Special Topics in Horticulture: Fruit Tree Culture

Student Blog Post by Cecilia Cun

As a student at PHC we get to attend many amazing special topics and one of the topics was fruit tree culture by guest instructor Noah Alexander! Everyone at one point has wanted a fruit tree or planted one and wondered why aren’t I getting fruit or the fruits are not up to expectations. Well I am here to share some of the knowledge learnt by our amazing special topics teacher Noah Alexander to hopefully help you grow a happy and fruitful tree. 

Identification

First and foremost if you want to be successful you need to know what you’re going to grow or what you’re already growing because like people, each type of plant has a personal preference (soil type, amount of water and sunlight) and they will also react differently to being pruned as well. Generally speaking just knowing the genus of the plant will give enough information on how the plant wants to be treated and where it wants to be planted. 

The Right Plant For The Right Place

Another key factor for success is choosing the right plant for the right place, this can be applied to not only fruit trees but all plants in general. A fruit tree that is supposed to grow to be 20 feet tall won’t be happy in a small space and some trees like acidic soil while others like alkaline. If the tree isn’t happy not only will it not produce good fruit if at all any. When it isn’t happy it ain’t healthy either making them perfect victims for pest and disease to attack. So some things to consider before getting a fruit tree, are you in the right zone? Do you have the right soil type? How’s the drainage in the area? Is there enough sun or shade? Is the area big enough? 

 Pruning

We can’t talk about fruit trees without talking about pruning. Pruning a fruit tree has many benefits if done right. It can help you maintain fruiting on the tree, to keep fruit within reach (Size), create a strong structure for the tree (Shape), and for the health of the tree. Pruning should usually be done in the spring or summer. One thing that should be kept in mind when pruning is to not over prune and prune less than 25% of the overall live tree branches, we call this the pruning budget. Dead, damaged and diseased branches should not be part of your pruning budget. Fruit trees are prolific growers and if pruned too much they send out a lot of new growth which will mess with the shape and structure of the tree. It takes time to maintain a fruit tree and years to correct a mistake. 

IPM

Most plants are easily replaced but not so much with trees, that’s why preventative health care is key for trees. Fruit trees are very resilient and have a prolific growth habit. Many varieties of trees are available and each is susceptible to different pests and diseases. You should have a balance of bad insects and good insects because good insects usually prey on the bad and if you get rid of most of the bad the good won’t have food and not come back. With that being said you need to be 100% sure of what it is you are looking at before taking action because many insects can look similar and you don’t want to go on an insect killing spree for it to turn out that those were beneficial insects. 

Monitor pests till they reach a certain threshold before you take action. Another preventative measure is to keep the disease triangle in mind. For a plant to be susceptible to disease there needs to be a pathogen present, a susceptible host plant and ideal environmental conditions. If any one of these are missing, disease should not occur. The best way to keep this triangle incomplete is to keep your plant healthy by caring for it properly and putting your plant in the right place. 

Here are a list of some of the commonly found problems:

Aphids

Can be a problem, but lady bugs are a big predator for them. If aphids are only on one branch, really just leave it for the lady bugs to eat. There are many different types of aphids out there that target specific plants.

Winter moths

Are the little green worms/caterpillars.

Happens early in the spring. They come out as the buds for flowers start to swell and bloom. Winter moths will girdle the flowers and prevent pollination. You notice that blooms will drop off early.  They can swing over 200m in their thread. They live in a six year cycle. They don’t have a beneficial insect that goes after them. Put a sticky back on from October to February to catch them before they crawl up your tree. This will help reduce the number of this pest.

Tent caterpillars

Like the name implies they create a threaded tenant like structure on tree branches in early summer. Caterpillars are yellow and black. Little eggs of parasitic wasps get attached to the back of the caterpillar that will eventually kill them. So check before killing the caterpillar. We want more of these wasps.

Spider Mites

Can be a major problem. It takes a couple of years before it kills the tree. There is usually a reason why plants become hosts to these pests. Unhealthy plants are the no.1 target for these pests.

Scale

Lots of citrus have it. Common on citrus. Can be hard to see sometimes because they look like a little bump. They secrete sooty mold, this is a sign to look under leaves for them.

Wooly allergen

When apple trees are unhealthy or old this becomes present. It’s a sure sign that other stresses are present. Rub them off.

Cherry bark tortrix

Insect burrows into the bark. You will see cherry trees try to protect themselves by secreting sap out. 

Powdery mildew

White or grey dust like fungus on the surface of the leaves or buds. 

Apple scab

Can be on crab apples/ all varieties of apples. Also damages the leaves.

Fire Blight

Looks like the tips of leaves are burned back. 

Pear trellis rust

Red spots on leaves. Common on pear trees. Means that a juniper is nearby. Junipers are the host plant for this disease to over winter in. More of an aesthetic problem.

Brown rot

Mummify flowers and if fruit is produced, fruits are mummified.

Grafting

Who doesn’t want to make a frankenstein tree with different fruit on it! We only had a very light introduction to this subject due to time constraints and because it’s such a huge subject to talk about. Here are the takeaways for grafting. Seeds don’t usually produce the same fruit as the mother plant so people will graft a piece of the tree onto a strong/desirable root stock. Usually grafted onto a wild rootstock. Orchids have a mother tree they take pieces off of to graft. Research the compatibility charts to discover which varieties are compatible for grafting.  Generally stay in the same genus for best success. Do it in the early spring as growth begins, but you can take bud clips in early summer. Make sure there’s no disease. Use sharp clean tools. Cambium from the scion bud chip needs to line up. Make sure they’re not too big or too small. You need to protect them after grafting them. Best to take and do as many grafts as possible because not all of them are gonna work. Check on the graft frequently and keep it moist but not wet. There is a lot more information on this.

Fruit trees can be a lot of work but well worth it. There’s definitely something sweeter about eating your own home grown fruit than grabbing one from the grocery store. It will be a learning process to reach success but keep your chin up because life is all about experiencing both the good and the bad. There is a lot more information out there, one place the instructor recommended was to take a look at is the BC fruit growers association (www.bcfga.com) and of course the HCP has many programs and knowledgeable people who would love to share some of their insights. I hope you found this post helpful in some way and happy growing!

Image: https://www.worldatlas.com/articles/where-do-apples-come-from-originally.html