When I was a kid Dad would take cuttings from old fruit trees found on his travels and come home with sticks of wood that he would whittle away at with his pocket knife and tape onto trees in our orchard. As if by magic a single tree would start producing all sorts of different fruit as the grafts took and grew.
I had my first go at grafting trees last year in an effort to save a very rare old pink gage plum tree. Encouraged by my results, this year I’ve grafted some wood from an 80 year old prune plum tree in Murchison as well as a few apricots that will do better on a myrobalum rootstock in our heavy clay soil.
So what is grafting?
Grafting is basically splicing a bit of one tree onto another tree. If you line up the layers of the bark correctly, the sap from the living tree flows into the grafted wood like blood, forcing it to grow. After a couple of years growth it can be hard to tell where the two were joined at all.
It is done to grow fruit trees on rootstocks that give the final tree certain characteristics – eg. dwarf trees or clay tolerant trees. It is also done to grow pollinating varieties of fruit on the one tree or simply to save space.
And if it is an old tree that is no longer commercially available, taking some wood to graft onto another tree or rootstock is likely to be your only means of getting hold of one.
Grafting isn’t that difficult. The most important thing is to collect your graft wood in winter and store it in the fridge wrapped in damp paper towels in a sealed bag. Then do the grafting in Spring when the sap is starting to rise.
How to graft your own trees
- Collect your wood for grafting in winter when the tree is dormant. Try and select one year old wood around as thick as your finger. Old wood can be hard to work and can be less vigorous than new growth.
- Store your wood in damp paper towels in a sealed plastic bag in the fridge over winter so it does not dry out.
- If you want to graft onto a rootstock do some homework about what goes with what – for apples M793 is a good robust rootstock, for plums and stone fruit we recommend Myrobalum rootstocks
- Come Spring, when the sap is rising, chop the top off your rootstock where the diameter of it’s trunk is a good match for the diameter of your graft wood. If you get nice small rootstocks this can be quite close to the ground which is good – you don’t want a lot of rootstock trunk left to sprout branches from
- Push your grafting knife blade down into the rootstock to the depth of the top of the blade. This takes a surprising amount of pressure and you can easily overdo it and split your rootstock in half if you’re not careful. Slow and steady pressure with your thumb on top of the blade and a gentle rocking motion does the job – practice on something that isn’t your rootstock if you only have one or two
- If you’re grafting straight onto an existing tree just follow the same steps above as if it was a rootstock – find a branch the same diameter, make a slit in it
- Take your graft wood from the fridge and chop it into short lengths with a couple of buds on each piece – you don’t want to make your bits of graft wood too long as the rootstock won’t have enough puff to bring big bits of wood back to life.
- Be careful with the buds as they are your new growth – don’t squash them with your fingers or knock them off and take note of which way up they are pointing – you don’t want to put your graft wood in upside down.
- Using a sharp grafting knife or pocket knife whittle both sides of your piece of graft wood down into a fine flat tounge. Point the blade away from you as you work and have a few practice runs on not so precious wood to get the hang of it
- Try and get good clean strokes that leave nice clean bark layers as these will knit together well with the bark layers on the rootstock
- Using the tip of the grafting knife gently prise the slit in the rootstock open and carefully and gently push your graft wood down into the slit until you reach the top of your taper. If the two pieces of wood are different widths make sure the bark layers line up on at least one side – it is that light green cambium layer that you want to join up
- Once the graft is in place don’t knock it or move it around
- Wrap the graft gently but firmly along the length of the graft, enclosing the top and the bottom, in buddy tape which will protect the graft, keeping air and dirt out. Buddy tape or grafting tape has a lot of give in it so it lets the sap flow and the graft grow.
- Carefully put a dab of grafting wax on the top of your graft to stop the wood drying out and smear the outside of the grafting tape with wax too.
- Only wax your grafts after they’re all sealed up in tape as if you get wax on your fingers or on the bark layers the grafts won’t take.
- Put a tag on your tree so you remember what it is as they all look the same
- Keep the water up to the grafted trees during the first summer
- Rub any buds off the rootstock that form below the graft – you want all the energy from the rootstock to push into the buds in the graft wood
- If you need to move the tree to plant it in it’s final destination you can do that in the following winter once the new graft growth has dropped it’s leaves and gone dormant.
And here’s an update to this blog post – 8 months later, if you’ve done it right here is how your trees should look. They’ve put on about a meters growth over the summer and they’re just starting to lose their leaves. In another month or so they’ll be completely dormant and they can be lifted and planted out.