When Mary Sue approached me about moderating this subject I expressed some doubts. My experiences are based on gardening in the UK, many thousands of miles from where most of you garden. Crocus species are often quite particular about their requirements and even within the boundaries of the UK growers have very different experiences according to local climatic and soil conditions. Having recently become a father for the second time my time for this potentially huge subject may be limited. However I prepared a piece on this very subject for the Alpine Garden Society Bulletin a few months ago and I am reproducing this below. It is rather long for a discussion group. Reading the first and last paragraphs will give you a good summary, the bulk of the text deals with ten individual species in detail. Knowledge of the prevailing conditions in a plants native habitat is often useful when attempting to grow unusual plants. Finding this information and comparing it to your conditions may be the key to deciding whether a particular Crocus species will grow in your garden. Crocus Pages web site has images of most taxa and some basic information about all. http://www.thealpinehouse.fsnet.co.uk/ I have also posted some images of garden worthy crocus at a page on the PBS wiki which Mary Sue kindly prepared for me. I will add to these according to the plants covered in the discussion. http://ibiblio.org/ecolandtech/pcwiki/… CROCUS IN THE GARDEN Asked to write a piece on ten top crocus species for the garden I was initially enthusiastic. As a holder of one of the NCCPG National Collections, I grow a wide range of Crocus species. However, asking an enthusiast to choose just ten from so many (there are 127 species and subspecies currently recognised in the genus Crocus,) is perhaps unfair! Furthermore, the stipulation that the chosen ten should be good garden plants is a complication. Where is the garden? What is the soil type, aspect, local climate? I live in Norfolk UK with relatively dry summers and I garden on a light, sandy soil, as you read these notes you should give consideration to your local conditions. No crocus species are truly native in the British Isles although Crocus vernus and Crocus nudiflorus have been naturalised in a few locations for centuries. The genus Crocus has a distribution centred on Turkey and the Balkans but including Morocco, Iran, Western China and Poland at its edges. So in British gardens at least we may struggle to find them an ideal home. However the two species mentioned above provide an ideal starting point for this short article. Both are clearly well able to adapt to life in a maritime climate having survived for so long here. They also point the way to the division of the chosen ten into two groups, spring flowering and autumn flowering. Crocus nudiflorus is native to Southern France and Northern Spain being especially common in the Pyrenees, its native habitat being moist meadows, and the local climate involving significant summer rain. It is easily cultivated in undisturbed borders in the garden, while it can also be naturalised in grass as in the alpine meadow at the RHS Gardens at Wisley. Increasing by stolons, which spread out from the parent corm, it can also be raised from seed, flowering in three or four years from sowing. The plant is leafless at flowering time, the purple flowers being carried aloft on a strong tube which stands up to the early autumn weather much better than the more widely and cheaply available Crocus speciosus. In my experience, in dry East Anglia, it increases only slowly in the garden but will survive even in relatively overgrown situations. I am gradually establishing more Crocus nudiflorus in the garden by planting out the flowering size corms at each repotting. I grow on the smaller corms and stolons in pots, where they make flowering size in two or three seasons and do so more reliably than in the open garden. Crocus speciosus is certainly the most easily obtained autumn flowering crocus species, available from most garden centres where you can get ten corms for the price of one of the 'rarer' species. Native to Turkey and the Caucasus where it grows in alpine turf, pasture and light woodland, in the garden it can be grown in a variety of positions in most soil types provided that it gets a dryish summer rest period. Although it can also do well in grass, given the vagaries of the British summer, it may be best to plant Crocus speciosus in free draining soil in raised beds. I find that the flowers are very prone to flop; growing it through low growing plants can help provide support. It is also cheap enough to be planted in quantity in patio pots interplanted with winter pansies for some autumn colour by the back door. The named clones offered in commerce are forms selected for flower size, good colour and markings. Some of the nicest have very strongly veined inner petals, a feature quite common in wild forms. Plants raised from seed of 'unselected' Crocus speciosus are usually smaller flowered than the horticultural clones, very attractive but offering no advantage to the gardener over the trade forms. Crocus pulchellus, closely related to Crocus speciosus, is also offered by some garden centres but the message here is 'buyer beware' as some Dutch stocks are mixed hybrids with Crocus speciosus. These two species combine to produce a range of intermediate forms, some of which are very attractive, however few have the delicate charm of true Crocus pulchellus. In the wild the two species have adjacent but distinct distributions, Crocus pulchellus, the more western, being common through NW Turkey and the Balkans. Its native habitat is in moist grassland and thin woodland and it experiences some summer rain. The yellow-throated flowers with white anthers (the two obvious differences with Crocus speciosus,) are usually lilac. They have a distinctive goblet shape and are carried on stronger tubes than Crocus speciosus, which makes it less prone to flop over than its close relative. Like Crocus speciosus it can be grown in a variety of situations in the garden, but is especially suited to raised beds and the rock garden where the beautiful flowers can be closely observed. It increases by producing small cormlets around the parent corm, grown in pots under glass the rate of increase can be rapid. Crocus niveus is less widely grown than the aforementioned species but can be an equally good garden plant. This species has some of the largest flowers in the genus, flowers which are produced with the leaves (the previous three species flower before the leaves appear), and borne on strong tubes. The flowers may be white or lilac, in the latter case they are usually strikingly bicoloured. Surprisingly it failed to impress in RHS trials a decade ago but in my experience this species stands up to bad weather better than most autumn crocus. Native to Southern Greece it grows in olive groves and dry scrub at relatively low altitudes. In the garden it prefers a sunny well drained position and when suited it will increase by corm division and produce seeds. Seed is usually available in the AGS seed exchange and represents the cheapest way to acquire this (and other) species. However, this plant is available from specialist bulb suppliers and its ready increase and showy flowers make it worth some expense. Crocus banaticus is unique in the genus having three outer petals much larger than the inner ones. The flowers are usually lilac or purple with a froth of concolorous style branches at the centre. There are several white forms in cultivation; a particularly large flowered one has recently won awards at AGS shows. Found in the wild almost exclusively in Romania, this is a plant of meadows and deciduous woodland, which enjoys continuous moisture through the year. This makes it the best autumn flowering species to choose if you cannot provide the well-drained site that most of the others need to thrive. Equally if your garden experiences long periods of drought, this is a plant to site with care, as it prefers to be kept moist (though not waterlogged) in summer. It can be associated successfully with dwarf ericaceous shrubs and will also grow happily in grass. Seed may offer the best method of increase, as corms do not usually increase very quickly in the open garden. All the species discussed so far will flower between September and November in the garden depending on the season. There are many others that will do well in the garden given suitable conditions; CC. goulimyi, kotschyanus, longiflorus, laevigatus and tournefortii could be used to make up the chosen ten. The brief here, however is to detail five for autumn and five for spring, which brings me to Crocus vernus the other naturalised alien mentioned earlier. Crocus vernus has a very wide distribution, stretching from the Spanish Pyrenees, through the Alps into the Balkans and north to Poland and Western Ukraine. Typically a mountain plant, it can be seen carpeting alpine and subalpine meadows and woodland soon after the snow melts. Two subspecies are recognised. Subspecies albiflorus is generally associated with the higher parts of the Alps and Pyrenees where the small, generally white flowers may be seen as late as early July in the highest places. (See the images on wiki.) From a gardeners point of view however it is subspecies vernus that is the garden crocus par excellence. This is the plant from which the popular Dutch crocus have been selected. The clones in commerce are generally larger flowered than 'typical' Crocus vernus, but even in unselected forms the flowers are of good size and robust constitution. This is indeed 'everyman's crocus', thriving in all except the hottest and driest places and indifferent to soil type. It is perhaps at its best when grown in grass and is memorably used in many parks and gardens throughout the UK. There are a number of very attractive forms available from specialist nurseries and through the seed distribution. Some of these have in the past been recognised as distinct species. Names such as Crocus scepusiensis and Crocus heuffelianus refer to plants from the east of the natural distribution with flowers having a darker tip to the petals. An Italian plant with purple almost waxy petals has been known by the name Crocus napolitanus. All of these plants are good doers in the garden, very suited to the rock garden where the Dutch crocus can look rather blousy. All forms are easily raised from seed and will increase by corm multiplication over the years. Spring-like weather in the UK can occur in almost any of the winter months and Crocus imperati, which is officially a spring flowering species can flower as early as December. Native to Western Italy it flowers in the wild from January to March, buff coloured buds marked with purple stripes opening to reveal bright lilac purple inside the flower. There are two subspecies separated by small botanical differences. Despite the often inclement winter weather this species makes a good garden plant in well drained soils in a sunny spot. I have seen buds encased in ice after a January snowfall open in perfect shape a week later. In a cool settled spell the plant can be in flower for four or five weeks at a time of year when there is little colour in the garden. Some specialist bulb suppliers offer a form named 'De Jager' which is probably a form of subspecies suaveolens. Subspecies imperati, which may have larger more extravagantly marked flowers, is occasionally offered by the seed distributions. Flowering later in spring and an equally good garden plant, Crocus corsicus is another species offering a dramatic colour change. As it' s name suggests it is native to Corsica, growing in scrub and on rocky hillsides. (See The Alpine Gardener Vol 70, p 130 for a photograph of this species in the wild.) Not usually flowering in the garden until late February or early March, the yellowish outer petals are usually strongly feathered purple but open to reveal vibrant lilac inner surfaces. Once again this is a plant that needs a well-drained soil and a sunny spot to thrive in the garden. I occasionally give lectures to gardening clubs about Crocuses and feedback from gardeners in the cooler, wetter North West of England suggests that this species is less reliable outdoors but remains an excellent subject for winter colour in pots under cold glass. Some specialists still supply Crocus corsicus reasonably cheaply and this clone can increase quite freely given optimum conditions. Seed is occasionally available. I hesitate to mention Crocus tommasinianus for to some enthusiasts it is a roguish weed but for the purposes of this article its merits (just) outweigh its misbehaviours! Here is a species that when suited can colonise large areas quite quickly. Increasing by seed and the production of many small cormlets it has some of the vices of the much-maligned Grape Hyacinth, Muscari armenaicum. However, it redeems itself by brightening the late winter days with commonly lilac flowers sometimes with a buff or silvery reverse to the petals. Found in the wild growing in deciduous woods in S. Yugoslavia, SW. Bulgaria and NW. Hungary, it is fairly uniform but can be abundant when found. There are a number of named forms available in commerce and from specialist bulb suppliers. 'Roseus' has pinkish lilac flowers, the closest thing you will find to a pink crocus. 'Pictus' has darker purple flowers with silvery tips to the petals. 'Bobbo' is lilac with cream coloured outer petals and all the petals have white tips, a striking combination especially when the flowers are half open. There is also a claret coloured form that is more difficult to find but equally garden worthy. All of these unusual forms will set seed but their progeny tend to be a mongrel bunch, rarely matching the parents exactly. Crocus tommasinianus will tolerate more shade than most crocuses, (they are generally a family of sun lovers,) and can associate well with snowdrops in both formal and natural plantings. It also does well in grass. It is probably not a wise choice for the rock garden owing to its' all conquering capacity although I have heard of people who cannot establish it in their gardens owing to its palatability to rodents. Unfortunately all crocuses are potential rodent food, their corms being a neat parcel of starch! Crocus biflorus is a complex of many subspecies mostly found in Turkey, which despite extensive study and research in garden, laboratory and in the wild continues to defy the efforts of man to fit it into a neat classification. It does however offer the gardener many attractive garden plants. In commerce the so-called 'Species Crocus' are often either forms or hybrids of Crocus biflorus. These are usually excellent garden plants given a sunny position although they are not as robust as the large Dutch crocus derived from Crocus vernus, being less tolerant of summer moisture. Apart from those commonly available there are several forms of Crocus biflorus offered by specialists. Crocus biflorus weldenii 'Fairy' has pure white petals, the outer three intensely stippled with lilac flecks. Crocus biflorus alexandrii is also pure white, this time with dark purple outer petals, a very striking combination as the flowers open. The so-called 'Scotch Crocus' is a sterile form of Crocus biflorus subspecies biflorus, which is white with a yellow throat and prominent purple veins on the outer petals. All of these will thrive in a well-drained soil in sun. As with the autumn selection there are species that have been omitted from this chosen ten which will succeed in many gardens, notably CC. sieberi, etruscus, minimus, pestalozzae, malyi and fleischeri, plenty of material for the 'second eleven' article. We are fortunate that so many Crocus species are in cultivation, available from specialist suppliers or as seed from various exchanges. This very availability indicates that these species are not difficult to cultivate given a little extra care. The cultivation of crocuses in the open garden does have a number of drawbacks. The corms are palatable to mice, rats, voles and squirrels in the UK (and a whole range of similar rodents in the USA). Various precautions are possible if you experience these problems but the battle is never likely to be entirely won. Like many growers I often resort to pot cultivation, if only to keep a back-up stock to replace any losses of the less common species. Also the delicacy of the flowers, which makes them so attractive, makes them vulnerable to inclement weather. Autumn flowering species of Mediterranean origin adapt well to areas that have a climate with Mediterranean influences. I find that the autumn flowering species can look bedraggled during a prolonged rainy spell, although this damage to the flowers is only superficial and the plants still grow strongly. Species from high mountains, especially those which flower close to melting snow, are often more challenging in lowland gardens where winter temperature fluctuations induce growth at times when light levels are low, subjecting plants to many unfamiliar stresses. The cultivation of all of these plants in the garden (except perhaps Crocus vernus and Crocus tommasinianus) relies on the choice of a suitable position. As gardeners we often need to give attention to plants' individual requirements to get the best out of our 'investment'. Given this attention to detail it is possible to enjoy a variety of Crocus species flowering in the garden from September until March. Further Reading. Bulbs. Roger Phillips and Martyn Rix. Pan. ISBN 0-330-30253-1 The Smaller Bulbs. Brian Mathew. Batsford. ISBN 0-7134-4922-5 Growing Bulbs. Brian Mathew. Batsford. ISBN 0 7134 4920 9 Bulbs for the Rock Garden. Jack Elliott. ISBN 0 7134 7424 6 Growing Bulbs. Martyn Rix. Timber Press. ISBN 0 7099 2248 5 The Crocus. Brian Mathew. Batsford 1982 ISBN 0 7134 3390 6 (now out of print but obtainable through specialist second hand book dealers.) Journal of the RHS, 'The Garden' Vol 21, Pt 7, pp402-405. Report on the trials of Autumn crocus at Wisley by Brian Mathew and Alan Edwards. The Crocus Pages web site http://www.thealpinehouse.fsnet.co.uk/ has information and images of all the plants mentioned. Tony Goode. Norwich UK. Mintemp -8C (Zone8?)