Easy Composts for Alpines

Transcription

1 Volume: 06 Info Leaflet: Easy Composts for Alpines Easy Composts for Alpines Every nursery and garden center (and many Do-it-Yourself stores too!) stock a range of pre-packaged composts under many brand names, but most enthusiastic growers of alpines continue to make their own mixtures for growing alpines in containers, whether these be pots, sinks, troughs or whatever else they choose. It is easy to make your own composts, and not at all complicated. But why make up your own composts? Most branded composts are designed to be suitable for leafy, fast-growing plants; just the opposite of what alpines need. Many branded composts contain fast-acting fertilizers to feed quick-growing plants, while alpines need a long-term supply of slowly-released nutrients. Most alpines need good drainage, but most branded composts do not drain well enough to meet their needs. AGS 2008 Tel: Crocus tomassinianus A successfully planted sink

2 Easy Composts for Alpines What ingredients do you need to mix your own composts? The list below includes the ingredients most often used in alpine compost recipes, but with only a few of these you can make very satisfactory products. Some alpine experts use many more, and insist that at least one of these is essential for success. However, different people specify different ones, so this is clearly not so. John Innes Potting Compost. This makes a convenient and readilyavailable base. Growers usually choose No.2 or No. 3. Note that the name implies that the compost was made to the John Innes recipe. The various manufacturers may, however, depart from this or use raw materials of variable quality. Its chief advantage is that it is sterilized, so is free from weed seeds. Alternatively you may skim the top few inches of soil from a part of the vegetable garden or border, if your soil has a reasonable organic content, but this may introduce pests or diseases. This is not to be recommended if your soil is heavy clay or very sandy. Grit This opens up the compost and improves drainage. The ideal particle size is from about 5 mm down. In the North it may be granite, in the Midlands crushed quartzite and in the South Cornish Grit. All are suitable. Unless you know that the range of plants you grow are limeloving, it is best to avoid limestone and Dolomite.

3 Sand. Suitable materials are widely available under the names Concreting Sand and Grit Sand from Do-it-Yourself stores and builders merchants. Rub some between your thumb and fingers. The particles should be sharp and angular (nor smooth and rounded) and vary in size. It improves drainage. Moss peat. Although some organisations, including the AGS, would wish to see its use reduced, peat is still widely-used in the horticultural trade. It is organic, comparatively uniform, breaks down slowly, lets air into the compost and helps to hold water and nutrients. It is not a source of plant foods. Rub through a garden sieve to remove lumps. Avoid sedge peat, which is far too decomposed and fine. Leafmould. If you can get it or make it, the ideal alternative to peat. Oak or Beech are best. Gather the leaves when they are slightly moist, place in a black polythene bag, poke a few holes in it, fasten the top and store in an out-of-sight place. In 1 2 years the leaves will break down readily when rubbed through a garden sieve (about 7 mm or ¼ inch). Most other leaves gathered from the garden will do, but avoid leathery, slow-decomposing ones like Sycamore and Horse Chestnut and evergreens. It lightens the compost, lets in air, and decomposes slowly to release plant foods

4 Mixing your compost. Composted bark. Another alternative to peat, and a renewable resource! A fine grade, with fragments from about 8 mm down works well. Again it lightens composts, lets in air, holds on to water and nutrients; what more could you want?. It may be difficult to find, but is well-worth seeking out, as the results are so good!. The basic recipes listed below give the proportions of each component to use, measured by volume. Depending upon the quantity needed, you can use an empty pot or a special scoop. Many chainstores offer calibrated plastic scoops if they have a cookery section. After a little while, you will begin to know instinctively what a good mix looks and feels like, and may well leave your measure to gather dust. When asked about their own recipes, experienced growers often say I just throw the ingredients together and mix until it looks right. Until you gain this level of confidence, there is a simple test that you can perform to check whether you have got the mixture right for your alpines: The Expert s Test. Check that your final compost mixture is slightly damp. If not, add a sprinkle of water and mix again. Take a handful of compost and squeeze it in your fist as hard as possible. Open your hand. If the compost falls apart, you have got it just right. If it stays in a lump, there is insufficient drainage; add a little more grit or sand (or both), remix and retest. Simple! Extras. To give long-term feeding of alpines in pots and troughs, add 1% by volume of bone meal to your compost. You will need to water sinks and troughs less frequently if you also add to your compost for these, proprietary water-storage granules at the recommended rate.

5 Suggested compost mixtures. For seeds: 3 parts John Innes Compost No. 1 For cuttings 1 part peat or composted bark For alpines in pots 3 parts John Innes Compost No. 2 or 3 2 parts leaf mould or composted bark 1 part grit Cyclamen coum For alpines in sinks, troughs and raised beds 2 parts John Innes Compost No. 2 or 3 2 parts composted bark or leafmould or peat 1 part grit Polygala calcarea with a Dianthus cultivar

6 For ericaceous plants A commercial ericaceous compost will do, but some dwarf rhododendrons will benefit from the addition of extra sand, up to 20% of the volume. Saxifraga aizoon Allium karataviense Sempervivum arachnoideum Volume 1 Volume: 05 Info Leaflet: Easy Bulbs to buy in Growth Easy bulbs to buy in growth Crocus medius Impress your friends with this autumn-flowering crocus. Lilac-purple flowers with contrasting orange-red stigma. This one does well in moist soils, and will increase by underground stolons. Buy and plant as early Easy autumn bulbs as possible. (5, October) Crocus sieberi Several subspecies and varieties are available, all good. C. sieberi tricolor is a stunner: each flower is bright purple with a yellow base, with a white band between them. Firefly : inner petals violet, outer nearly white. Bowles White : white with a yellow base. Best in full sun with good drainage. (7, February) Although the majority of bulbs are sold in the dry state in late summer and autumn, there are a number which are better bought as growing plants in pots, in winter or Fritillaria meleagris spring. This group includes plants with bulbs, corms, tubers and other swollen parts. Wiry stems hold one or two large nodding bells in shades of purple or white, with a chequered pattern. Will tolerate dry soils once established and self-seed. Buy bulbs and plant them as early as possible; old, dry bulbs may fail to establish. (15 30, April) The hoop-petticoat daffodil. Buy and plant as early as possible in humus-rich moist soil. Conical flowers in many shades of yellow and various shapes, and shiny narrow leaves. All are delightful! (10 15, February April) Narcissus bulbocodium. Narcissus juncifolius Ornithogalum nutans A strongly-scented jonquil species, with small deep yellow flowers on tall, wiry stems. Has done surprisingly well in poor, sandy soils. May also be found under the names N. assoanus or N. requienii. (10 25, March) But why is it better to buy A relative of the Star of Bethlehem with spikes of silvery-white outward-facing flowers. The petals have a some bulbs in growth? green or greyish stripe on the reverse. (15 20, May) Scilla sibirica Brilliant blue, slightly nodding flowers and glossy, dark green leaves. Will take some shade, but not too much. (10, March). Some have no protective skins, so dry out very quickly in storage and may give poor results e.g. Volume Dogs Tooth Violets (erythroniums), fritillarias, lilies. Some do not re-establish well Collect all the Info leaflets and have a complete library of everything to do with growing, caring for and showing alpines. If you need more information please call us or see our website. Many rare and choice plants are only available as seed. ew average specialist nurseries will stock as many as 1 different plants; many will stock far fewer. y contrast, the A S Seed Distribution typically offers in excess of, different kinds each year. A number of companies offer wild-collected seed. hese are a good source of new plants, which may not be in cultivation at all see list at end of this lea et. he A S Seed Distribution also lists seed collected from the wild by members, and occasionally the A S organises seed collecting expeditions. when stored dry for sale. e.g. snowdrops (Galanthus), snowflakes (Leucojum and Acis), windflowers (Anemone blanda), Winter Aconites (Eranthis), Cyclamen-flowered Daffodil (Narcissus cyclamineus), Wood Anemone (Anemone nemerosa), Cyclamen. Some normally have perennial roots, so should not be dried off at all - e.g. trilliums, lilies, cyclamen. Some begin to produce roots in midsummer, so are growing underground before the normal bulb-selling season e.g. some hoop-petticoat daffodils (forms of Narcissus bulbocodium and Narcissus effect! (20, June July) Large pale pink flowers with a bold yellow centre. Will flourish in the hottest, sunniest situations. (20, April) Tulipa tarda Tulipa saxatilis A complete contrast. Glossy yellow petals, each with a white edge and reverse. Must have full sun. (10, April) romieuxii), Star of Bethlehem relatives (Ornithogalum), choicer grape hyacinth relatives (Muscari) and trilliums. Some vary so much in leaf patterns and/or shapes that it is advisable to see what you are buying, and choose the ones you like best e.g. cyclamen, trilliums, erythroniums. Some have a wide range of flower colours and sizes, so again it is best to see the plants in growth e.g. cyclamen, trilliums, Erythronium denscanis. Some cyclamen have scented or unscented flowers. to give increasing value. Many bulbs are short in stature, so associate well with alpine plants in general. Planting a good range of dwarf hardy bulbs can add colour to the garden throughout the year. attention, and will not outgrow its space; this is real labour-saving gardening! A natural hybrid found only once in Scotland. this plant needs a warm position with good It forms a true miniature drainage. It has silver-grey leaves and bright yellow tree: in effect a bonsai daisy flowers in late spring. Ultimate height and without any special spread about 25 cm. growing or training. It forms a proper smooth, gnarled trunk, and the leaves are greyish. Even This dwarf form originated in America. Primrose small specimens give an impression of great age. yellow flowers appear on Catkins are sometimes produced in May; they are the bare stems in spring. silky and light yellow. Very slow-growing. Reaches to 30 cm. Pinch out the tips of vigorous shoots to encourage a A dwarf mountain ash. bushy habit. White flowers in spring and crimson berries in autumn. Lovely From the Balearic Islands. Highly recommended autumn leaf colour for a sunny, well-drained position, though possibly too. To about 40 cm. not suitable for the coldest gardens. It forms (There is a suckering upright branches to about 35 cm clothed with form which may strange, wavy-edged leaves with a warty surface. become an invasive The glossy yellow flowers with very prominent pest; beware.) anthers are freely produced in summer or autumn. Bulbs are the classic plant which survive and flourish, in areas which suffer summer drought. Most bulbs will increase steadily over the years Some shrubs flower outside the main spring and autumn seasons of alpines and dwarf bulbs. A carefully chosen dwarf shrub can be left in place for as long as twenty or thirty years, needs minimal Many bulbs are very easy to grow and cheap to buy, so represent excellent value for the garden, or for pots and containers. Some can be planted in August September and be in flower the same year; almost instant results. Others flower in the following winter and spring and can give early colour in the garden. Deciduous shrubs do the same, but may also offer attractive autumn colour, extending the season of interest. Sorbus reducta (non-suckering form) Hypericum balearicum Evergreen shrubs provide a permanent framework of colour in the garden, when lower-growing alpines are not in flower. Why grow dwarf shrubs? Forsythia viridissima Bronxensis So why begin to grow bulbs? The bulb trade has been flourishing for centuries, and the range of bulbs on sale is so large that the beginner can be totally overwhelmed by the choice available, some at very high prices. Add to this the range of nurserymen attending AGS shows who specialise in dwarf bulbs and it is difficult to know where to begin. Nurseries and garden centres offer many shrubs under the label small. Many are slow-growing rather than truly small, and in time can outgrow their space and overwhelm alpines and small bulbs in the garden. There is, however, a range of truly dwarf shrubs, ideally suited to the small alpine garden or a trough on a patio. The finest recent introduction for the garden. Forms a neat dome to about 60 cm with pale pink flowers. After the main flush spring, flowers intermittently through the year. Widely available from garden centres and nurseries From the Drakensburg Mountains in South Africa, Salix x boydii Euryops acraeus No garden should be without it! The classic dwarf conifer, growing into a close candle-flame shape. The greyish-green foliage is tight and neat. May reach 1 metre tall after 30 years growth. Juniperus communis Compressa Easy Dwarf Shrubs Daphne x transatlantica Eternal Fragrance Volume: 03 Easy autumn bulbs cm, but slow-growing and never out-competes its neighbours A British native. The strongly scented pink flowers are borne on the bare twigs in winter, followed by red berries. You may see Rubra with very deep, almost red flowers, and Alba or Bowles White, both white-flowered forms with yellow berries. Occasionally may reach 90 Info Leaflet: Easy autumn bulbs From north-west India, this forms a congested, twiggy shrub with thee-lobed dark green leaves. Fragrant, bright yellow flowers are freely produced in June, often followed by black berries. Well-drained soil in full sun. Up to 35 cm after ten years. A very vigorous form (or impostor) is sometimes sold under this name, so check on the growth rate with the supplier! Volume: 04 Info Leaflet: Easy Dwarf Shrubs Jasminum parkeri Daphne mezereum Easy Dwarf Shrubs Sternbergia lutea Wonderful glossy upward-facing golden goblets, followed later by glossy, dark green narrow leaves. For the hottest, sunniest place in your garden. (10, October) Tritelia laxa Queen Fabiola Generous heads of bright blue flowers. Plant in clumps 10 cm apart for a stunning Version 1