Grafting fruit trees and ornamental plants can be a fantastic way to enhance your garden. In this blog post, we’ll cover the basics of grafting, different grafting techniques, and how to ensure successful grafting. Whether you’re a beginner or an experienced gardener, this article will provide you with the information you need to start grafting and making the most of your garden.
What is grafting?
Grafting is a technique used to combine desirable qualities of one plant, such as fruiting or flowering, with the strong and resilient roots of another plant. Although grafting requires skill and practice, it can be a rewarding process.
Suitable plants for grafting:
Fruit trees are often grafted onto fruit rootstocks because growing them on their own roots can result in excessive vigour. Grafting also allows for faster production of fruiting plants.
Ornamental shrubs and trees are grafted when it’s challenging to propagate them through other methods like cuttings or when specific cultivars don’t come true from seeds. Grafting helps strengthen weak-growing plants and promotes the development of larger flowering plants. Common examples of grafted shrubs and trees include Acer palmatum, Hamamelis, Wisteria, Thuja, and Picea.
When to graft:
Ornamental plants are typically grafted in early spring before the sap rises, but it can also be done in autumn.
The timing for fruit tree grafting varies depending on the technique. Chip-budding and T-budding are performed from mid-summer to early autumn, while whip-and-tongue grafting occurs in late winter or early spring.
How to graft:
Most plants are grafted within their own species, although sometimes grafting within the same genus or family is possible. Here are some key points to keep in mind for successful grafting:
- Use healthy plant material.
- Have a sharp knife that is regularly sterilised.
- Make straight cuts so that the rootstock and scion fit together snugly.
- Ensure the cambiums (the green layer beneath the bark) of the rootstock and scion meet, preferably on both sides of the stem.
- Wrap the graft with grafting tape, polythene strips, or raffia.
- Apply grafting wax to any exposed cut surfaces.
Grafting ornamental trees and shrubs – spliced grafts:
Side-spliced grafting is typically done in late winter or early spring before bud break. Follow these steps:
- Cut the scion wood (healthy one to two-year-old wood) into 15-25cm lengths.
- Trim the rootstock to about 7.5cm and make a downward nick about 3cm below the top.
- Make a downward-sloping cut on the rootstock, starting from the top and meeting the first cut.
- Cut one side of the scion wood to match the length of the rootstock cut.
- Make a short angled cut at the base of the scion wood.
- Fit the scion wood into the rootstock, ensuring the cambiums meet.
- Wrap the graft and cover exposed cut surfaces.
If possible, place the grafted plant in a propagator or greenhouse. Avoid over-watering but mist regularly. Successful grafts should start showing new growth within six to eight weeks.
Grafting fruit trees – whip and tongue grafting:
This method is commonly used for fruit and some ornamental plants. Perform whip and tongue grafting in March or early April on rootstocks that were planted 12 months prior. Here’s what you need to do:
- Select healthy shoots from the scion tree in December or January.
- Bundle five or six scions and heel them into a well-drained, sheltered site, leaving 5-7.5cm above the soil or keep them in a plastic bag in the refrigerator until spring.
- Before bud break in February, cut the top of the rootstock about 15-30cm above ground level.
- Make specific cuts on both the rootstock and scion to interlock them securely.
- Match the cambiums as closely as possible and bind the graft firmly.
- Remove the binding after about eight weeks when a callus is visible.
The scion refers to the portion above the graft. It is a young shoot or bud from a plant that possesses desirable characteristics such as excellent flavour, colour, or disease resistance. All the top growth of a grafted plant, including leaves, flowers, and fruits, comes from the scion. By combining the rootstock and scion, you can ensure a hardy and productive plant.
Remember these special considerations:
When planting grafted plants, do not bury the graft joint underground. If the rootstock sprouts its own growth or the scion develops its own roots, the desired characteristics of the grafted plant may be lost. For instance, a Granny Smith apple tree could start producing unrecognizable red apples from rootstock shoots.
Some rootstocks may require winter protection, such as grafted roses. Cold-climate gardeners should cover the graft in late fall but uncover it in spring to prevent unwanted sprouting from the rootstock.
What if the graft point looks ugly?
Although gardeners try their best to make the graft point look neat, even experts can not control how the graft area will look. However, the look does not impact the health of the plants.