Late winter and early spring is the ideal time to graft a compatible variety onto an established citrus tree as the sap is flowing and the bark slips more easily to allow grafting.
Expand the varieties on your established citrus by grafting another variety onto it. Not only does this give you different fruit over the year but also saves space in a smaller garden.
Generally only species that belong to the same Genus can be grafted. Any members of the citrus family can be grafted onto a good citrus rootstock and produce fruit.
Avid gardener Joe has bark grafted a Meyer lemon scion onto a branch of a large established grapefruit tree and shares the procedure with us in this tutorial. He has used equipment found around the home to do his grafting, so you can begin experimenting without the expense of new equipment if you use a little care. This is part Joe’s approach to sustainable gardening.
To begin, sterilise the pruning and grafting equipment with a solution of 1 part household bleach to 3 parts water.
The scion should be 100 – 150mm long with 3-6 buds. They should come from 1 year old wood of about 5-7mm in diameter and can be cut and stored wrapped in moist kitchen paper in a plastic bag in the fridge (not freezer) until needed.
Choose branch to graft onto at around 100 -120 cm from the ground. It should be about 45 – 50 mm in diameter. Make a clean, smooth cut at a right angle to the branch that you have selected.
Then, use a grafting knife or other sharp knife to score the bark. In this case Joe used a small, sharp chisel to score the bark to the width of the scion he was using. He made 2 vertical cuts 5 mm apart and to the depth of the bark. The length of the parallel cuts were 25 mm long.
Carefully ease back the bark strip exposing the cambian layer below, being careful to not detatch the bark strip completely.
Remove any shavings made by easing back the bark so that there is a smooth surface for the cambium union.
Prepare the scion to be grafted. Using a grafting knife or sharp chisel, cut a wedge at the end of the scion to allow the scion to fit into the bottom of the bark snuggly.
Turn the scion over and cut off the surface to expose the cambian on the scion to the length and width of the cut on the branch. Do this on the side with the lowest bud.
Cut a wedge at the end to to complete the wedge shape that will allow the scion to fit into the bottom of the bark.
Push the wedge shaped and prepared scion into the bark, with the long exposed cut of the scion placed directly onto the cambium of the branch. Make sure that the cambium of both the scion and the prepared branch are fully in contact and that the wedge is as far down as possible.
Secure with an elastic band while cutting a piece of grafting tape or gaffer tape as Joe has used.
Secure the graft tightly with the tape so that the cambium of both the branch and the scion are in full contact.
Trim the scion and remove any leaves.
You can make other graft to the branch at other points. Joe has made 3 grafts to his chosen branch.)Remember to clean your equiment at each grafting.
When all the grafts have been made to the branch, use a long strip of plastic to firmly hold the grafts to the branch.
Cover the cut end completely with wide tape.
Then cover firmly this with the plastic strip
Tie the plastic strip and elastic band to hold it in place.
Cover the ends of the scions with tape.
Place a plastic bag over the entire graft and secure.
Cover the whole plastic covered graft with some newspaper and secure with garden twine. This will protect the graft from the sun and wind.
Finally, tie back the ends of the newspaper. Make sure to keep the tree well watered during the hot months to protect the newly made grafts.
Four months later, after surviving the extreme heat of summer Joe unwrapped the newspaper to show that the grafts had taken.
At six months the grafts were in leaf and flower and have been doing well since. One of the grafts failed but two of three survived. Its a pleasing result.
If you have an established citrus its well worth the effort to try your hand at grafting. With a little care and patience you can add another variety without needing the extra garden space for a new tree. Its spring in Sydney and the perfect time for experimenting with grafting. Why not try it for yourself.
Update July 2020:
Here are some lemons harvested from the graft. Two beautiful Meyer lemons.
Update December 2020:
Here is the graft still going well even after the harsh summer earlier in the year and a new lemon is coming along.