Grafting: Techniques for Successful Plant Grafting in NZ

Introduction to Grafting

Grafting is a gardening technique where parts from two different plants are joined together so they grow as one. It helps gardeners mix the best features of different plants, like better disease resistance, higher productivity, or the ability to grow in tough conditions. This guide will explain everything about grafting, including the different types, tools you need, choosing rootstock, and grafting methods for New Zealand gardens.

Grafting is used in many types of plants, including fruit trees, ornamental trees, and flowering shrubs. It’s a great way to help plants grow in areas where they might not thrive naturally, and it can also help produce fruit or flowers that are bigger, tastier, or more colorful. By understanding how grafting works, gardeners can improve their gardens and make the most out of their plants. This guide will help you learn about the different types of grafting and how you can use them to improve your garden.

Why Grafting is Important

Grafting has many benefits. It helps fruit trees grow better, combines the best traits of different plants, and helps trees handle difficult soil or weather. Grafting is also helpful for growing new plants, especially for types that don’t grow well from seeds or cuttings. By joining a scion (a piece of the plant with desired traits) to a rootstock (the part with the root system), grafting lets gardeners get the traits they want in one plant more quickly.

Grafting is especially important for fruit trees. Many popular fruit varieties do not grow true to type from seed, meaning that if you plant a seed from an apple, the resulting tree may not produce the same kind of apples. Grafting solves this problem by allowing gardeners to grow exact copies of the fruit they want. Grafting can also help make plants more resistant to diseases, which is especially useful in areas where certain plant diseases are common.

Types of Grafting Techniques

Whip and Tongue Grafting Whip and tongue grafting is often used for fruit trees. It involves making a slanted cut on both the rootstock and scion, then cutting a “tongue” on each to fit them together better. This method gives a larger contact area, which helps the graft heal faster. It is usually done in late winter to early spring. The whip and tongue method is one of the most reliable grafting techniques for beginners. It creates a strong bond between the scion and rootstock, which helps the graft heal quickly and successfully. It’s important to make sure the cuts are clean and the cambium layers (the green part just under the bark) are properly aligned, as this is where the healing process happens.
Cleft Grafting Cleft grafting is used to join a scion to a larger rootstock branch. A cut is made in the rootstock, and the scion is placed inside it. This method is good for giving old trees new life or changing the variety of an older tree. It is best done in late winter when the tree is dormant. Cleft grafting is often used when you want to add new branches to an older tree or when you want to grow multiple varieties on a single tree. This is a great way to create a tree that produces different types of fruit, such as a “fruit salad” tree that has apples, pears, and plums all growing on the same tree. It’s important to use healthy scion wood and make sure the cuts are clean and fit tightly.
Budding (Bud Grafting) Budding involves grafting a single bud onto the rootstock. In T-budding, a “T” shaped cut is made in the rootstock, and a bud from the desired plant is inserted. This method is common for fruit trees, roses, and ornamental plants and is usually done in late summer. Bud grafting is a very efficient way to graft because it uses less plant material than other methods. It’s also a good way to graft many plants at once, especially if you’re working with limited scion material. Budding is often used for roses and other flowering plants to help create new varieties with beautiful flowers. The success of budding depends on making sure the bark is “slipping,” meaning it can easily be peeled back without damaging the cambium.
Bridge Grafting Bridge grafting is used to fix damaged trees, like when animals strip away bark. It involves grafting scions above and below the damaged area to “bridge” it, allowing nutrients to flow and helping the tree heal. This type of grafting is especially useful for saving trees that have been damaged by pests or accidents. When bark is stripped away from a tree, it can interrupt the flow of nutrients and water, which can eventually kill the tree. By bridging the damaged area, you create a way for the nutrients to keep flowing, which helps the tree recover. It’s important to use several scions to make sure the graft is strong enough to support the tree’s growth.
Approach Grafting Approach grafting is done when both the rootstock and scion are still attached to their original plants during the grafting. This method is used for plants that are hard to graft, allowing both parts to keep getting nutrients until the graft is successful. Approach grafting is often used for plants that are difficult to graft using other methods, such as certain ornamental trees or plants that are sensitive to changes. Since both the rootstock and scion remain attached to their own root systems, they continue to get the nutrients they need until the graft takes. Once the graft is successful, the scion is cut from its original root system.

Tools and Materials Needed for Grafting

To graft successfully, you will need:

Sharp Grafting Knife: A sharp knife makes clean cuts, which are important for a good graft.
Grafting Tape or Rubber Bands: These hold the graft in place while it heals.
Grafting Wax: Wax seals the graft to keep moisture in and protect from pests and diseases.
Pruners: Used to trim the scion and rootstock.
Rootstock and Scion: Choosing compatible plants is very important for a successful graft.

It’s also helpful to have a sterilizing solution, such as rubbing alcohol, to keep your tools clean. This helps prevent the spread of diseases, which is especially important when grafting multiple plants. Having a clean working area and the right materials can make a big difference in the success of your grafts.

Choosing the Right Rootstock

Choosing the right rootstock is one of the most important steps in grafting. The rootstock affects the plant’s growth, disease resistance, and how well it adapts to the soil. In New Zealand, common rootstocks for fruit trees include:

Apple (Malus domestica): MM106 and M9 are popular for apples. MM106 is semi-dwarfing and works in many soil types, while M9 is dwarfing and good for smaller spaces.
Citrus (Citrus spp.): Trifoliate orange (Poncirus trifoliata) is often used for citrus, giving good cold tolerance.
Stone Fruit (Prunus spp.): Plum rootstocks are used for cherries, peaches, and nectarines because they offer good disease resistance.

The right rootstock can help make the plant more adaptable to the conditions in your garden, such as soil type and climate. For example, using a dwarfing rootstock can help control the size of the tree, which is great for smaller gardens or for growing in containers. Choosing a rootstock that is resistant to diseases common in your area can also help reduce the need for chemical treatments.

When to Graft

Timing is key for successful grafting. In New Zealand, the best time to graft most fruit trees is late winter to early spring, when both the rootstock and scion are dormant but starting to swell with buds. Bud grafting is usually done in late summer when the bark can easily separate from the wood.

The right time to graft can depend on the type of plant and the grafting method. For most grafting techniques, it’s important that the rootstock and scion are in a similar stage of growth, so they are more likely to heal together. Late winter and early spring are usually ideal because the plants are starting to grow again, which helps the graft heal. In summer, budding is more successful because the bark is easier to work with, making it easier to insert the bud.

Step-by-Step Grafting Process

Prepare the Rootstock and Scion: Choose healthy rootstock and scion wood. Make sure the scion has at least 2-3 healthy buds.
Make the Cuts: Make the needed cuts on both the rootstock and scion depending on the grafting method.
Join the Scion and Rootstock: Align the cambium layers (the green part just under the bark) of both the rootstock and scion. This alignment is important for the graft to work.
Secure the Graft: Use grafting tape or rubber bands to hold the graft in place.
Seal the Graft: Apply grafting wax to seal exposed areas and keep moisture in.
Aftercare: Keep the grafted plant in a sheltered spot and give it enough water. Protect it from extreme weather until the graft heals.

Aftercare is very important for a successful graft. The grafted plant should be kept in a sheltered area away from strong winds or extreme temperatures, which could damage the graft. Watering should be done carefully—enough to keep the plant healthy but not so much that it causes the graft to rot. Checking the graft regularly to make sure it’s healing well is also important. If you notice any problems, such as drying out or pests, take action right away to protect the graft.

Common Grafting Challenges and Solutions

Poor Cambium Contact: If the cambium layers don’t align, the graft won’t work. Make sure your cuts and alignment are precise.
Drying Out: Grafts can dry out if not sealed well. Always use grafting wax to seal exposed parts.
Incompatible Rootstock and Scion: Not all plants are compatible. Research plant compatibility before grafting.
Pests and Diseases: New grafts are vulnerable to pests and diseases. Protect the graft area with barriers or fungicides.

Another common challenge is the environment. Grafts need the right conditions to heal, including humidity and temperature. If the air is too dry, the graft can dry out before it has a chance to heal. Using grafting wax and keeping the grafted plant in a humid environment can help prevent drying. In some cases, grafting might not work the first time, but with practice, you’ll get better at making clean cuts and properly aligning the cambium layers.

Grafting Fruit Trees in New Zealand

Grafting fruit trees is popular in New Zealand. Gardeners often graft apples, pears, plums, and citrus to increase yield and adapt to local conditions. Grafting can create trees that produce multiple types of fruit—great for small gardens. For example, an apple tree with different scions can produce several varieties of apples, making the harvest season longer.

Grafting also allows you to grow fruit trees that are better suited to the specific conditions in your garden. For example, if you have heavy clay soil, you can choose a rootstock that is more tolerant of these conditions. Multi-grafted trees are also a great way to save space. Instead of planting several different trees, you can have one tree that produces different kinds of fruit. This is especially useful in urban gardens where space is limited.

Tips for Successful Grafting

Start with Easy Plants: If you’re new to grafting, start with easy plants like apples, which are more likely to succeed.
Keep Tools Clean: Sterilize your tools before use to prevent diseases.
Use Healthy Scion Wood: Take scions from healthy, disease-free plants for the best chance of success.
Be Patient: Grafting takes practice. Don’t be discouraged if your first attempts don’t work—keep trying.
Protect the Graft: Make sure the graft is protected from pests and extreme weather conditions.
Check the Graft Often: Regularly check the graft to make sure it’s healing well. If you see any problems, address them quickly.

Grafting can be a bit challenging at first, but the more you practice, the better you’ll get. Starting with easy plants, like apples, gives you a higher chance of success, which can help you build confidence. Clean tools are also very important—dirty tools can spread disease, which can ruin your grafts. Protecting the graft from pests, such as insects or birds, is also key. You can use netting or other barriers to keep pests away while the graft heals.

Conclusion

Grafting is a powerful gardening method that helps gardeners mix the best traits of different plants, improve fruit production, and adapt plants to specific conditions. Whether you’re grafting fruit trees for a backyard orchard or experimenting with ornamental plants, learning the different grafting techniques and best practices will help you succeed. With time and practice, you can master grafting and enjoy all the benefits it brings to your garden in New Zealand.

Grafting is not just a way to grow new plants—it’s also a way to solve problems in the garden, such as improving plant health, fixing damaged trees, or adapting plants to tough conditions. By understanding the different grafting techniques, the tools and materials needed, and the best times to graft, you can become more skilled at this useful gardening technique. Keep practicing, stay patient, and soon you’ll be creating healthy, productive grafted plants that will thrive in your garden.

For more gardening tips and detailed guides, visit MyGarden.co.nz and start your grafting journey today!

Frequently Asked Questions (FAQs)

What is grafting?
Grafting is a gardening technique where parts from two different plants are joined together to grow as one plant. This involves attaching a scion, which is a piece of a plant with desired characteristics, to a rootstock, which provides the root system. When the graft is successful, the two parts grow as a single plant, combining the strengths of both. Grafting is commonly used for fruit trees, ornamental plants, and flowering shrubs.
Why is grafting important?
Grafting is important because it allows gardeners to improve plant growth, combine good traits from different plants, and make plants more resistant to diseases. It can also help adapt plants to challenging soil or weather conditions. For example, grafting can enable a tree that produces high-quality fruit to grow on a rootstock that is well-suited to the local environment, leading to healthier and more productive plants.
What are the benefits of grafting?
Grafting provides many benefits, such as improving disease resistance, increasing the quality of fruit or flowers, and helping plants adapt to difficult growing conditions. It also allows gardeners to create multi-grafted trees that can produce several types of fruit, saving space in smaller gardens. Additionally, grafting can help preserve rare or heirloom plant varieties by propagating them in a controlled way.
What is a scion?
A scion is a piece of a plant that contains the desired traits, such as a specific variety of fruit, flower, or growth habit. The scion is the part of the plant that will grow above the graft union and produce leaves, flowers, or fruit. When choosing a scion, it is important to select healthy wood with at least two or three buds to ensure successful growth after grafting.
What is a rootstock?
A rootstock is the part of the plant that provides the root system for the graft. It determines the overall growth characteristics of the grafted plant, such as size, vigor, and adaptability to soil conditions. Rootstocks are chosen based on their disease resistance, tolerance to environmental conditions, and compatibility with the scion. The combination of a suitable rootstock and scion can lead to a stronger, healthier plant.
What tools are needed for grafting?
Common tools for grafting include a sharp grafting knife, which is used to make clean cuts on the scion and rootstock; grafting tape or rubber bands, which hold the graft in place while it heals; grafting wax, which seals the graft to prevent moisture loss and protect it from pests; and pruners, which are used to trim the scion and rootstock. It is also important to have a sterilizing solution, such as rubbing alcohol, to keep your tools clean and prevent the spread of diseases.
When is the best time to graft in New Zealand?
The best time to graft most fruit trees in New Zealand is in late winter to early spring, when the plants are dormant but beginning to swell with buds. During this time, the plant’s energy is focused on new growth, which helps the graft heal quickly. Bud grafting is typically done in late summer when the bark is “slipping” and can easily separate from the wood, making it easier to insert the bud.
What is whip and tongue grafting?
Whip and tongue grafting is a method where a slanted cut is made on both the scion and rootstock, allowing them to fit together tightly. A second cut, called a “tongue,” is made on each piece to create a more secure fit and increase the contact area between the cambium layers. This method is commonly used for young fruit trees and provides a strong union that heals quickly, making it ideal for beginners.
What is cleft grafting used for?
Cleft grafting is used to join a scion to a larger rootstock branch, often to rejuvenate old trees or grow multiple varieties on one tree. It involves making a cleft, or split, in the rootstock and inserting one or more scions into the cut. This method is useful for changing the variety of an existing tree or adding new branches to an older tree. It is often used for apples, pears, and other fruit trees to create multi-grafted trees.
What is bud grafting?
Bud grafting involves grafting a single bud onto the rootstock. In T-budding, a “T” shaped cut is made in the rootstock, and a bud from the desired plant is inserted. Bud grafting is often used for roses, fruit trees, and other ornamental plants. It is a very efficient way to graft because it uses less plant material and allows for multiple grafts on the same rootstock. This method is typically done in late summer when the bark is easy to peel.
What is bridge grafting?
Bridge grafting is used to repair trees that have been damaged, such as when bark has been stripped away by animals or accidents. The scions are grafted above and below the damaged area to “bridge” it, allowing nutrients and water to flow past the damaged section. This technique is especially useful for saving valuable trees that might otherwise die from the damage. It is important to use several scions to ensure a strong and effective bridge.
What is approach grafting?
Approach grafting is when both the scion and rootstock remain attached to their original plants during the grafting process. This method is often used for plants that are difficult to graft using other methods or for plants that need extra support during the healing process. Since both parts are still attached to their root systems, they continue to receive nutrients until the graft is successful. Once the graft has healed, the scion is cut from its original plant.
How do I choose the right rootstock?
To choose the right rootstock, consider the plant’s growth needs, disease resistance, and adaptability to your garden’s conditions. For example, if you have heavy clay soil, you may want to choose a rootstock that is tolerant of those conditions. If you need a smaller tree, a dwarfing rootstock is a good choice. The rootstock should be compatible with the scion to ensure a successful graft and healthy plant.
Can all plants be grafted?
Not all plants are compatible for grafting. Generally, plants must be closely related botanically for a successful graft. For example, apple scions can be grafted onto certain types of apple or pear rootstocks, but not onto unrelated plants like citrus. It is important to research which plants are compatible before attempting to graft, as incompatible grafts will not heal properly or may not grow at all.
Why is cambium contact important in grafting?
The cambium layers (the green part under the bark) of both the scion and rootstock must align for nutrients and water to flow between them, which is crucial for the graft to heal. The cambium is the layer of actively growing cells, and proper contact between these layers allows the scion and rootstock to bond and grow together. If the cambium layers are not aligned, the graft will fail.
How do I protect a new graft from drying out?
To protect a new graft from drying out, use grafting wax to seal the exposed areas and keep moisture in. Grafting tape can also be used to hold the graft tightly together and prevent moisture loss. It is important to keep the grafted plant in a sheltered area, away from direct sunlight and strong winds, until the graft has had time to heal.
What should I do if a graft fails?
If a graft fails, examine what went wrong, such as poor cambium alignment, drying out, or incompatibility between the scion and rootstock. Learn from the experience and try again with improved technique. Make sure your tools are clean, your cuts are precise, and the cambium layers are aligned properly. Sometimes grafting takes multiple attempts to get right, so don’t be discouraged if your first graft doesn’t succeed.
How long does it take for a graft to heal?
It can take several weeks for a graft to heal, depending on the type of plant and grafting method used. Whip and tongue grafts usually heal faster, while cleft grafts may take longer. During the healing process, it is important to keep the grafted plant well-watered and protected from extreme conditions. You will know the graft is successful when you see new growth from the scion.
What are multi-grafted trees?
Multi-grafted trees are trees that have multiple varieties of fruit grafted onto one rootstock, allowing them to produce different fruits on the same tree. This is a great way to save space in a garden, as you can enjoy a variety of fruits without needing multiple trees. Multi-grafted trees are popular in home gardens where space is limited, and they can also extend the harvest season by providing fruits that ripen at different times.
Can grafting help with disease resistance?
Yes, using a disease-resistant rootstock can help protect the grafted plant from certain diseases. For example, rootstocks that are resistant to soil-borne diseases can be used to graft susceptible scions, providing a healthier plant overall. This is especially useful in areas where certain diseases are common, as it reduces the need for chemical treatments and helps the plant thrive.
Do I need to sterilize my tools before grafting?
Yes, sterilizing your tools before grafting is very important to prevent the spread of diseases between plants. Use a sterilizing solution, such as rubbing alcohol, to clean your grafting knife, pruners, and other tools before making any cuts. This helps ensure that your grafts have the best chance of healing successfully and reduces the risk of infection.
What is the role of grafting tape?
Grafting tape holds the scion and rootstock together until the graft heals. It helps keep the cambium layers in contact and prevents the graft from moving, which is important for proper healing. Grafting tape also helps to keep moisture in and protect the graft from pests and diseases. Once the graft has healed and new growth has begun, the tape can be removed.
How do I care for a grafted plant?
To care for a grafted plant, keep it in a sheltered area away from strong winds and direct sunlight. Water the plant carefully, making sure it gets enough moisture without overwatering, which can cause the graft to rot. Protect the graft from pests, such as insects or birds, that may damage it. Regularly check the graft to make sure it is healing well, and make any necessary adjustments to keep the plant healthy.
Can grafting be used for ornamental plants?
Yes, grafting is often used to propagate ornamental plants, such as roses, flowering shrubs, and trees. Grafting allows gardeners to create new and interesting varieties with specific colors, flower forms, or growth habits. It is also used to produce standard forms of certain plants, such as weeping trees, by grafting a desirable ornamental variety onto a suitable rootstock.
Where can I learn more about grafting?
For more gardening tips and guides, visit MyGarden.co.nz to continue your grafting journey. There, you can find detailed instructions, helpful videos, and expert advice on various grafting techniques and other gardening topics. Whether you’re a beginner or an experienced gardener, MyGarden.co.nz has resources to help you improve your grafting skills and grow a healthy, productive garden.

References

Hartmann, H. T., Kester, D. E., Davies, F. T., & Geneve, R. L. (2010). Plant Propagation: Principles and Practices. Pearson Education.
Garner, R. J. (2013). The Grafter’s Handbook. Mitchell Beazley.
New Zealand Institute of Horticulture. (n.d.). Grafting Techniques. Retrieved from https://www.nzih.org.nz/
Royal Horticultural Society. (n.d.). Grafting and Budding Techniques. Retrieved from https://www.rhs.org.uk/
MyGarden.co.nz. (n.d.). Grafting Guides and Tips. Retrieved from https://mygarden.co.nz/
McKenzie, A. (2019). Successful Grafting for New Zealand Gardeners. Garden World Publishing.
University of California Agriculture and Natural Resources. (n.d.). Grafting and Budding Nursery Crop Plants. Retrieved from https://ucanr.edu/

Techniques for Successful Plant Grafting in New Zealand