Can you ever remember a March like this one? Forget the lion, this one came in like a playful little kitten who scratched for a couple of days then settled in on being cute and cuddly. Because of my location, I tend to be quite a bit behind everyone else in the Spring. My snowdrops, witch hazel and some pansies I planted last Fall have just started to bloom. However, I was at a friend’s house last weekend for lunch and she had dwarf irises starting to bloom. Looking at the long range forecast, there doesn’t seem to be an end to these higher temperatures.
Of course, with this warm weather, everyone’s itching to get out into the garden. I know you are, because you’re starting to call about plants…even annuals. I’ve had three calls about annuals in the past week – and it’s only mid-March. My advice to you is to enjoy this beautiful weather, get some chores done in the garden, and think about what you’d like to do this year. Leave the planting for a month or so, and leave the annuals (other than pansies) for quite a while yet.
So what can you do in the garden at the moment? There’s raking, cutting back your perennials, pruning, pushing the odd plant back in the ground, and weeding. This is a great time to get your weeding done. There’s a short period, right after the frost has come out of the ground, when even the most stubborn weed will just pop right out with almost no effort. The same goes for some of the perennials, so be careful what you tug at and with your rakes and cultivators. If you have plants that are protected for the winter, it might be a good idea to leave them be for now. We could very likely still get some winter weather, despite the fact that my nephew was wearing shorts yesterday. I recently read that 15% of Toronto’s snowfall occurs after March 11 and we’re North of Toronto.
While working in the garden, it’s handy to have some long boards available, like a 2×8 or a 2×4 if you do yoga and your balance is better than mine. Lay these down and use them to step on. They’ll distribute your weight more evenly so you don’t compact the wet soil.
When it comes to pruning shrubs and cutting back perennials, I’m afraid there is no all-inclusive rule. There are generalizations and guidelines, but for these there are always exceptions. With the shrubs, if it flowers between now and early June, you should wait to prune it until after it has bloomed. Otherwise, you may be sacrificing your blooms for this year. You can still remove obviously dead wood, though. If you’ve protected it for the winter, I’d wait another month yet before pruning. If it’s a plant with sap that runs freely in the Spring, like maples, they should really be pruned in the fall, but if you really want/need to prune it this year, wait another month. This is also a good time to apply a dormant oil spray. With the lower than normal temperatures this winter, I’m expecting a bumper crop of bugs this year and dormant oil can reduce their numbers substantially. Dormant oil should be sprayed on a dry day, with the temperature being somewhere between 10-20ºC, and when we aren’t expecting a freeze within 24 hours.
With perennials, almost all of them can be cut back now and most can be cut down to the ground. Grasses are one group where there are some exceptions. Cool season grasses are the ones that start growing right away, the most common one being Calamagrostis, or feather reed grass. It’s the grass that looks like wheat in the middle of summer and is usually strictly upright. Cool season grasses should be cut down close to the ground now, before they start growing. Warm season grasses don’t like frost and will wait to start growing until much later in the season, some as late as June. If you cut these back now, leave about six inches of last year’s growth to protect the crown from hard frosts. If you wait until mid-May, you can cut them down close to the ground. Russian sage and butterfly bush are others that you don’t want to cut right down to the ground. Leave about six to nine inches of the woody stem from last year.
In the coming weeks, keep an eye on any shrubs and perennials that are breaking dormancy extra early this year. If we get a cold snap, which is likely, these can be damaged and that damage could be severe this year. Throw a blanket over them (if possible) on the nights when the temperature drops below freezing and cover sensitive plants, like hostas, with plastic to protect them from frost. A little prevention should keep March from going out like a lamb to the slaughter.