Friday, 28 November 2008
Tulips are often considered ephemeral in the garden, and it's true that many hybrid tulips decline in vigour after the first year. Species tulips, however, are reliable year upon year, often naturalising and setting seed to produce drifts of flowers that actually improve over the years.
Species tulips tend to be smaller and less showy than their hybrid counterparts but they are equally heart stopping. The flowering season begins on early March just as the garden is waking up from winter, but there are varieties that bloom in succession all the way through until the end of May. From the creamy drifts to Tulipa turkestaica to be the lipstick-red of Tulipa fosteriana, it really is worth making room form these little beauties in your garden.
As a general rule, good drainage is essential for all tulips. Although they love to be watered during their growing season, most species tulips prefer dry soil over the summer months. Rock gardens have typically been the best place to grow species tulips because they emulate their natural habitat in the wild, but they are not the only situation in which these diminutive gems will flourish.
Pots and containers
Tulipa greigii starts flowering in March. The dwarf flowering habit and large decorative leaves make for stunning displays in window boxes and containers. Try combining Tulipa greigii 'Red Riding Hood' with winter pansies and trailing ivy for a late-winter show stopper. Try also T. humilis 'Persian Pearl' and T. kauffmanniana 'Heart's Delight'
Tulipa acuminta is an usual and exotic-looking tulip with needle like pointed petals of red and yellow. It is a surpise hit in clay soil, flowering in May, and is excellent for cut-flower arrangements.
Low-growing and early-flowering, Tulipa humilis is equally happy in a rock garden, a raised bed, sunny border or a pot. It has delicate, blade-like leaves, and is available in a wide range of colours.
Tulipa turkestanica is one of the easiest species tulips to grow, and deserving of a place in almost every garden. The elegant creamy-white flowers have a rich yello centre, and really brighten up the winter garden. These tulips will spread gradually and reliably to form dense patches of small starry flowers.
Tulipa sprengeri is the exception to the rule: flowering in late May and early June, it actually prefers slightly moist soil - and even a bit of shade. try including it in woodland-edge planting schemes, or use it to underplant deciduous trees and shrubs. Don't be put off by its price: Tulipa sprengeri sets seed widely and will soon become an established accent in the garden.
With its sturdy stems, broad leaves and huge bright red flower which can be 15cm across when fully open - Tulipa fosteriana is one of the most popular species tulips. it adapts to a wide variety of soils and situation, relishes neglect and reliable each year.
Wednesday, 19 November 2008
We are used to pairing clematis with roses, but there are hundreds of other combinations to be explored. Many plants offer limited interest for long periods of the year, so why not extend the season by partnering established trees and shrubs with a clematis?
Buddleias are great with the lavender-blue Clematis ‘Arabella’ or the dramatic dark-purple ‘Miranda’. Both cultivars flower non-stop from spring to late summer and will actually benefit from any hard pruning your buddleia requires to keep it in check. Other silver-leaved shrubs such as Garrya elliptica gain from an association with Clematis viticella ‘Palette’, which has delicate purple-veined flowers fading to white at the centre.
Monday, 3 November 2008
The main borders combine traditional herbaceous perennials with swaths of ornamental grasses and plenty of roses. I have inherited my mother’s love of old-fashioned roses, so I squeeze in as many as I can. I am particularly interested in designing planting with the relaxed painterly look of a traditional herbaceous border without the intensive maintenance – and this is where I try out my ideas to see what really works.....
This year, we have been attacked by slugs in their thousands and I have taken the opportunity to experiment with aromatic substitutes for some of my favourite border perennials. As a result, I have discovered a new favourite in Teucrium hircanicum, which has, this year, replaced Salvia nemorosa ‘Schwellenburg’ in the Nottingham borders. I am becoming almost evangelical in my promotion of Agastache. But my best discovery this year is a waste product from the rooibos tea industry, called Fine Naturals, that is brilliant at deterring slugs.
Tuesday, 16 September 2008
Autumn is on the way, and it’s a good time to think about making new beds. More dauntingly, you may have just taken on a whole new garden or an allotment. As you dream longingly of friable loam, your spade invariably hits builders’ rubble, free-draining sand or compacted clay. While there is little choice except to dig out builders’ rubble, there are more options when it comes to the task of enriching the soil. Recycled green waste, animal manure and spent mushroom compost are popular additions, but before you start despairing at the cost of lorryloads of compost, don’t forget the cheapskate’s alternative: green manure.
Green manures or cover crops are an inexpensive way to improve both the structure and nutrient content of your soil. Cultivated primarily to add organic matter to the earth, a green manure crop is usually grown for a specific period (say six weeks, or over winter), and then chopped down and incorporated into the soil. They are a great option when preparing new land for use – forming a green carpet that stops weeds colonising and prevents nutrients from being washed away. Some varieties, such as lupins, fodder radish or alfalfa, even help to give the soil structure because their fibrous tap roots break up the subsoil.
Traditionally, green manures have been used on arable land or allotments, but they are equally useful in gardens. All you need is a packet of seeds, a spade, and patience while they do the hard work for you.
Green manures consist of legumes and non-legumes. Legumes are popular for their ability to fix nitrogen: once the green manure has been dug into the soil, this nitrogen becomes available for future plantings. Non-legume plantings, however, often produce more organic matter. They have a better root system and so are better suited to surviving extreme weather conditions and poor soils. There is a green manure for every ailment: red clover suits sandy soil; field beans and grazing rye are excellent in clay; lupins improve the substructure of the soil; while the best choice for dry soil is alfalfa.
Fast-growing, leafy green manures are often recommended for gardens because they provide the most nutrients when dug into the soil. Just remember, if you are preparing soil to grow vegetables, your green manure should not be closely related to the plants that are to follow. For example, don’t use legumes such as field beans if you are planning to grow runner beans or garden peas afterwards. This reduces the likelihood of disease.
Although many green manures can be sown all year round, it is ideal to sow them in the autumn to overwinter, as vegetable plots are generally empty and people are spending less time in their gardens. Try sowing fast-growing fodder radish or mustard in early September so that it can be incorporated in late October. Alternatively, cut down and chop up the green manure in late October and leave it on the surface as a mulch.
Italian ryegrass and Hungarian grazing rye can also be sown in September because they are very hardy. Leave them growing all winter before being dug in during spring to release nutrients as they rot. If you are growing your green manure on clay soil, however, it’s best to dig it in during autumn. Alfalfa is another good choice for an overwintering green manure. This nitrogen fixer should be dug in during the spring.
Before sowing your green manure, the site should be roughly dug over and weeded. The soil needs to be firmed by lightly treading it down, and then your seeds can be sown in rows about 6in apart, or broadcast and raked in.
All green manures should be dug in while the stems are still soft so that the plant can break down easily. It is a good idea to chop up the green manure and allow it to lie on top of the soil for a few days. It should then be dug in to a depth of about 6in. Your soil should be ready for planting only a couple of weeks after incorporation.
Green manures are often overlooked by gardeners looking for a quick fix, but used wisely, they can play an important and cost-effective role in the establishment and maintenance of a garden.
Hungarian grazing rye. One of the best green manures for winter use. Sow in August/September, or as late as October in the South. A good cover crop to prevent nutrient-leaching. Dig in during the spring.
Field beans. Very hardy, with deep nitrogen-fixing roots. Suitable for overwintering.
Fodder radish. Deep tap root brings up nutrients from the subsoil, and produces plenty of organic matter. Over winter it will gradually die down, making it easy to incorporate into the ground in spring.
UNDERSOWING AND INTERCROPPING
White clover. Low-growing for ground cover and intercropping between rows of vegetables. Use as a living mulch or long-term green manure.
Trefoil. Shade-tolerant and low-growing, so great for undersowing. Sow between March and August and it will stand through the winter into the following season. It does not like acid soil but will tolerate some shade and is suitable for undersowing, for example between rows of sweetcorn. When the corn is cut down, the trefoil will grow to protect the ground over winter.
MULCHING AND WEED CONTROL
Crimson clover. A vigorous, quick-growing clover with wonderful red flowers, which bees love. Sow April-September. Not normally winter-hardy because it dislikes waterlogged and heavy soils.
LONG-TERM GREEN MANURES
Alfalfa. Rich in calcium and the major elements – almost a complete natural fertiliser. It is very deep-rooting – improving substructure and bringing trace elements to the surface. Sow April to July. Can be turned under in the autumn or left to stand through the winter.
Tuesday, 17 June 2008
Everyone loves elegant, architectural bamboo, but choose the right one or you could end up with a jungle...
So which bamboos are invasive and which not? There are two main types, depending on how their rhizomes grow: runners and clump-formers. Runners can be difficult to control as their long underground rhizomes will always try to colonise new areas. They include Sasa, Pleioblastus, Sasaella and Phyllostachys. Clump-forming bamboos tend not to be invasive and include Fargesia, Bambusa and Chusquea.
Although gardeners have worked out how to manage the spread of invasive bamboos, we are just beginning to understand the wide range available. A few years ago, the main trend among garden designers was for black bamboo. With this now established as a firm classic in the planting palette, designers are starting to expand their repertoire of plants. Lime culms (canes) such as Phyllostachys viridiglaucescens are particularly fashionable at the moment.
So why do garden designers love bamboos so much? Partly because they are evergreen, they create strong architectural structure all year round – hugely important in urban gardens. In a small space, they provide volume and drama, and they grow amazingly fast – new shoots can put on 10-15cm a day in the growing season. Yet they don’t block out the light, which means they make great screening plants.
If privacy is your principal concern, think about Phyllostachys nigra, which is very narrow but tall and so doesn’t take up too much space in small gardens. Besides ugly views there’s the issue of ugly noise, and the gentle sound of wind rustling through bamboo can block out both traffic and neighbours even more effectively than a water feature – with the bonus of being much lower maintenance than water. The other great advantage of bamboo is that it can provide strong foliage in a shady garden – Fargesia is particularly good where sunlight is limited.
Those are the basics, but designers will often create sophisticated effects, particularly with the shadows of bamboos – the light foliage creates great dappled effects in sunlight, or dramatic contrast under artificial lighting. In winter, the stems of bamboo can provide a feature in the same way as dogwoods. Try Phyllostachys aureosulcata f. aureocaulis, whose golden yellow stems blush pink in strong sunlight.
So how do you integrate bamboo into a planting scheme? First, look for a variety with plenty of good foliage. Try Phyllostachys bissetii, which is a fresh green even in midwinter, and surround it with flowers as punctuation points.
My favourite bamboo garden, la Bambouseraie in the south of France, can still teach us a thing or two about how to use bamboo in the landscape. Pleioblastus pygmaeus can be clipped to form a low-maintenance hedge, a bit like box, and Sasa forms a wonderful weed-suppressing groundcover. For inspiration closer to home, visit the Bamboo Garden at Kew, the Eden Project in Cornwall or the Bamboo Labyrinth at Alnwick in Northumberland.
CANE MADE PLAIN
Grow in your garden
Select the position for your bamboo carefully. Most bamboos prefer full sun but if you need a bamboo for a shady spot, a Fargesia is ideal.
Some bamboos, as you are probably already aware, are rampant spreaders and so it is important to contain their roots. Line the planting hole to a depth of just over half a metre with paving slabs or a specialist rhizome barrier (available from all good nurseries). Don’t make the mistake of using a pond liner as the roots will easily pierce it. Remember that bamboo roots can arch over low barriers, too, so make sure the top extends at least 3in (8cm) above ground level.
Try: Phyllostachys nigra, Fargesia denudata, Fargesia rufa, Phyllostachys aurea
Grow in pots
Another option when growing invasive bamboo is to grow it in a container of at least 18in (45cm) in diameter. Make sure the pot has good drainage, and keep your bamboo well watered at all times to ensure strong growth.
Try: Phyllostachys nigra, Sasa or Pleioblastus variegatus
FROM ALICE'S ARTICLE IN THE TIMES June 2008
Thursday, 24 April 2008
Over the past 60 years, 95 per cent of our wildflower-rich meadows have been lost, mainly due to changes in farming practice. Creating small areas of wildflowers in your garden not only attracts wildlife and increases biodiversity, but also provides an area of sumptuous beauty. You can create a meadow in your garden with only a few square metres with which to work. The key thing to remember is that wildflowers respond best to hardship and trauma, so impoverished soil is a must.
The first thing to do is reduce the fertility of the soil. This can be achieved by scraping off the topsoil, or by importing a substrate of hard core (builders’ rubble or old broken garden bricks, for example), crushed limestone (available from builders’ merchants) or fine gravel laid on top of a weed-suppressing geotextile. Immediately stop fertilising the area, and either this month or next month sow a wildflower mix that suits your soil type and situation. To make it easier to broadcast your seeds evenly, try mixing them with silver sand. Sow half your seeds lengthways and half widthways, rake in lightly, water thoroughly and leave them to grow. Do not fertilise.
If you are stuck for inspiration regarding which wildflowers to grow, find out which varieties naturally flourish in your area, or use the Postcode Plants Database at www.nhm.ac.uk/science/projects/fff; it generates lists of native plants for any specified postal district in the UK. Where possible, obtain seeds of British origin, grown by wildflower seed companies on their own land. Cut your meadow at the end of the summer, remembering to rake up and remove all debris. Be prepared to manage your meadow in subsequent years by removing any dominant thugs, incorporating further sowings and supplementing with plug plants.
Bear in mind that traditional wildflower meadows can take many years to establish. But for those who don’t have quite that level of patience, there are a couple of cheats and shortcuts available. The first is to sow a Pictorial Meadows seed mix. Developed by Dr Nigel Dunnett at the University of Sheffield, these mixes have been carefully blended from native and non-native hardy annuals to provide a long season of cost-effective and painterly “meadow effect” displays. They overcome many of the problems associated with creating meadows from seed and are perfect for creating flower meadows in the garden. Unlike most wildflower meadows, the success of these mixes is largely down to good ground preparation and good soil fertility. My favourite blend is the annual short mixture, which contains California poppies, larkspur, love-in-a-mist and cornflowers, and which flowers all summer long with glorious intensity.
Or, for an “instant” wildflower meadow, you can buy rolls of pre-seeded felt that you lay just like a carpet. This biodegradable material is the ultimate low-fertility medium and acts as a barrier against pernicious weeds and other more aggressive grasses that would normally stop wildflowers from taking root. The felt also retains moisture, helping the wildflowers establish quickly in the soil below. The British wildflowers in this product have been selected to provide a colourful display and a prolonged flowering period, although you can order a bespoke seed mix if you prefer.
Gardens to visit for inspiration
Naturescape Wild Flower Farm Visitor Centre, Lapwing Meadows, Coach Gap Lane, Langar, Nottinghamshire (01949 860592; www.naturescape.co.uk).
The Wildfowl and Wetlands Trust, Pattinson, Washington, Tyne and Wear (0191-416 5454; www.wwt.org.uk/centre/123/washington.html).
Pictorial Meadows, Manor Lodge, 115 Manor Lane, Sheffield (0114-276 2828; www.pictorialmeadows.co.uk).
Lindum Wildflower Turf, West Grange, Thorganby, York (01904 448675; www.turf.co.uk).
Landlife Wildflowers, National Wildflower Centre, Court Hey Park, Liverpool (0151-737 1819; www.wildflower.org.uk).
Really Wild Flowers, HV Horticulture, Spring Mead, Bedchester, Shaftesbury, Dorset (01747 811778; www.reallywildflowers.co.uk).
With changing weather patterns, designers may need to consider a palette of plants that are able to cope with more than one extreme.
The capricious weather we have been enduring over the last few years has highlighted the need for a new approach to our planting choices. In the past we could identify gardens as 'boggy' or 'dry' with some ease, and then plant them accordingly, but things are becoming less and less predictable. Weather extremes of flood and drought can both occur in the same garden within a short period: often without warning. If we can no longer rely on the accepted weather cycles of previous years, we must take action to adapt our planting designs to cope with the unpredictable impact our volatile weather may have on growing conditions.
In recent years we have all become experts in drought tolerant planting, but for the unpredictable weather challenges ahead we will need to develop a sophisticated arsenal of bimodal plants: that is, plants which can cope with more than one type of weather extreme.
Interestingly, plants that typically grow in moist habitats often survive suprisingly well in drier soils (so long as the soil is reasonably fertile) but the opposite is rarely true. Plants that are adapted to dry conditions often do not cope with flooding and waterlogged soils.
In fact, as a general rule, all grey and silver leaved plants hate flooding. This includes drought tolerant plants such as senecio, buddleja, echinops, eryngium, thyme and lavender. Therefore it is best to avoid using all of these mediterranean plants unless they are in planted in pots or raised beds, or have excellent drainage.
Beech and Cherry trees are known to be particularly vulnerable to flooding, so a sensible stormscaping choice would be to substitute them with storm proof alternatives that offer similar visual characteristics. Why not try using hornbeam as an alternative to beech for trees and hedges, as this tolerates wind, drought and flooding. As an alternative to the cherry tree, why not plant amelanchier: whose clouds of spring blossom are unrivalled in my garden. Amelanchiers also provide exquisite autumn colour – and if planted as a multi-stem specimen can act as a mini windbreak. An alternative source of storm proof autumn colour can be found in the form of the vibrantly coloured Liquidamber styraciflua or Acer saccharinum. – both of which tolerate extreme of flood and drought with some ease.
Few trees, except the large swamp Cyprus (taxodium distichum) can tolerate more than one month of submersion during the growing season but as a general rule, broad-leaved trees tolerate flooding better than conifer trees. Try alder (Alnus) river birch (Betula nigra) hornbeam (carpinus) willow (salix) and ash (fraxinus) for your best chance of success.
Most woody shrubs are not any better adapted to flooded conditions than trees. Common casualties of extreme weather conditions include Forsythia, Daphne, Camellias and Yew: who simply panic in waterlogged soil. These can be grown in a pot, or substituted for plants that can more effectively tolerate volatile weather conditions.
We can probably all think of a few ’hard as nails’ shrubs, such as Fatsia japonica and Viburnum tinus, that can tolerate almost anything you throw at them but wouldn’t it be boring if these were our only options for stormproof shrubs. Cercis Canadensis, one of my all time favourite planting choices, is surprisingly storm tolerant – and can cope with long term drought as well as a good few days of standing water. Hibiscus moschetos is another fantastically elegant shrub that is suspiciously hard to kill!
Cornus mas and Berberis thunbergii are two other shrubs commonly reported to be tolerant of flooding: even during the growing season. An ideal storm and flood tolerant plant partner for your cornus would be asplenium, Liriope, Aquilegia or dryopteris filix mas. Convallaria majalis is another woodland perennial that survives both drought and flooding but it is remarkably invasive and can be hard to control in a planting scheme so it is a less ideal choice on a domestic garden scale. Avoid hellebores and tiarella entirely as they so not cope well with waterlogged soil.
My ‘wonder plant’ award must go to the ornamental grasses – specifically Calamagrostis x acutiflora ‘Karl Foerster’. This wonderful grass is a deserved favourite amongst garden designers, and it is easy to see why. This plant seems to cope with almost anything I throw at it. It will happily grow in saturated soil and standing water . It copes effortlessly with drought and is tolerant of extremely acidic soils. It will return to a stiff upright position after having been bent flat to the ground by 80mph winds and it will stand strong through a soggy winter. My other stormproof favourite is Panicum virgatum: especially ‘Northwind’ and ‘Strictum’ which offer similar ‘superhero’ characteristics, but a softer effect.
Bulbs notoriously hate to be left standing in water, especially Eremurus, and are likely to rot away in waterlogged soil. In gardens where flooding is a prevalent threat, you may be better to plant your bulbs into pots in the autumn and treat them as seasonal bedding to get round this issue: planting them out into the border just a few weeks before they are due to flower. In gardens that only suffer from minor waterlogging, try Camassia - which originates from the moist meadows of North American prairies.
Although flooding is a natural event that can’t be prevented, you can be prepared for it. We all know that organic matter is the key to improving soil performance in drought conditions but did you realise that good soil preparation is also key to defending your garden against the ravages of flooding? Organic matter helps bind clay soils into crumbs, so that water infiltrates more quickly after a downpour. Improving the soil structure also makes water more easily available to plant roots, which can grow through gaps between the soil particles.
You can also help to prepare your garden for storms when you are planting and pruning specimens. Plant small and water deeply to encourage deep roots. These will not only anchor the plant and help it cope with strong winds, but will provide a vital connection to the water table deep underground. Choose multi-stem specimens where possible as these will act as a miniature shelterbelt and help to slow down racing winds.
There are other ways to cheat the weather with plants that are less tolerant of rough and volatile conditions. Drought tolerant plants which are not inherently wind tolerant can be pruned to make them tolerant of wind. Sedum, for example, can be cut back by half in early June – to about 4 inches, or pinched to control its height. I have found this very effective in my windy Midlands garden and my sedum stand strong and structural all through the winter where they used to flop and flail.
We are only just beginning to learn how to garden in a changing climate and I am sure we will continue to be surprised at just how quickly plants adapt to new environmental conditions. For the moment, if we just think a little harder about how we can plan our planting choices to stand up to the unpredictable - and experiment to push the boundaries of our existing knowledge.