Grafting Avocados
by Neil Barraclough and Paul Winfield
Optimal time for grafting is late December through to March in S.E, Australia.
What you will need: Gather secateurs, grafting knife, grafting mastic, grafting tape, "Buddy Tape" (TM), a small spray bottle with 70% alcohol and possibly a clothes peg. The cheap plastic Stanley knives are OK for the softer wood with avocados and we are experimenting with success using Vaseline as a grafting mastic. The 70% alcohol solution is used to sterilize equipment to avoid spreading disease and killing fungi and bacteria that can kill the graft. Mix 80% methylated spirits with 20% very clean water. |
Rootstock:
Select your avocado seedlings to be grafted. If potting up ones that have come up in the compost, do it at least a month before grafting and give them a modest nitrogen boost a couple of times prior to grafting. Ideally choose young plants that are pencil thickness, with actively growing young wood.
Collecting scion:
Sterilize your secateurs with the 70% alcohol prior to collecting scion. Select the young wood and take the entire section with healthy buds in the section where the leaf joins the stem.
We are experimenting with misting the scion with 70% alcohol as we take it, then place in an airtight plastic bag. The larger press-seal bags are ideal. Ideally minimise the time between collecting scion and grafting. Store it in the fridge till needed. Avocado scion can be sent through the mail if needed.
Select your avocado seedlings to be grafted. If potting up ones that have come up in the compost, do it at least a month before grafting and give them a modest nitrogen boost a couple of times prior to grafting. Ideally choose young plants that are pencil thickness, with actively growing young wood.
Collecting scion:
Sterilize your secateurs with the 70% alcohol prior to collecting scion. Select the young wood and take the entire section with healthy buds in the section where the leaf joins the stem.
- Ideally the scion should be similar thickness to the rootstock at the point where it is intended to graft. A range of thicknesses may allow the grafter to select a place on the rootstock where the cambium layer can be aligned on both sides. Larger scion tends to be more successful than smaller scion.
We are experimenting with misting the scion with 70% alcohol as we take it, then place in an airtight plastic bag. The larger press-seal bags are ideal. Ideally minimise the time between collecting scion and grafting. Store it in the fridge till needed. Avocado scion can be sent through the mail if needed.
Grafting:
Select a healthy bud and graft it on to the rootstock with either a whip and tongue graft, a cleft (wedge) or bark graft depending on your preference or the situation.
Whip and tongue grafts haven’t been traditionally recommended because the softer wood makes it harder to hold together to tape, but whip and tongues can be done with care. Or you may like to try a clothes peg on top of the graft until the bottom has been taped.
For smaller seedlings, wedge grafts are easiest to do.
If scion is significantly smaller than root stock, a bark graft is easiest to do.
Select a healthy bud and graft it on to the rootstock with either a whip and tongue graft, a cleft (wedge) or bark graft depending on your preference or the situation.
Whip and tongue grafts haven’t been traditionally recommended because the softer wood makes it harder to hold together to tape, but whip and tongues can be done with care. Or you may like to try a clothes peg on top of the graft until the bottom has been taped.
For smaller seedlings, wedge grafts are easiest to do.
If scion is significantly smaller than root stock, a bark graft is easiest to do.
Cover the cut section of the scion with mastic or Vaseline. We are trialling Vaseline because it is cheaper and more readily available. Spray-mist the scion above the grafting tape with a 70% alcohol solution, and tape over the entire section above the grafting tape with buddy tape, with only a single layer tightly stretched covering the bud. .
Taking care of the grafted plant:
After care is very important. Keep the grafted plant warm and well-watered. Apply regular light nitrogen and complete fertilizer applications with environmentally sourced fish meal or sea weed products.
Keep grafted plants in the shade or low light conditions while grafts are "taking". Success rates are typically 60-70%. If successful the shoot will grow through the tightly stretched buddy tape - there is no need to remove the buddy tape. However the grafting tape used to tape the graft may need to be removed to avoid choking the growing scion.
If grafting onto an established tree, cut back the tree hard to promote new growth and graft onto new growth once big enough.
Video:
Thanks Mick Donelly for this video. Unfortunately during the second graft when I used cling wrap rather than buddy tape I forgot to mist the graft with 70% alcohol.
The authors have prepared this for a number of reasons, including our passion for home growers to experience the pleasure of doing as much of the process as they can. We encourage people to check for seedling avocados in their locality, as these may be more locally adapted. If you find one, propagate from it and share it around amongst your friends. If you have any questions or can share a “find” of a great seedling avocado, contact the authors.
Social Media:
Heritage and Rare Fruit Network (Australia)
Heritage and Rare Fruit Network Tasmania
Heritage and Rare Fruit Network NSW
After care is very important. Keep the grafted plant warm and well-watered. Apply regular light nitrogen and complete fertilizer applications with environmentally sourced fish meal or sea weed products.
Keep grafted plants in the shade or low light conditions while grafts are "taking". Success rates are typically 60-70%. If successful the shoot will grow through the tightly stretched buddy tape - there is no need to remove the buddy tape. However the grafting tape used to tape the graft may need to be removed to avoid choking the growing scion.
If grafting onto an established tree, cut back the tree hard to promote new growth and graft onto new growth once big enough.
Video:
Thanks Mick Donelly for this video. Unfortunately during the second graft when I used cling wrap rather than buddy tape I forgot to mist the graft with 70% alcohol.
The authors have prepared this for a number of reasons, including our passion for home growers to experience the pleasure of doing as much of the process as they can. We encourage people to check for seedling avocados in their locality, as these may be more locally adapted. If you find one, propagate from it and share it around amongst your friends. If you have any questions or can share a “find” of a great seedling avocado, contact the authors.
Social Media:
Heritage and Rare Fruit Network (Australia)
Heritage and Rare Fruit Network Tasmania
Heritage and Rare Fruit Network NSW