Understanding Grafting and Rootstock

What is Grafting?

Grafting is the physical process of joining two plants so that they grow as one. The top portion (scion) produces the fruit or flowers, while the bottom portion (rootstock) provides the root system. Once healed, the grafted plant functions as a single plant combining traits from both components.

Treatments may include fungicides, insecticides, biologicals, or coatings that improve handling and performance.

What is a Rootstock?

Rootstock is the lower portion of a grafted plant that forms the roots and crown. It is selected for beneficial underground or structural traits such as:

• Disease resistance
• Nematode resistance
• Improved nutrient uptake
• Environmental stress tolerance
• Plant vigor control

The rootstock does not determine fruit variety, only plant performance.

What Crops are Commonly Grafted?

Grafting is widely used in both vegetable and woody crops:

Vegetables

• Tomato
• Watermelon
• Cucumber
• Eggplant
• Pepper

Fruit & ornamentals

• Apple
• Citrus
• Grapes
• Roses
• Japanese maples

Vegetable grafting has grown rapidly in protected culture and high-value production systems.

Why do Growers Use Grafted Plants?

• Disease management – resistant rootstocks help manage Fusarium, Verticillium, bacterial wilts, and nematodes
• Improved vigor – stronger roots increase nutrient uptake and plant growth
• Higher yields – healthier plants often produce more for longer periods
• Stress tolerance – grafted plants handle drought, salinity, and temperature stress far better

When is grafting most beneficial?

Grafting is most useful when:

• Soil disease pressure is high
• Crop rotation is limited
• Growing in tunnels or greenhouses
• Producing high-value crops
• Using heirloom varieties with weak roots

For more information, please see links below:

• Propagation – NC State Extension Gardener Handbook
• Plant Propagation – University of New Hampshire Extension