Here’s what you need to know to successfully transplant plants in the fall garden.
First though, you have to appreciate the fall. September is a glorious gardening month for me. Love it. Kids go back to school, Doug goes back into the garden because of cooler working temperatures and the need to work off some of that hot-weather-beer. 😉
Video: Fall Garden Preparation Tips
Questions About Transplanting In The Fall
If you’re in a USDA zone 4-5 garden then there are some rules of thumb to think about. These are for “average best survival” and have been worked out over many years and literally hundreds of thousands of plants.
And before you ask – yes, you can break these rules and get away with it and many of you do. But in the nursery business, a percentage or two increase in survival rates means more money in the bank so I pay attention to this (because without a nursery, I hate having to pay to replace expensive plants.)
Another question – if your garden is warmer than zone 5 – you can back this entire thing up by a week for every zone. So zone 7 gets an extra three weeks of added survival over my timing.
NOTE an important point here – dormancy is not only a function of temperature but also one of lowering light levels. If you’re watching the trees, many are starting to show signs of fall colour. It’s not low temperatures doing this but rather shorter days are kicking the plants into dormancy.
What Do I Move In September?
The month of September is for moving perennials. And yes, I will have every perennial I’m going to move dug and moved in the next month. I will then stop moving perennials because (depending on the temperatures) they may or may not have enough time to set good roots.
Yes, some of them are looking really good right now and yes, I do whack them back anyway and dig. This does mean sacrificing flowers for next year’s growth and I’m good with that.
Yes, you can move them later with success but September is the optimum month.
A Clarification About Timing
As you’re reading this remember the point I made above. These guidelines are for a USDA 4. For every zone warmer you are – delay this by one week.
So a USDA 6 would start transplanting perennials in mid-September rather than early September and would go until mid-October instead of late September. (two week difference between zone 4 and zone 6).
October Brings The Evergreens
The month of October is for evergreen shrubs. I’ll have them all moved (and I do have a few this year) in middle to end of October.
You can (and likely should) spray them with an antidesiccant before you move them to stop any moisture loss. (I do)
What To Wait For In October and November
The month of October and into November is for woody plants (shrubs and trees that drop their leaves) and I can do those as long as the ground isn’t frozen.
The marker here is as soon as the leaves start to turn their fall colours (or drop off) the plant is ready to be moved.
Or, If You’re Too Busy
Water your fall transplants very well for the first month after transplanting. We want them happy and not water starved.
And like spring transplanting, do NOT feed or add anything to the planting holes when you move them.