My reader from a cold climate will have noticed that winter is fast approaching. Even here in the Loire Valley most of the deciduous plants are naked after, in many cases, treating us to a final, fiery display of autumn leaf colour.
Our St. Catherine’s Day Magnolia planting was partly in preparation for this season. It is a far too valuable and beautiful specimen to lose. I have been getting in the ground as much as I can from my last delivery of plants so that they would not be frozen in their pots over winter. The soil acts as an insulator from the cold and, in the case of tender subjects like perennial Salvia uliginosa and Artemisia Powis Castle, I have planted deeply to make the most of this property of the soil.
Some plants have had to stay in pots for the time being. My little collection of winter flowering Camellias has been placed, in cold weather at least, in our unheated and rather leaky, north facing conservatory.
Here too are a pot of Begonia and another of Geraniums, which used to sit outside the door of the Gîte. It will not be the end of the world if they don’t survive the cold but I hope they do.
When the climate dictates I will also move the Tree Fern under cover joining the huge pot of Christmas Cactus which will soon be in flower. Eventually this conservatory could be something really special to greet clients and other visitors when they arrive at the front door. At the moment however, most of the space is taken up by office furniture and carpets awaiting a final home, so it rather lets us down.
Our two lemon trees, brought from our home in England at great trouble and expense, have been treated to a pair of fleece covers with which they have been enveloped for some time now. This allows rain and some light through, but allegedly protects them from the worst of the frost and cold winds. These plants have not had a comfortable life since being turned out of their lovely conservatory in Bedfordshire and dragged, kicking and screaming, to this country. It’s sad to see them suffer but in the fullness of time a home will be found for them in the new office building: when we finally get ‘round to building it.
Other plants are dotted around the garden waiting for me to dig a bed to accommodate them. These will have to deal with the cold as best they can but the wet is equally a factor in winter plant loses. I have ensured that these pots do not sit on the ground in such a way as to become waterlogged. It is for this reason that when filling a tub or other display container you must add gravel, crocks or other materials inside to keep the drainage holes clear. It is also worth considering raising the pot off the ground during winter to create very free drainage of excess water.
Drainage is an important aspect of the soil as well, but harder to modify. Vulnerable plants can be planted in little mounds of soil to improve drainage, or grit can be added. Underground drainage pipes can be installed in particularly difficult sites but if you garden on heavy clay soil you have to accept that your soil will be cold and damp over winter and plant accordingly. We moved to mid Bedfordshire to escape the clay soil in Harpenden and here in France the soil is wonderful. This will allow us to over-winter plants not dreamed of in our earlier gardens.
We have two enormous Sequoias in our property, as our regular reader will remember. These give us a few problems, but three great benefits: the dappled shade they provide is ideal for woodland plants and we have created an oriental style garden of Camellias, Rhododendrons, Hamamelis, Japanese Maples and other plants here; the soil nearby is dry, supporting plants which need to keep their roots this way and the overhanging branches act as protection from the frost. Consider placing your own frost-tender plants in the shade of a tree over winter.
We have tried one other trick this year to protect some tender plants from the cold. I sowed seeds of Californian Poppies, collected from plants flowering in the garden, around a clump of Salvia argentea hoping that they would act as a barrier to the cold and keep the soil a little drier. I did the same for newly planted Euphorbia giffithii Fireglow and used Calendula in a similar way elsewhere. It will be interesting to see how this turns out.
In gardens in the village some plants, notably large palms and Oleander, have been wrapped up in bubble plastic, while Arum Lilies have been covered in thick layers of straw mulch. I have noticed a few improvised cloches which shield plants from damp in addition to keeping them warmer – our silver-leaved Salvia would enjoy that sort of protection.
If you must grow tender plants,- and I must even if you don’t – these sort of protective measures will ensure, as much as you can ensure, that your treasures make it through to the next growing season.