Ignoring your fruit trees in winter is the agricultural equivalent of wearing a t-shirt in the snow. It simply doesn’t make sense. So why is it that so many farmers are choosing to overlook many important winter preparations and practices?
Winter is in full force in the Okanagan and it may have come a little quicker than everyone had hoped for. Whether we enjoy winter or not, all sorts of winter preparations need to be done. For Canadians, this seems to be a natural, choreographed dance. Be it your garden, house, de-icing the trailer for the winter or shoveling your driveway, each household seems to be able to do these tasks without even thinking. Your fruit trees should be exactly the same and should be part of this yearly ritual.
Pruning your trees correctly is a crucial art and it needs to be done correctly and efficiently. A thorough understanding of how and why plants grow will aid in your pruning and regrowth success. Firstly, let’s look at the benefits of pruning.
Pruning correctly can help to:
- Maintain a desired size and shape
- Promote a certain type of growth
- Improve fruit quality by maintaining a balance between vegetative (wood) and the fruit growing
- Increase fruit size by removing the excessive flower buds
- Encourage the growth of new shoots, with high-quality flower buds
- Encourages light into the canopy, which is required for flower and bud development, fruit set and growth
- Keep the canopy of the tree open, allowing for a better spraying ability and pest control
- Increase air flow through the canopy; reducing drying and certain diseases
- Reduce yield and improve fruit size by increasing the ratio of leaf area to fruit
- Delay premature fruiting in young trees
Secondly, let’s look briefly at fruit trees. Both buds and hormones play an integral part in pruning success.
Buds
Buds are important to the growth of trees, mainly vegetative and reproductive. Fruit tree training, pruning and bud manipulation work simultaneously. Depending on the fruit tree, approximately seven leaves are usually found on each bud. Shoots start to emerge in the spring as a result of shoot elongation. Some of these shoots will further develop into flower buds, which are actually just modified shoots. Buds can, to some degree, be manipulated so that they become a flower bud as opposed to remaining vegetative. Growth promoting regulators can be applied, for example. To ensure your fruit trees continually produce high quality fruit, a balance of reproductive and vegetative growth should be maintained.
Plant Hormones
Hormones in a plant are usually created in small amounts in one part of a plant and moved to another part of the plant, where a reaction occurs. Various hormones control different aspects of growth in a plant. For this reason, plant hormones and their basic functions should be understood when pruning.
- Two hormone types exist in plants; “promoters,” and, “inhibitors.” It is generally recommended that you become familiar with the different types.
- “Promoters,” usually cause bud and stem growth, as well as cell division, whereas, “inhibitors,” usually slow down or stop shoot development and growth.
- It is the balance of these two types of hormones that promote healthy growth and development.
- Low levels of inhibitors result in vegetative growth.
- The levels of inhibitors in a plant decreases, as the plant is exposed to winter temperatures, which is when pruning would be most efficient.
- Plant hormones can be manipulated to promote growth and development.
Lastly, let’s look briefly at the different types of pruning cuts. When making any type of pruning cut, it is important to use techniques that encourage the cut surface to heal quickly; reducing disease and insect infection. Cuts should be made close to the neighboring branch, without leaving stubs.
- Thinning cut: this removes an entire branch back to a side shoot branch. This type of cut does not revitalize the tree near the cut, like some of the other types of pruning cuts.
- Heading cut: this removes the terminal portion of a branch, which increases growth of the lower-level buds.
- Bench cut: this removes upright branches back to a side branches that are similar in diameter to the branch being pruned, but are less outward growing. This opens the tree up in the center and spreads the branches outward.
Now that we are all experts on the basics of pruning, let us know if you’ve uncovered some helpful basics too. When in doubt, remember that we are here to help. Reach out to a Growers Supply Co. expert for more tailored advice and help.