I have several hanging baskets of Geraniums that are still outside. I would like to try to keep them until next year. I live in Toronto. Any advice would be greatly appreciated.
There are are a number of ways to over-winter geraniums (Pelargonium) in Toronto’s climate.
This takes the least amount of space, and can increase your stock of plants, although the plants themselves won’t be as large as the originals at the start of the new season.
Cut a 3-4″ long tip of a healthy growing stem just below a leaf node (where the leaf grows from the stem). Remove all but the top two or three leaves and any flowers or flower buds. This is usually done in September, but can be successful as long as the plant itself is healthy. You can dip the cut end of the stem in a rooting hormone but, again, this isn’t essential to success.
Put the cut end into a well-drained potting medium (often called “potting soil” although it doesn’t contain any actual soil). A 4″ pot will be enough for up to 4 cuttings. Then place the pot in a bright window. Water when soil appears dry. If the plant remains green, it will likely have rooted.
In fact, you can also simply place the cuttings, prepared as above, into an opaque container of water. Roots will emerge after a few weeks, and then you can pot the cuttings up.
Store in original container:
If you have plenty of space and a bright, cool window, you can bring your plants indoors in their original pots. Cut the plants back by half to keep them compact (you can treat some of the off-cuts as above if you want more plants). Expect to lose some leaves due to the change in growing conditions. Water them occasionally, but not until the soil looks dry. In late February, as daylight increases, you can begin to fertilize with a one-quarter-strength liquid fertilizer.
Store in paper:
Unpot your plants and shake the soil off the roots. Wrap them in newspaper — some people also place the wrapped geraniums inside a cardboard box. Place the wrapped plants in a cool (not freezing) room. A couple of times during the winter, inspect the plants. You can give the roots a good soaking at these times, and discard any stems that have clearly become too dry.
Pelargoniums – which are really tender perennials that Canadians treat as annuals – are remarkably resilient. With very little effort, you can keep them from year to year.
Further information can be found at this link:
Good luck with your geraniums!