I used to save quite a few plants through the winter. I had dreams of plants that would be more grand and beautiful with each passing year. Well, overwintering isn’t always as easy as it looks. In some cases, there are pests to contend with. My Meyer lemon tree was constantly plagued by scale insects. Bulbs and tubers can be tricky, especially if they are finicky about moisture levels.
These days, I save fewer plants, choosing the ones that can wait out the winter with little help from me. Here are my winners:
Cannas: I have a couple of special ones that I save every year. I’m especially fond of a variety called Panache, which has peachy, orchid-like flowers. Overwintering is super-simple. Once the foliage has been blackened by a few frosts, I cut the stems to about six inches and dig the clumps, dumping the whole thing—soil and all—into a large nursery pot. I move the pot into my cool basement, where the clump sits in the dark for the winter. I water the pot a few times during the winter, keeping it barely moist. In March, I repot divisions from the original the clump.
Bananas: These are easy, too. They get the same treatment as the cannas. The exception is that I leave the stems (or trunks) pretty long, just cutting away the frost-killed leaves.
Hydrangeas: In general, the mophead and lacecap varieties are not hardy up here in zone 5. The plants may survive, but the buds get killed off. So, long before the days of Endless Summer, the reliable blue hydrangea for the north, I collected a half-dozen Hydrangea macrophylla and H. serrata. Varieties include Blue Billow, Sister Theresa, Pink Beauty and Nikko Blue. I grow them in large, self-watering pots and move them to the dark basement for the winter. The pots are heavy, but the beautiful blooms make it worth the effort.
A few years ago, I added a crape myrtle to the collection. It has grown well, and the bark started exfoliating this year. The fall color is marvelous. Still, it’s never bloomed.
Lotus: Even if it only blooms once a summer, this flower is a stunner. The foliage is striking, too. The tuber and roots are planted in a plastic tub that sits in a glazed ceramic pot. Once the water starts freezing in the fall, I lift the tub and move it to the basement. There it remains until spring. As long as the soil is covered with a couple inches of water, the plant is fine.
Last winter, I overwintered a couple new tender varieties: pitcher plant (Sarracenia) and Mystic Blue Spires salvia (Salvia ‘Mystic Blue Spires’). Both came through fine. This year, I’m going to attempt overwintering some kalanchoe that have spent the summer in my rock garden.