Where to plant your snowdrops.
Shade or Full Sun?
Whether you decide to plant in shade, or in more open ground in full sun, depends on the variety of snowdrop you are planting. Most snowdrops will enjoy dappled shade, but a good proportion will be happy in full sun – alpinus and platyphyllus naturally occur above the tree line where there is no shade from trees and some species such as peshmenii actually grow in the wild on open exposed cliff faces. None, I have found so far, grow happily in deep shade. Some will happily grow in different areas from partial shade to full sun… in the garden here at Bruckhills Croft our original patch of nivalis, the Common Snowdrop, which was here before us when the house was derelict, sits at the base of a south facing wall in full sun and flowers prolifically each year, but another is at the base of a mature common ash tree and gets considerable more shade.
My advice is to do a bit of research first, but if the variety you have acquired is one of the common species or a hybrid then they will generally do best in temporary partial shade, but if it is one of the species named above then give them an open planting position.
Another factor to take into consideration is the hardiness of the variety of snowdrop… some of the less hardy species such as ikariae do better if they have less shade.
Damp or dry?
Most snowdrops enjoy good drainage, platyphyllus is the exception which enjoys damp soil, coming as it does from alpine meadows where the ground is covered with water from late melting snow. Some will tolerate dry soil in summer – our original nivalis at the base of the south facing wall gets baked in summer and peshmenii naturally occurring in rock crevices must dry out completely between limited showers.
The most universally enjoyed ground will contain a certain amount of humus from decaying plant material, mostly leaves from herbaceous plant and deciduous trees and shrubs, interspersed with large particles of mineral matter from sand and grit. The humus retains the moisture, whilst the mineral content allows excess to drain away. Fine mineral content in the form of silt and clay should be avoided as this doesn’t allow water to drain away and causes constantly wet soil which encourages rot.
In the soil or in containers?
Most of our snowdrop collection is in the soil, temperature and moisture remains more consistent, but snowdrops will grown quite well in containers. Some we grow in alpine troughs as some varieties really enjoy the extra drainage, some we grow in an alpine greenhouse as they need some protection (not all species are hardy enough for NE Scotland, and all are backup plants are grown in raised beds where we can keep them protected from pests incase we lose any in the main collection.
Containers work well if you struggle growing snowdrops in your soil because you can tailor the potting mix to suit – such as our alpine toughs. if you have really heavy clay or extremely well draining sand then containers may work well for you. Ensure the containers are as large as possible as this will protect the bulbs from temperature and moisture fluctuations, and from freezing solid in really cold weather.
Galanthus ‘Midge’ – one of our smaller snowdrops, which would be lost in a border, does well in an alpine trough
The ideal habitat for the vast majority of snowdrops is the edge of deciduous woodland. Open to full sun in winter when the sun is at its weakest, but shaded from harsh summer sun. Not everyone has room for a deciduous wood, but you can replicated it with a little ingenuity.
There are lots of small deciduous trees that are suitable for a small garden, there are smaller cultivars of Rowans, Silver and White Birches and even apple trees which will provide some shade in summer. Avoid conifers as they cut out too much light and the ground is often starved and dry all year round.
There is an even wider range of shrubs available than trees. Deciduous shrubs are best, their leaves also improve the soil structure as they decompose each winter. Dogwoods work particularly well as the coloured stems are a great backdrop to clusters of snowdrops in winter. Evergreen shrubs also work well, including conifers as long as the lower branches are removed to allow light and rain to the snowdrops underneath.
These are often overlooked, but the timing of their season of interest is opposite to the snowdrops and any flowers and foliage will have died back leaving the stage open for the snowdrop flowers. We use hardy geraniums a lot… the foliage allows rain down to the soil all year round, but provides shade throughout the summer while the snowdrop bulbs are dormant stopping them from being baked by the sun. Other suitable herbaceous plants would be hostas, asters, delphiniums and astrantias. Plants that work less well are crocosmia and ornamental grasses as they tend to invade the clumps of snowdrop bulbs and crowd them out.
Alchemilla mollis – Lady’s Mantle – a useful shade giving herbaceous plant for snowdrop cover
There is some discussion and disagreement around whether snowdrops need feeding or not, and if it is detrimental – some people believe feeding causes too much lush foliage to the detriment of flower production.
We do feed, but we think we are quite light handed with it. Most of our snowdrops grow in the ground amongst herbaceous plants and shrubs so you a certain extent will benefit from the annual mulch of decomposing leaves, and from any mulching with home made compost done to the borders in general.
In addition to this we do an annual dressing of bonemeal which is sprinkled around the clumps of snowdrops as the season begins. Bonemeal is a slow release fertiliser which takes around 6 weeks before it begins to be broken down by soil bacteria and made available for plants, so by using it at the beginning of the season, there is plenty of time for the snowdrops to access this resource from when they start to emerge, then flower and through the time they die back, feeding the bulbs ready for nest year. we see it as less of a feed for the current season of flowers.
If perhaps your soil is particularly impoverished then maybe you could consider a foliar feed such as diluted tomato feed or seaweed to help flowering in the current season as it acts quickly.
One of several varieties of swift moth which are a pest of snowdrops
Slugs and snails
Slugs and snails can be a big threat to snowdrops in some gardens, and in others they seem to leave them alone even though they are present. We lose the odd flower, or the tip of some young foliage will be grazed off, whilst all around snowdrops are not touched. there doesn’t seem to be a favoured variety, and with damage being sporadic it is hard to tackle. I find barriers are ineffective, and other snowdrop growers seem to be the same. Because they do so little damage, I just leave them alone. If they are a big problem in your garden, the best method to tackle them is probably nematodes.
Snowdrops have relatively few insect pests, probably due to the presence of galanthamine which deters most sap sucking pests. Narcissus Fly and Swift Moths however love to lay their eggs on snowdrops and their larvae will eat the bulb until it disappears completely. There used to be systemic insecticides which worked well, but these are no longer available. The best way to keep snowdrop safe from them is barriers such as fleece, which is ok for small areas, but not really useful for plants out in the border or in mass drifts. The fly and the moth find the plants by scent, so to reduce the risk of attracting the pest avoid disturbing or damaging the foliage of the snowdrops in the growing season – we don’t lift and split snowdrops ‘in the green’ for this reason. Its the same as you try to avoid weeding and thinning carrots when Carrot Fly is present.
Eelworm can be a serious pest of snowdrops, causing distorted foliage and deformed bulbs. The best way to avoid this pest is to buy your plants from a reputable nursery to avoid importing the pest in the first place. This pest can be brought in on many varieties of bulb, so make sure you apply the same levels of biosecurity to all plant purchases. If you suspect you have eelworm infestations in your garden, do not grow snowdrops in that area.
Raised bed with an Enviromesh cover as pest control – removed in late autumn once the threat of flying pests is over
Grey mould – Botrytis is a common fungal infection affecting all plants if the conditions are right for it. It is more common in enclosed environments such as cold-frames and alpine houses where airflow is reduced. Keeping doors and windows open to allow good airflow reduces the risk. If you do spot it amongst your plants, remove and isolate the affected plant, remove any foliage and treat with a fungicide and improve ventilation. Probably also a good idea to remove the surrounding planting media and replace with fresh.
Fire – Schlerotinia gladioli causes foliage to become stunted, turns yellow and dies off prematurely. Remove the affected plants as above.
Leaf scorch – Stagonospora curtisii, is more familiar to daffodil growers but can affect galanthus too. The foliage gets grey oval marks, the tips go brown and the following year the plant fails to emerge, the bulb underneath will have rotted away leaving just a brown husk or nothing at all. Treat as above.
If the plants affected are particularly expensive it may well be best to lift, soak in fungicide and try re-sprouting in sterile vermiculite. Make sure the fungicide specifies that it treats the fungal infection you suspect you have, not all fungicides treat all infections.
Lifting and splitting
Like many herbaceous plants and bulbs, lots of varieties of snowdrop really benefit from being lifted every few years and divided. Clumps of bulbs can become extremely congested, and if left overcrowding each other, will stop flowering well – in fact they may stop flowering altogether and in the worse case can rot. It can be as drastic as one year you have an apparently healthy clump of snowdrops, and the following year it has rotted away completely or may leave evidence of what has happened in a ball of smelly squishy bulbs. This is more important to look out for if you grow your bulbs in containers or n baskets plunged into the border as they have a fixed barrier which does not allow for expansion of the clump.
As mentioned before, we believe lifting ‘in the green’ can attract pests who work on scent (a bit like carrot fly) so we lift all our bulbs that we think need splitting in July when the plants are completely dormant and there is no foliage. This involves good lists with good planting plans and clear labelling so we can find what we want when we want it. We also plant into pond baskets plunged into the borders which makes lifting relatively easy with no damage to the bulbs from forks or spades.
Bulbs are tipped out of their baskets and carefully pulled apart before checked for any sign of damage or pests, then about 1/4 will be planted back where they came from with some fresh compost mix to refresh the planting hole. This gives enough space for future growth.
A lovely clump of Galanthus Hippolyta – one of the first snowdrops we added to our collection