Introduction

Grafting, the process of joining different plant parts to form a single plant, has been practiced for centuries. One of its most common applications is grafting trees onto specific rootstock. This technique is essential in horticulture and commercial agriculture for several reasons, offering numerous benefits to growers. In this article, we will explore why trees are grafted to specific rootstock, the historical origins of this practice, and its modern applications in commercial agriculture.

Benefits of Grafting Trees to Specific Rootstock

1. Size Control: One of the primary reasons for grafting trees onto specific rootstock is size control. Different rootstock varieties have varying growth characteristics, such as dwarfing, semi-dwarfing, or vigorous growth. Growers can select rootstock that matches their desired tree size, making it easier to manage orchards and gardens. Dwarfing rootstock, for example, is used to create smaller, more manageable trees suitable for small spaces or easier fruit harvesting.

2. Disease Resistance: Certain rootstock varieties exhibit resistance to specific diseases and pests. By grafting trees onto disease-resistant rootstock, growers can protect their plants from common threats. This practice is especially crucial in commercial agriculture, where disease management is essential to maintain high yields and product quality.

3. Adaptation to Soil and Climate: Different rootstock varieties are better suited to specific soil types and climatic conditions. Grafting onto the appropriate rootstock ensures that trees can thrive in their environment. For instance, some rootstock varieties are tolerant of wet or drought-prone soils, allowing trees to flourish in challenging conditions.

4. Improved Fruit Quality and Production: Grafting onto suitable rootstock can enhance fruit quality and production. Rootstock can influence factors like fruit size, flavor, and yield. Growers can select rootstock that complements the desired fruit characteristics, leading to better marketable produce.

Historical Origins of Grafting to Rootstock

The practice of grafting trees onto specific rootstock has ancient origins, dating back to civilizations such as the Mesopotamians and the Romans. These early horticulturists observed the benefits of grafting and began to experiment with different rootstock varieties. Over time, grafting techniques evolved and were passed down through generations.

One of the most well-known historical figures associated with grafting is Antonie van Leeuwenhoek, a Dutch scientist who made significant contributions to microscopy in the 17th century. He conducted extensive experiments on grafting, helping to advance our understanding of the process and its applications in agriculture.

Modern Applications in Commercial Agriculture:

In modern commercial agriculture, grafting trees to specific rootstock is a common and essential practice. Commercial growers employ various grafting techniques, including whip-and-tongue, cleft, and bud grafting, to create grafted trees tailored to their specific needs. Here are some ways in which this technique is used today:

1. Fruit Orchards: Commercial fruit growers use grafting to produce high-yielding and disease-resistant fruit trees. For instance, apple orchards may use dwarfing rootstock to create compact trees that are easier to manage and harvest. Disease-resistant rootstock is also crucial in reducing the need for chemical treatments.

2. Vineyards: In viticulture, grapevines are often grafted onto specific rootstock to control growth and disease resistance. Rootstock selection can impact grape quality and wine characteristics. Grafted vines are also used to combat the threat of phylloxera, an insect pest that can devastate vineyards.

3. Nurseries: Nursery operations play a vital role in supplying grafted trees to commercial growers and home gardeners. These nurseries maintain a wide range of rootstock varieties, scion wood, and grafting expertise to meet the diverse needs of customers.

4. Urban Landscaping: Grafted trees are also commonly used in urban landscaping. Dwarfing rootstock can be employed to create aesthetically pleasing, manageable trees that fit well within urban environments. These trees require less space and maintenance while providing shade and beauty.

Grafting trees to specific rootstock is a time-honored horticultural practice with numerous benefits for commercial growers. It allows for size control, disease resistance, adaptation to varying conditions, and improved fruit quality and production. The historical origins of grafting date back to ancient civilizations, and today, it remains a fundamental technique in modern agriculture. Commercial growers rely on grafting to optimize their crop yields, manage orchards, and ensure the health and productivity of their trees.

Selecting the Rootstock

Selecting the right rootstock for tree grafting is a critical step in the process, as it can significantly influence the growth, health, and productivity of the resulting tree. The choice of rootstock depends on various factors, each of which plays a crucial role in the success of the grafting project. Here, we will delve deeper into the considerations when selecting rootstock for tree grafting:

Soil and Climate Conditions:

Soil type and climate conditions have a substantial impact on tree growth. Different rootstock varieties exhibit varying levels of tolerance to soil types, pH levels, and climatic factors. When selecting rootstock, consider the specific conditions of your location. For example:

1. If you have well-draining sandy soil, you may opt for a rootstock that performs well in such conditions.
2. In areas with heavy clay soil, selecting a rootstock with good adaptability to clay can enhance the tree's chances of thriving.
3. Cold-hardy rootstock is essential for regions with harsh winters, while heat-tolerant rootstock is preferable in hot climates.

Disease Resistance:

Rootstock can provide natural resistance to certain diseases and pests. This can significantly reduce the need for chemical treatments and increase tree longevity. When grafting trees, especially in commercial orchards, it's crucial to assess the prevalent diseases and pests in your area and select rootstock varieties with corresponding resistance. For example, apple growers in regions prone to fire blight may choose rootstock with inherent resistance to this bacterial disease.

Tree Size and Vigor:

Rootstock has a significant impact on tree size and vigor. The choice of rootstock can determine whether the tree will be dwarf, semi-dwarf, or vigorous in its growth.

• Dwarfing rootstock is preferred in small spaces or for ease of harvest, as it produces compact trees with lower canopy height.
• Semi-dwarfing rootstock offers a balance between tree size and productivity and is commonly used in commercial orchards.
• Vigorous rootstock is selected when a larger tree size is desired, which may be suitable for shade or ornamental purposes.

Tree Species Compatibility:

Different tree species require specific rootstock varieties for successful grafting. Each rootstock has unique characteristics that make it compatible with certain tree species. For instance:

• Apple trees often use rootstock varieties like M-111 or MM.106, which are well-suited for apple grafting.
• Peach and nectarine trees may be grafted onto rootstock varieties like Lovell or Guardian.

Long-Term Goals:

 

Consider your long-term goals when selecting rootstock. If you're planning a home orchard or garden, your priorities may differ from those of a commercial grower. Factor in aspects such as tree lifespan, maintenance requirements, and space limitations. Some rootstock varieties may lead to earlier fruit production, while others may delay fruiting to encourage better root development.

Local Expertise and Recommendations:

• Seek advice from local agricultural extension services, horticulturists, or experienced growers in your area. They can provide valuable insights into which rootstock varieties have been successful in your region.
• Joining local gardening or orcharding clubs can also provide a network of knowledgeable individuals who can offer guidance on rootstock selection.

The process of selecting the right rootstock for tree grafting is multifaceted and requires careful consideration of soil and climate conditions, disease resistance, tree size, species compatibility, nursery stock quality, long-term goals, and local expertise. Making an informed decision at this stage sets the foundation for a successful grafting project, leading to healthy and productive trees in the future.

Common Types of Rootstock

Citation:

1. Dwarfing Rootstock: Citation is a dwarfing rootstock, which means it has the inherent ability to limit the size of the grafted tree. This characteristic is particularly valuable in smaller gardens or orchards where space is limited. It allows for the cultivation of fruit trees that can be maintained at a manageable height, making it easier to harvest the fruit without the need for ladders or specialized equipment.

2. Tolerant to Wet Soils: Citation rootstock exhibits a degree of tolerance to wet or poorly-drained soils. This trait is advantageous in regions with excessive moisture or areas prone to occasional waterlogging. It ensures that the grafted tree remains healthy even in less-than-ideal soil conditions.

3. Suitable for Stone Fruit Trees: Citation is an excellent choice for stone fruit trees such as peaches, nectarines, and plums. It provides a sturdy foundation for these fruit varieties, ensuring good stability and growth.

4. Reduces Tree Size: One of the key attributes of Citation rootstock is its ability to reduce the overall size of the grafted tree. This reduction in tree size simplifies maintenance tasks, such as pruning and thinning, and makes fruit harvesting more accessible.

Krymsk86:

1. Semi-Dwarfing Rootstock: Krymsk86 is considered a semi-dwarfing rootstock. It strikes a balance between dwarfing and vigorous rootstocks, resulting in trees of moderate size. This characteristic allows for better adaptability to various orchard sizes and growing conditions.

2. Well-Adapted to Various Soil Types: Krymsk86 is known for its versatility in adapting to different soil types. Whether you have sandy, loamy, or clayey soil, this rootstock variety can thrive and provide a stable foundation for the grafted tree.

3. Resistant to Nematodes and Diseases: Krymsk86 rootstock exhibits resistance to nematodes, which are microscopic parasites that can damage plant roots. Additionally, it shows resistance to certain diseases, enhancing the overall health and longevity of the tree.

4. Compatible with a Wide Range of Stone Fruit Trees: Krymsk86 is a versatile choice for stone fruit trees, including peaches, nectarines, plums, and apricots. Its adaptability and disease resistance make it a popular option for commercial growers seeking reliable rootstock.

Lovell:

1. Semi-Dwarfing Rootstock: Lovell, similar to Citation, is a semi-dwarfing rootstock. It offers a balance between tree size control and healthy growth.

2. Thrives in Well-Drained Soils: Lovell rootstock performs best in well-drained soils, making it an excellent choice for orchards or gardens with proper soil drainage. Adequate drainage helps prevent root diseases and ensures the tree's overall vigor.

3. Excellent for Peaches, Nectarines, and Apricots: Lovell is particularly well-suited for stone fruit trees such as peaches, nectarines, and apricots. It provides a strong and reliable foundation for these fruit varieties, resulting in healthy growth and fruit production.

4. Promotes Vigorous Growth and Early Fruiting: One of the notable characteristics of Lovell rootstock is its ability to promote vigorous growth and early fruiting. This trait is advantageous for growers looking for quicker yields from their trees.

Maxma:

1. Semi-Vigorous Rootstock: Maxma is categorized as a semi-vigorous rootstock, meaning it imparts moderate growth to the grafted tree. This characteristic makes it suitable for larger tree sizes and orchards.

2. Tolerant to Drought and Salinity: Maxma rootstock exhibits tolerance to drought conditions and salinity in the soil. This resilience allows trees grafted onto Maxma to thrive in regions with challenging water availability and soil salinity levels.

3. Suitable for Apple and Pear Trees: Maxma rootstock is commonly used for apple and pear trees. It provides the necessary support and anchorage for these fruit varieties, ensuring stability and healthy growth.

4. Provides Good Anchorage and Disease Resistance: Maxma rootstock offers a robust root system that provides stability and anchorage to the tree. Additionally, it possesses resistance to certain diseases, contributing to the overall health and longevity of the grafted tree.

M-111:

1. Vigorous Rootstock: M-111 is classified as a vigorous rootstock, imparting significant growth to the grafted tree. This characteristic is well-suited for growers looking to cultivate larger trees.

2. Ideal for Apple Trees: M-111 rootstock is particularly ideal for grafting apple trees. Its vigorous growth and robust root system provide the necessary support for apple varieties.

3. Resistant to Fire Blight and Collar Rot: M-111 rootstock exhibits resistance to specific diseases, notably fire blight and collar rot. This disease resistance contributes to the tree's overall health and reduces the need for disease management.

4. Promotes Large Tree Size and Robust Root Development: One of the primary advantages of M-111 rootstock is its ability to promote large tree size and robust root development. This results in strong and healthy trees that can withstand various environmental challenges.

Selecting the right rootstock for tree grafting involves considering a range of factors, including growth characteristics, soil and climate adaptability, disease resistance, and compatibility with specific tree species. Each rootstock variety, such as Citation, Krymsk86, Lovell, Maxma, and M-111, offers unique attributes that cater to the specific needs and goals of growers in various agricultural contexts. Making an informed choice regarding rootstock is crucial to achieving successful tree grafting outcomes.

Process of Grafting a Tree

Gather Your Tools and Materials:

Before you start grafting, gather all the necessary tools and materials to ensure a smooth process. You'll need the following:

1. Rootstock trees of your chosen variety.
2. Scion wood - healthy branches from the desired fruit tree variety.
3. Grafting knife or sharp pruning shears.
4. Grafting tape or rubber bands.
5. Wax or grafting compound to seal the graft.

Preparing the Rootstock:

1. Choose a young rootstock tree that's about the same diameter as the scion wood you'll be grafting. Ideally, the rootstock should be one to two years old.

2. Make a clean, diagonal cut about 6-8 inches above the soil level. This will be the grafting site.

3. Optionally, you can make a second cut above the first one, creating a "T" shape. This is particularly useful for whip-and-tongue or cleft grafts.

Preparing the Scion Wood:

1. Select healthy scion wood from the desired fruit tree variety. The scion should be about 6-8 inches long and have several buds.

2. Using a sharp grafting knife or pruning shears, make a clean, angled cut at the base of the scion. Ensure that the cut matches the grafting style you plan to use on the rootstock.

3. If you're using a whip-and-tongue or cleft graft, make a matching cut on the scion's base to create a tongue or a wedge.

Grafting Techniques:

There are several grafting techniques, but we will focus on two common methods: whip-and-tongue graft and cleft graft.

1. Whip-and-Tongue Graft:

   a. Make a matching tongue or wedge on both the scion and rootstock by making a small slit in the center of the cut.

   b. Insert the tongue of the scion into the rootstock's tongue or wedge, ensuring a tight fit.

   c. Secure the graft by wrapping it with grafting tape or rubber bands. Make sure the connection is snug but not too tight, allowing for proper healing.

2. Cleft Graft:

   a. Split the top of the rootstock vertically, creating a cleft or opening.

   b. Insert the prepared scion into the cleft, ensuring that the cambium layers of the scion and rootstock align.

   c. Secure the graft by wrapping it with grafting tape or rubber bands.

Sealing the Graft:

To prevent the graft from drying out and to keep pathogens out, it's essential to seal the graft union with wax or grafting compound. This helps create a protective barrier and promotes successful healing.

1. Apply a generous layer of wax or grafting compound over the entire graft union, ensuring no gaps are left exposed.

2. Be sure to cover the graft thoroughly, including any exposed cut surfaces on the rootstock.

Post-Graft Care:

After successfully grafting the scion onto the rootstock, follow these essential post-graft care steps to ensure the health and growth of your newly grafted tree:

1. Maintain a clean and well-ventilated environment for the grafted tree.

2. Monitor the graft union regularly for signs of healing and growth. You should see new shoots emerging from the scion within a few weeks to months, depending on the tree species and grafting technique used.

3. Water the grafted tree appropriately, ensuring it receives adequate moisture without becoming waterlogged.

4. Protect the graft from extreme weather conditions, pests, and diseases.

5. Prune away any unwanted growth below the graft union to direct energy to the scion.

In Summary

Tree grafting from rootstock is a fascinating horticultural practice that allows you to create new trees with desired characteristics. The selection of the right rootstock is crucial, as it determines the tree's ultimate size, disease resistance, and adaptability. By following the step-by-step process outlined in this guide and understanding the distinguishing characteristics of rootstock varieties like Citation, Krymsk86, Lovell, Maxma, and M-111, you can successfully graft and grow healthy fruit trees or ornamental plants in your garden or orchard. Remember that practice and patience are key to mastering this skill, and each successful graft will bring you one step closer to becoming a proficient grafter.

For more information on grafitng, see our bare root trees for sale or explore our Fruit Tree Central blog collection.

You can find information on specific rootstock for our trees in our Fruit and Nut Tree Characteristics database.

Additional Resources

1. Grafting from University of Missouri Extension: This resource provides a detailed guide on the grafting process, including cutting the scion, fitting the stock and scion, wrapping and waxing the graft, and different grafting techniques such as cleft grafting. It emphasizes the importance of aligning the cambial areas of the scion and stock for successful graft union​.

2. Grafting 101: An Introduction to Grafting - UC Botanical Garden: This article introduces the concept of grafting, its applications in combining desirable traits of different plants, and basic grafting techniques. It outlines the process of selecting rootstock and scion, and the steps involved in cutting, splicing, and sealing them together. The article also addresses the challenges in grafting and encourages practice and exploration of this horticultural practice​.

3. Growing Fruit: Grafting Fruit Trees in the Home Orchard from UNH Extension: This fact sheet focuses on cleft grafting in home orchards. It describes the process of preparing older trees for top-working using cleft grafting, which involves creating a split in the wood and inserting scions. The article provides step-by-step instructions and emphasizes the importance of proper alignment of cambial zones for successful grafting​.

4. Fruit Tree Propagation - Grafting and Budding from Penn State Extension: This comprehensive guide discusses various grafting and budding techniques, such as bench grafting, cleft graft, bark and inlay grafts, and chip budding. It also covers the necessary materials and tools for grafting, emphasizing the importance of a sharp knife. The article highlights the significance of grafting in propagating fruit trees and repairing damage​. cannot be done so by cuttings or seeds, and details the part of the vegetative wood, usually the stem or other aboveground plant part, from the desired variety to be propagated, known as the scion.