Saturday, 14 March 2015

Leave your snowdrops alone!

If I told you that parsley belongs to the devil and can only be sown on Good Friday you'd tell me that's ridiculous. If the devil himself walked this earth he probably wouldn't be much interested in your parsley patch! This is just one of many pieces of myth and folklore that exists in gardening.

Planting snowdrops 'in the green' (in spring, while in growth) is a very well known piece of gardening advice which, even now, is still proffered by some fairly big names in the world of gardening. It's also wrong. This age-old advice about how to buy and divide snowdrops is seen every year; 'you must divide your snowdrops once they finish flowering' the magazines and gardening experts will tell you, but they're propagating a myth!

No plant likes to be disturbed when it's in full growth, and you'll know already that if you want to buy spring flowering bulbs then you buy them in autumn, and you buy autumn flowering bulbs when they're dormant in spring. Lifting and dividing bulbs when they're in growth causes damage to roots, damage that is not repaired, and causes them to go into dormancy early. If you lift and divide your snowdrops after they've flowered then your bulbs can easily go into dormancy a full month before they really should, and that month is when the bulbs are building themselves up ready for next year. Wait until the bulbs are dormant and you won't cause any damage, and your snowdrops won't even know they've been disturbed!
Leave them alone!
So where has this myth come from? The most likely answer by a long way is the nursery trade. Snowdrops don't like being handled and processed like other bulbs; they have a thin tunic and are quite delicate, so don't tolerate the process of being lifted, dried (artificially or out in the open), cleaned and then stored dry in boxes for weeks or months on end like other bulbs. Dry snowdrop bulbs are a notorious failure when bought in bags from garden centres, and this processing is why! Nonetheless there's good money to be had from selling snowdrops in flower, so it became standard practice to lift clumps of snowdrops in growth, divide them and sell them 'in the green', bypassing the problems of the bulbs drying out. However as I've already said, dividing bulbs in growth causes damage and weakens them, so by removing one danger to a crop of snowdrops the growers have introduced another!
G. 'Grumpy', especially grumpy if you move it now!   

This practice has translated into advice for gardeners; every year the same 'divide your snowdrops after they've flowered' advice comes out, but gardeners don't have commercial pressures to worry about so really shouldn't and mustn't follow this advice. The best practice for dividing your snowdrops at home is as follows:
  1. As the clump(s) you want to divide start to yellow and die back naturally in spring, mark the clump(s) with a cane or another marker.
  2. In July or August go back to your clumps and dig them up with a generous amount of soil.
  3. Gently tease the bulbs apart with your fingers. Remember that these bulbs are in danger of drying out, so if it's a warm/dry day then take the bulbs somewhere cool while you tease them apart, so work in the evening so it's nice and cool. Also be careful if you grow several types of snowdrop and don't want to mix them up!
  4. Replant the bulbs as soon as possible. If you want to share them with someone else or can't plant them straight away for some reason then keep them nice and cool, packed in peat (if you still use it) or peat free compost (bearing in mind that while damp peat stays cool and moist for quite some time, many alternatives don't, so be extra vigilant to make sure they don't dry out!). Snowdrops can be attacked by rodents, so be sure to protect them appropriately.
  5. Once the bulbs have been planted out at the appropriate depth then give them a decent watering in. Mark the position of any new clumps if required.

Over the autumn and winter the snowdrops will begin their natural cycle, growing roots and shoots ready for a great spring display!

Snowdrops sold in pots are often, certainly from specialist nurseries, potted the previous summer and grown in mouse-proof cold frames. In an ideal world you should keep them in their pots and mouse free, and then plant the bulb(s) from the pot into the garden in July or August. Sometimes keeping them in a pot is tempting fate and they might fare better in the garden, but here there is a conundrum; do you risk disturbing the bulbs by planting them individually and risk breaking the roots, or do you gamble and leave them in the compost they were growing in, a compost that might keep too much moisture around the bulb when it's in your soil?

If you've already bought some snowdrops 'in the green', or are given some, then it's a case of minimising their trauma; plant the clump as it is straight away, without dividing it up, and water it in well. If you want to divide the clump then make sure you mark its location as the snowdrop die back and follow the instructions above. If you can bear to leave the clump as it is then your bulbs will do much better if you wait until the second summer after planting (probably 18 months) so the snowdrops can recover from being moved.

There will almost certainly be people out there reading this saying to themselves “I've always moved/divided my snowdrops 'in the green' and never had any problems”. You have had problems, but what you've put down to poor performance while your snowdrops are getting established is actually a result of damage to the bulbs by improper handling. Divide and replant in July and August and you will almost certainly see a big difference in performance. Go on and try this method, what have you got to lose?!