In like a lion?
March can be an odd month. It’s officially spring (the Vernal Equinox falls on the 20th), though doesn’t always feel like it: the Radcliffe Observatory in Oxford has been recording temperatures since 1815, and, on the night of March 13th 1845 it registered -12 celsius (10 degrees Fahrenheit). I imagine that in a village like Eynsham it was several degrees colder. By contrast, March 29th 1965 saw 22.1 degrees (almost 72 Fahrenheit), a really warm spring day.
Therefore we gardeners should perhaps be cautious about engaging in some typical spring tasks. I am not an “autumn tidier”, preferring to leave it till spring to remove the remains of last year’s flowering stems and the like (some of these can provide refuge for overwintering insects, and the odd pile of leaves in a corner might shelter a hibernating hedgehog or toad), but I’ll be finishing all such work off in the next few days.
In our part of England, mid-March is a good time to prune roses. Most of mine are old shrub types, so require little pruning except the removal of dead stems and any others that cross over and rub against one another (such damage can encourage disease), but the hybrid teas and floribundas will get stronger treatment, and I have two climbers which require serious attention, especially “Gertrude Jekyll”, a wonderfully blousy pink lady that flowers all summer, but with a vigour that requires dealing with on an annual basis. Such a strong grower should have every side shoot that flowered last year reduced to two or three buds from its main stem. I have wire supports on the fence against which this rose is growing, and wherever I can I tie the remaining shoots as horizontally as possible onto these, thus ensuring lots of flowers all along their length rather than a clutter at the top.
Many shrubs, such as spiraea and buddleia, that flower after midsummer, can also be pruned in March. If they are well established and maybe a bit crowded in their centres, cut a few stems right to the ground, and cut back the stems that flowered last year to within one or two buds of the older woody framework. This gives a much better result than the frequently encountered “haircut”, with all stems the same length and often a lot of old and even dead material in the centre.
Plants grown for the striking effect of their stems in winter, such as dogwoods (like Cornus “Midwinter Fire”) require much more drastic treatment, and now is probably the last time to deal with them. Cut all the stems back to within six inches (15 cm) of the central stem(s) – this is almost like the stooling of plane trees so familiar on London’s streets. It looks dreadful for a while, but the shrub will soon start to put out new shoots ready for next year’s display. On the other hand, more tender shrubs such as lavender, salvias, hydrangeas and fuchsias should be left alone till April: their old growth will protect the new from any late frost that may be visited on us. This does not apply to Hydrangea paniculata and arborescens cultivars, which can be reduced now to about 10 inches (25 cm) in height (or 2 feet/60cm if a taller shrub is preferred). Such regular pruning is not essential, but ensures better flowering. Other species, such as Hydrangea quercifolia, require no regular pruning.
All this differing information about pruning may seem confusing, but it is definitely worth taking the trouble. The Royal Horticultural Society web-site provides valuable instruction on how to prune virtually any shrub, climber or tree you may wish to grow.
If you are a keen vegetable and/or fruit grower, I would also encourage you to head to this “what to do” page: https://www.rhs.org.uk/advice/grow-your-own/in-month/march
In a few words, it really is “full steam ahead”!