March in the garden

If you are reading this article then I am assuming it is because you have an interest in gardening and not because you are seeking amusement by critiquing my somewhat ungainly prose!

Years and years ago, I first veered away from hands-on horticulture by becoming a ‘researcher / writer’ for the gardening magazine Gardening Which?, part of ‘The Consumers’ Association’. Everything I wrote went through a process of rewriting, in house style, so I guess I never learnt ‘elegant’ writing because that simply wasn’t required. I now know, much too late to do anything about it, that this ‘truth is God’ approach suits my, mildly, Asperger’s brain.

Having said that, gardening as a pastime is largely an aesthetic exercise so, although an understanding of Science aids success, I am not entirely immune to the beauty of ‘taming nature’. To this end, March is perhaps the first month of the year, the logical start to the growing season, when the drabness of winter really feels like it is being extinguished by the joys of spring.

The spring flowering bulbs, especially the new ones that were planted last autumn, will be adding a burst of colour and, in the guise of hyacinths and many narcissi, a powerful perfumed haze. Early blooming trees and shrubs, magnolias are the star performers here, are especially welcome for bearing their flowers at a time when the garden is still largely leafless.

The imminent emergence of new growth makes this time of year the last chance to complete the traditional winter tasks. These include planting bare-rooted hedging, rose pruning, mulching of beds and borders, winter digging, wholesale clearance work and anything which might disturb bird nesting sites.

I find that dividing congested clumps of herbaceous perennials can continue into April, at least, because they recover best when the soil temperatures are decidedly on the up. March can still be very cold; remember the heavy snow we had here a couple of years ago.

With sap rising it is important to complete major shrub pruning / tree shaping operations; with buds bursting it may already be too late for some species. If major wounds are created, once winter dormancy has broken, then there is a risk that the cut surface will ‘bleed’ with sap, forced up under pressure, from the awakening root system, weakening the plant. At the very least bleeding is unsightly and something that is best avoided when possible. Open wound sites can also allow fungal diseases to attack the plant and damage it further.

Shrubs grown for their winter stems, Cornus (dogwoods) and Salix (willows) predominate here, should be cut right down to the gound, ‘stooled’. This promotes a fresh burst of new, young, shoots which will provide the strongest stem colour for the desired winter display. This drastic cut back must only be attempted once the plant is well established, not on newly planted specimens, as it relies on the plant having developed a decent root system to support the new growth. A handful of general purpose fertiliser (regular readers will know that I tend to rely on ‘fish, blood and bone’!), forked in around the stooled plants, is beneficial to regrowth.

Cutting to the ground will result in an almost herbaceous type effect, albeit on a more robust scale and without the flowers, but, more especially in the case of willows, these are trees, i.e. they are woody by nature, so another option is to treat them as ‘lollipops’.

This means that they are allowed to grow up, with a single trunk, for a few years just like a ‘normal’ tree. Once the trunk is a few feet above the height required for the ‘head’ of the lollipop, it can be lopped off, lower than the height gained, and kept to this height annually; correctly known as pollarding. Over the years the trunk continues to thicken, becoming more substantial, while the ‘knob’ at the top, where it is pollarded to annually, becomes more pronounced and club-like—you’ll know what I mean if you’ve ever seen one.

These pollarded specimens, of bright winter stems, look really effective when grown as an avenue or in a formal line. Salix alba var. vitellina ‘Britzensis’, the Scarlet Willow, is often treated this way but any similar willow, with attractive bark colour, could be used. A trunk height of no more than your own head height, or head height plus step ladder, is sensible to allow for easy maintenance.

As an antidote to chopping back; seed sowing is a great activity to attend to whenever the weather prevents comfortable gardening outdoors. I’ve always had a soft-spot for alstroemerias and a quick dip into Christopher Lloyd’s Garden Flowers (an indispensable reference book that is now two decades old) reveals that “It is best to sow several seeds to a pot in March, and to germinate them in a cold frame where the temperatures will range from warm in the day to freezing at night. Germination will then be assured… If seed is given uniformly high temperatures, it will not germinate”. Sage advice, as ever, from the consummate gardener and writer.

It’s too early to plant out tender plants, severe overnight temperature drops are damaging with or without a ‘proper’ frost, so keep these gently ticking over in their winter quarters. The longer days, especially when accompanied by a bit of sunshine, will raise the heat in greenhouses / frames so it’s a good idea to start potting up tuberous plants, dahlias spring to mind, which were lifted from the garden in the autumn. They’ll need to be kept frost-free, obviously, but starting them off now will give them a headstart before planting out into their summer flowering positions.

As ever, prevailing conditions will be your greatest steer when it comes to getting on with things in the garden. As I write, we’ve had a very mild and extremely wet winter—I can hardly remember a wetter February. This means that your lawn may well be longer than usual for this time of year. If at all possible it should be mown, on a high setting, but only if this can be achieved without turning creating a quagmire. I always seem to miss the one opportunity when a break in the downpours makes this possible and, in its current saturated state, I cannot see that I’ll be able to manage a decent cut any time soon. I’m praying for a much drier, less depressing, launch into spring.