French garden diary - November 2018
How to be ‘water-wise’ in winter? Do your bit by helping to save water in the garden, writes Cathy Thompson
I have real objections to watering plants continually on many counts: the water table is already low in this part of France; it costs too much money; and I feel a huge amount of guilt watering a ‘mere’ garden when there are children on the planet who don’t have enough fresh, clean water to drink.
There are three classic ways to avoid excessive watering: only grow plants that tolerate dry conditions, mulch your soil to conserve the moisture already in it and water only when necessary. I’m not going to even think about cacti and succulents in what follows – their drought-resistance is already well-known and I can’t grow them outside during my garden’s winter!
If you are shopping for plants and find yourself attracted to an unknown specimen in a garden centre, looking carefully at the foliage can give you fantastic clues as to its drought-tolerance. Since the two categories of leaf type I mention below occur in Mediterranean regions, cold mountain areas and windy coastlines, there should be something for every French garden.
The most obvious clue is grey and hairy/felted foliage. All grey-leaved plants have hairs over the surface of the leaf (sometimes, as in the delicious Lotus berthelotii, these are so tiny as to be almost invisible to the naked eye).
These hairs reflect heat and also trap moisture in the region of the leaf surface, helping to reduce transpiration, or the plant’s loss of water through its leaves. All of those much-loved greys – lavenders, cotton lavender, artemesias and salvias – are therefore highly drought-resistant (if not always cold-resistant).
The second class of plant that is automatically recognisable as ‘water-wise’ is the vast group that has narrow, evergreen leaves. Think all of the pines and junipers. The grey or blue foliage of the prostrate types of juniper make particularly fine groundcover in hot, dry gardens – coupled with small pines such as Pinus mugo (from the European mountains) you have quite a flashy planting scheme.
If you think hard, there is another surprise class of plant that belongs in this group – grasses! These are my ‘go-to’ drought-beaters here in Lorraine. Treat yourself to a few next spring: steely grey Helictotrichon, the bronzes, greens, greys, yellows and stripes of Miscanthus and Calamagrostis, or the pinky-fawn plumes of Stipa.
November is a great time for planting trees and shrubs – avoid planting grasses until the spring. While the ground is relatively warm and moist the roots will get a head start on 2019 and have built up some strength to face a new season of (we imagine) more sun and drought.
November is also a good time to be planning drought-beating mulches for 2019. Leafmould is a fabulous mulch if you have deciduous trees. Create a wire cage in an out of the way corner of the garden and pile your leaves into it, to stop them blowing about while they rot down.
As to watering, my advice is about eight litres per tree or shrub, once a week – you have to get the new plant to look after itself, rather than become dependent on you and your hose or watering can.
Liquidambar styraciflua, American Sweet Gum for its wonderful autumn colour. Lagerstroemia indica, Crape Myrtle, for its vase shape and purple, blue summer blooms. Vitex agnus-castus, for late summer spikes of blue. Cercis siliquastrum, the Judas tree, for the pink flowers direct from bare bark in spring. Ginkgo biloba, for its leaf shape and autumn colours.
I’m in love with blue flowers and so I’d include Indigofera heterantha, Perovskia atriplicifolia and Caryopteris x clandonensis. Try also the smoke bushes, or Cotinus coggygria – though luscious purple-leaved forms such as ‘Grace’ or ‘Royal Purple’ tolerate dry conditions less than the green forms.
TIP FOR THE MONTH
Don’t forget to get those tulips into the ground. If mulching, make sure that borders are tidied and tulips planted in advance of putting down that cosy winter blanket.
OVER TO YOU
What were your experiences of this summer’s drought? Email me at: firstname.lastname@example.org