Many of us in our area are still mourning the close of Blue Meadow Farm, a nursery that sold so many wonderful annuals and tender perennials as well as their sturdier relatives. Now they have come out with a beautiful and useful book published by Storey about overwintering all kinds of tender plants including bulbs and tubers.
The book begins with a general discussion about gardening with tender perennials, both in the garden and in containers.
The second section gives general information about the different requirements of various plants when they are brought to overwinter in the house. Some plants will be happy socializing with you in front of a window all winter long. Plants that propagate themselves by corms or tubers will need storage in the basement.
Recently I’ve had a number of people talk to me about the difficulty of overwintering dahlia tubers. It’s not that it is so difficult and, of course, for every dahlia tuber you plant you will dig up several in the fall. Some people find that the digging up is the hard part, but the McGowans give direction from digging up the tubers, trimming off all the herbaceous growth, letting the tubers cure for a couple of days and then placing them in damp (be careful its not wet) peat moss in a container that will not allow any light. It can be as simple as a black plastic bag. Then the container can be stored in a cool dark place like a cellar, or closet where the temperature will not go above 50 degrees. Of course, temperatures can’t go below 35 degrees, either. It is always wise to check the dahlia tubers periodically to make sure the peat moss isn’t drying out and that the tubers aren’t rotting.
Some corms, like those for gladiolas need to be kept dark and dry. The temperature requirements are the same, but the bulbs can be stored in a paper bag or onion mesh sack.
Happily some plants can overwinter by a window and keep us company. I have brought in my rosemary plant and kept it alive for many years. Actually, I really had to give it up when it just got too big to handle. I have a new small plant this year. The McGowans list more varieties of rosemary than I ever heard of. Rosemary is a Mediterranean plant and while it is not hardy it prefers cool temperatures, as low as 30 degrees, indoors. There is a warning about overwatering, but from my own experience I know this does not mean cutting down drastically on watering. Our houses are so dry in winter, even in the cool rooms.
Although others have been able to grow lavender in Heath, I’ve never been successful. I never thought of growing it in a pot and bringing it indoors for the winter where a cool bright spot will keep it going all winter long.
One of the worries of overwintering plants is the dangers of disease or pests. The McGowans give comprehensive advice on dealing with both of these, beginning with the need to take care when bringing plants in from outside.
The first two sections of the book are wonderfully illustrated with some photographs, but also many delightful watercolors by Beverly Duncan of Ashfield who is known for her precise botanical drawings.
More than half the book is given over to descriptions of individual plants, with a photograph for each. Hardiness is given, names of the McGowans’ favorite cultivars, ways to combine certain plants along with how to overwinter and how to propagate. Most of us will pay particular attention to the notes about pest susceptibility.
The McGowans also give good advice about that transitional period in the spring when the days are longer, the sun is brighter and we are all eager to get back outside. Some plants will need to be trimmed back, corms and tubers will need potting up, and spring is the ideal time for taking cuttings. Directions for propagating more plants by softwood cuttings or leaf cuttings are given clearly and succinctly.
The book is as tempting as a walk through the Blue Meadow aisles. I can imagine many of us making up a list of plants we must have! Fortunately, the McGowans have anticipated this reaction and have included a list of nurseries where plants and seeds can be obtained.