Grafting timing


Hi. I have a small field apple that I collected from a cow pasture to create into a bonsai tree. It doesn’t flower at all so I want to graft crab apple scions onto it to see if they take or not. If they do then I would ultimately remove the field apple branches and allow the crabapple branches to develop.
My question is when is the time to do this? I would think spring but read some stuff online and am now totally confused. Also, is there a width to the scion that is ideal?
Love to know your thoughts.



Thank you for contacting the Toronto Master Gardeners with your question about your interesting crab apple grafting / bonsai project. This grafting is best done in the spring just as growth starts, when the weather has warmed up but it’s not hot yet. The buds on the scion must still be dormant, and the sap in the rootstock just starting to flow. This timing means that after grafting the scion will start to come out of dormancy as it is exposed to warmer air, and as it does it will have access to the flowing sap in the rootstock, so the graft will start to form immediately and the scion will have less time in which to dry out. In Toronto the ideal time for this grafting would be late April – early May, assuming that we don’t have an abnormally hot spring.

It is important that the buds on the scion still be dormant when this grafting is done. Typically the scions are collected in Feb – early March in our climate, then put in a large polyethylene bag with a slightly damp paper towel or wood shavings or sphagnum moss, and stored in a refrigerator at normal refrigerator temperature for 1-2 months before grafting.  Note that storing the scions with apples should be avoided since apples emit ethylene gas that can damage them. Scions are usually about 12-18” long and about the same diameter as the rootstock (usually about the diameter of a pencil). They should be year-old wood with vegetative not floral buds.

Here is a link to a website from the University of Missouri with information about collecting scions :

Here is a link from the Ontario Ministry of Agriculture, Food and Rural Affairs with information about different grafting techniques that might be helpful :

Good luck with your grafting !