Blog from Dana Lee, Pacific Horticulture College Student
I was very excited to learn that I was selected to write my blog posting on Fruit Culture with Gordan Mackay. I have a strong passion for food growing and look forward to the day I can have my own food forest or small-scale farm. Therefore learning about grafting and getting to visit Fruit Trees and More were definite highlights that I was looking forward to.
Gordon teaches with a passion for horticulture that is inspiring; he has taught us a variety of classes so far this year including pruning of mature fruit trees, training of 1 and 2 year-old fruiting trees and apiculture. We were lucky to have him today to teach us about the different types of grafting and training methods that are utilized in the horticultural industry.
Grafting in a nut-shell, is the joining of two living plant parts to create one plant. There are many reasons for grafting including when the plant variety does not grow true-to-seed, cuttings are difficult to root, to control tree size, for earlier fruiting, disease/pest resistance and/or adaptation to difficult soils or climates to name a few. To begin grafting you will require a rootstock (generally 2-years old) and a scion (generally 1-year old growth of the plant you wish to grow). The rootstock and scion need to be compatible for the vascular systems to combine and be successful. The rootstock will determine the mature size of the plant and they come in 5 categories: Midget (4-8’), Dwarf (8-12’), Semi-dwarf (12-20’), Semi-Standard (20-25’) and Standard (25-35’ – most hardy and vigorous). Some of the smaller rootstocks will require support for the lifespan of the plant or for at least the first 5 years. Selection of the rootstock will be dependent on the purpose of cultivation.
There are several grafting methods including t-budding, chip budding, whip graft, whip and tongue graft, wedge graft, saddle graft, cleft graft and side graft. We learned that certain grafting methods work better for certain plants. Roses are primarily grafted using the t-budding method, most fruit and ornamental trees are being grafted using chip budding or whip and tongue grafting, saddle grafting is used for rhododendrons and side/bench grafting are primarily used for conifers. Grafting is a form of surgery. Working with living tissues means working quickly and precisely to minimize the damage and stress to the plants as well as preventing infection. This means starting with good healthy plant parts, clean tools and maintaining hygienic surroundings.
In order to obtain a successful graft it requires compatibility between rootstock and scion; plants are to be of the same genera. Cambial contact must be made between the two plants that is air-tight. A solid connection between the two is important as this is an area containing undifferentiated cells that are actively dividing and will create a bridge of solid vascular tissue between the two pieces fusing them together. To ensure that this process can take place three additional factors need to be considered: warm temperatures, healthy plant tissues and the right type of cuttings taken at the right time of year.
Once the graft has taken hold and new growth well started (approximately 1 month) if the wrapping material does not decay naturally, remove grafting wrap or split it vertically with a sharp knife or razor blade and let the sun pull the material away from the scion. As the growth continues, remove all sprouts or other growth that originate below the graft as these are from the rootstock and will not be the plant you are attempting to grow. If there is no new growth the graft may have failed and this could be due to a variety of reasons including: incompatibility between rootstock and scion, cambiums not joining, scions placed upside down, grafting attempted in the wrong season, plant materials not healthy, or the scions were not dormant, dried out or injured by cold. There could also be other outside factors that affect the graft union such as scion being dislodged by a storm, birds or other means, graft was shaded too much or attacked by insects or disease or if the grafting tape was not cut/released in time the union can become girdled.
After a morning full of grafting we had the privilege of visiting Fruit Trees and More in the afternoon, owned and operated by Bob and Verna Duncan. The property covers 3/4 acre where Bob and Verna have been cultivating a large variety of fruiting plants for over 35 years. With typical BC fruits, peaches, cherries, nectarines, plums, apricots, apples and grapes Bob also grows exotics such as kiwis, lemons, limes, oranges, olives, pawpaws, pomegranates, and 150 varieties of figs. Bob believes that it’s worth trying to grow any plants that can grow within a modified Mediterranean climate and it truly shows in the vast orchard. We got to see first had some of Bob’s grafting handiwork on a fig tree. The original tree did not have as tasty figs as Bob would have liked so he decided to change the variety and bud grafted a different variety onto the strong root stock. The diverse fruit orchard provides a year-round bounty and is truly something to aspire to.