Planting and Global Warming

The easiest way of getting yourself a spot in the on the gardening pages of the weekend Broadsheets is to send them a piece on gardening and global warming. Grey leaved, Mediterranean plants are a ‘must’, and we will all be growing pineapples and ginger on our allotments in a couple of years.

But the truth and practicalities are, in fact, very different from what the uninformed gardening media will tell you.

Take Mediterranean-type plants, for instance.

Yes, these will thrive with minimum feeding and watering in a hot, dry summer. But what happens during a normal British winter?

The rain comes down, the roots get soggy, the hairs on the leaves become waterlogged, and the plants seldom survive their first winter.

We are told to mulch with anything we can get our hands on, but I know from experience that if you mulch Mediterranean-type plants, the soil retains too much water and they rot.

By all means, grow this kind of plant in a restricted environment, like a raised bed or tub, where you have control over the weather (watering sparingly when necessary in summer, moving under cold glass in winter – if you can afford it). But it will be a long time before we need to forget about all the garden plants we know and love.

This year (2009) has been a typical example. In Lincolnshire, we had a dry, warm spring and early summer, followed by a wet July and first half of August. We then had weeks and weeks of dry weather, broken only by one downpour, until the second half of October, when the heavens opened and now the soil moisture is back to normal. But this is a different pattern from last year, and the year before, and the year before that, so we cannot as yet make any generalisations as to what we should expect in years to come.

Admittedly, autumn is late. As I write this (1st November), the colour in the garden is magnificent. I still have magnificent hanging baskets of begonias and impatiens which blend so well with the autumn colour on the trees and shrubs. The roses are still in flower, and the hostas are only slowly turning yellow. I am champing at the bit to get on with my spring bedding and annual tidy up, but the herbaceous plants and shrubs are much too good to start cutting back and I have decided to lie back and enjoy the display while it lasts.

Therefore, I don’t dispute that the weather is different from what it was when I was a child. We seldom get the penetratingly low temperatures of January 1963, and, if we do, they don’t last for weeks. We don’t get the snows of early 1979, which were still hanging around in some parts in early May. But we still get sufficient of the kind of weather that our popular garden plants enjoy. It is too early to discard them in favour of cacti and bromeliads.

So, rather than ripping out traditional borders and abandoning our favourite trees and shrubs, what easy steps can we take to adapt to the weather shift we are experiencing at present?

It is very sad that the maples of Westonbirt Arboretum are showing signs of stress – they are in my own arboretum - but maybe we should be thinking less in future about growing plants in alien environments, and concentrating on species that can cope with the wide range of weather conditions they are likely to experience in this climate.

The deciduous spindle, Euonymus elatus, is one such shrub. Its autumn colour rivals any Japanese maple, thrives (so far) in our conditions, and has pretty and fascinating fruits as well.

I certainly will not replant any Japanese maples- or anything similar that is showing signs of being unhappy - that I unwisely planted in a rash moment.

Back to top