested for summer drought or winter cold and damp. I would replace these with other, more resistant plants. I hoped to teach myself and possibly help visitors to make and maintain some kind of decorative garden without irrigation.'
-Beth Chatto
When Beth purchased a piece of land adjacent to the garden to create a larger carpark to accommodate her growing number of visitors, she knew the ¾ acre former carpark would be the ideal spot to site her Gravel Garden. The area offered extreme conditions; 6m/20ft depth of poor, thin soil, overlying sand and gravel, full sun and little annual rainfall. She carefully chose plants that would be able to not only survive but thrive in these far from ideal conditions. Beth planned to treat the Gravel Garden as a horticultural experiment; to see if it was possible to create an unirrigated garden in one of the driest parts of the country, with an average rainfall of only 50cm/20in.
As with all areas of Beth’s Garden, the planting was determined by existing soil conditions and climate. The plants selected for the Gravel Garden naturally grow in poor, free-draining soil in climates that offer mild winters and low annual rainfall, so are perfectly adapted to cope and thrive in the prevailing conditions. Beth credits her understanding of plant needs to her husband Andrew’s life-long study of the native habitat of garden plants. Andrew’s research, recognising the link between plants and their natural environments, can be accessed here.
'It was in the High Alps above the village-too high, we fervently hope, to be spoilt by modern conveniences made for leisure seekers- that I was introduced to Nature’s natural gardens, just below the permanent snowline. I saw for the first time that, whatever the site, whether stony slopes exposed and windswept above high mountain passes, north-facing slopes or damp hollows and streamsides, each had its own distinct group of plants, adapted to differing situations.'
-Beth Chatto
Beth took inspiration for the design of the Gravel Garden from a partially dried-up river bed she encountered whilst on a trip to New Zealand with Christopher Lloyd in 1989.
The creation of Beth's Gravel Garden
Work began in the autumn of 1991. A subsoiler pulled behind a tractor, was used to break up the heavily compacted soil to a depth of 60cm, allowing rain and roots to penetrate. The whole area was then ploughed, turning in the existing grass. In January 1992 a borrowed farm roller was used to lightly flatten the furrows so Beth could lay the initial design. The position of the island beds was determined by laying out hose pipes on the ground until Beth achieved the desired effect. She carefully considered the flow of the meandering path throughout the garden and the overall appearance of the separate beds to one another.
The surface of the beds were then covered with homemade compost, spent mushroom compost and bonfire waste to help conserve moisture. This was then incorporated to a depth of two spits to help provide nourishment for the first few months, offering plants the best start.
Once the soil had settled by March 1992, the paths were gravelled and Beth was able to begin planting. As plants were going to be unirrigated, it was essential to give them the best start by dunking them in water to ensure the rootball was completely saturated and no more air bubbles were released. Plants were placed out and planted, with each plant being thoroughly watered in using a hose.
Beth didn’t use a mulch in the first year as she wanted to be able to deal with any inevitable weed seedlings arising from the incorporated compost. Any seedlings that popped up were routinely hoed avoiding any further weeds setting seed.
By the spring of 1993, the beds were ready to be mulched with local 10mm gravel to retain some of the moisture that was still in the soil. It was applied to a depth of approx. 3-5cm taking care to avoid smothering low growing plants.
The drought tolerance of the planting was tested during the summers of 1995 and 1997 when the garden was subjected to abnormally high temperatures and minimal rainfall. The soil beneath the mulches dried out and the plants began to show signs of stress. Seeing the plants wilting, Beth was very tempted to give up on her experiment and reach for the garden hose. Nursery Manager, David Ward persuaded Beth to continue with the experiment and see how the plants would respond. As soon as cooler weather and penetrating rain arrived, the plants recovered and sent out fresh new growth.
Gravel Garden Planting & Maintenance Today
Over the years, the planting in the Gravel Garden has been tweaked to make sure only plants that are truly drought-tolerant remain. The original planting, for example, included a range of achillea, but over the years they have petered out, struggling to cope with the extremely poor and dry conditions. Some plants have been lost or removed, but many have also been added over the years. Plants such as Stipa barbata, Hylotelephium ‘Red Cauli’ and Romneya coulteri are later additions to the palette of plants on display.
Over the years, the soil preparation for new planting has been adapted slightly. When an area of the Gravel Garden is rejuvenated now, the Garden Team try to improve the soil just enough to give plants the best start but not increase the nutrient value of the soil too much. This encourages lush growth at the start of the growing season and, come June or July when the really hot weather arrives, plants will wilt and struggle.
The area is initially dug over to relieve compaction and remove roots. A layer of soil improver is added to the area to a depth of approximately 2cm and then incorporated into the existing soil beneath by forking in. The soil improver used is composted council green waste which is low in nutrients (great for the plants which thrive on poor soil). The incorporation of organic matter helps to build up the soil structure, improving its water holding capacity.
When planting, plants are dunked in water until saturated as before, but before placing in the ground, much of the richer potting compost that the plants were grown in, is removed from the roots to encourage roots to venture out of the planting hole.
I think the gardeners would all agree that the Gravel Garden is the most labour-intensive part of the garden. The warm gravel provides the perfect germination conditions for seeds. Many of the perennial, biennial and annual plants are left to self-seed, allowing them to naturally spread into empty spaces. By allowing plants to migrate from one area to another, the scene is forever changing. The growth of plants left to develop in the spot they have germinated should be stronger as they haven’t been checked by transplanting. Many of these seedlings however will be meticulously ‘edited’ out and the position of any remaining seedlings is carefully considered. A good example would be Verbascum bombyciferum; a rash of hundreds of seedlings will be reduced to only one or two seedlings which will be left to reach maturity. The rosettes can reach up to 1m in circumference so their place in a border must be carefully considered. Do they have enough space to reach their final size? Are they growing too close to existing planting that may be crowded out? Will their final height look out of place among the other plants? Gardener Sally has written a blog about self-seeders and ‘pioneer’ plants which you can read here.
If plants struggle during the summer months and begin to wilt, we may cut them back by half to reduce the stress on the plant. Come early autumn (when we typically receive more rain), the plants begin to perk up again and put on fresh growth. The spring and summer of 2018 were extremely hot and dry and the Gravel Garden endured over 50 days without rain, really putting the plants to the test! Head Gardener Åsa explains HERE how the Garden Team mitigated the effects.
...compared to August 2021 when we received more rainfall.
'The point I need to stress is that copies of my Gravel Garden will not necessarily be successful or suitable if the principles underlying my planting designs are not understood. When visitors to my garden tell me they have attempted to make a gravel garden but the plants don’t look or behave as they do in mine, they wonder what they have done wrong. I ask, What type of soil do you have? Very good, they reply. The amount of rainfall? Twice what we have here, they tell me. I laugh, and say if I had good loam and adequate rainfall I would not be growing drought-tolerant plants but would grow well-loved plants like delphinium, phlox and aster, and many more desirable species which thrive in such conditions.'
-Beth Chatto
Weed membrane and fertiliser
We often get asked if we use weed membrane under the gravel mulch and visitors are very surprised when we say no! By not having a barrier, we have access to any perennial weeds and can dig them out. If we are unable to remove the whole root because of shrub or tree roots, we will continue to dig out what we can reach, eventually weakening the plant and reducing its vigour. A weed membrane would be no use against annual weeds which freely seed into the gravel mulch on top and would make weeding them out much harder. The gravel mulch occasionally wears thin in some areas, especially along the path edges. If a membrane was underneath, it would look very unsightly when this happens.
We also often get asked if we fertilise the plants in the Gravel Garden as the soil is so poor. The answer again is no and leads back to the importance of soil preparation. Any fertilising that plants receive would come from the addition of organic matter incorporated in the soil prior to planting. By choosing plants that are suited to the soil conditions and by preparing the soil to the needs of the plants, there is no need to feed with additional fertilisers.
'Most of the plants I have chosen for this area do not require extra feeding and would grow out of character if overnourished and therefore would be more likely to collapse when suddenly hit by high temperatures without adequate moisture to sustain them.'
'These plants are not cosseted by man. Nature provides for them. They are adapted to a sparse diet. Because our ‘soil’ is initially so devoid of nourishment we aim, as I have said, to give fresh introductions a fair start, but after that, they must fend for themselves. Most of them do.'
-Beth Chatto
By Leanne Crozier- Social Content Creator
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