Winter Wisdom for Fruit Trees
Notes prepared by Katie Finlay of Grow Great Fruit
Pruning: parts of a tree
At the beginning of any conversation about pruning, it’s useful to talk about terminology. In the Grow Great Fruit pruning world, this is how we identify the different parts of the tree.
In a typical ‘vase-shaped’ tree, the limbs (also called branches) are vertical, and the laterals (also called side branches or side shoots) are more horizontal.
Once the tree shape is established, limbs are usually not replaced or pruned. The laterals (side shoots) are small branches growing from limbs, and maintenance pruning is mainly aimed at renewing the laterals.
A couple of other points to note:
- The graft union must be kept clear of the ground. For trees on dwarfing rootstock, the higher you plant the graft union above the ground level, the greater the dwarfing effect.
- Learn to identify different types of buds. Generally speaking fruit buds are fat and furry, while leaf buds tend to be thin and flat. They will often be together but not always.
- And finally, suckers are shoots that grow from below the graft union.
How does a tree respond when you prune?
Our mantra is that there is no “right” or “wrong” when it comes to pruning, just cuts and consequences! Understanding how a tree is likely to respond when you prune it removes a lot of the fear of getting it wrong.
Pruning changes the balance between above and below-ground parts of the tree. After pruning, trees respond by growing more shoots until the balance re-established, with regrowth mainly stimulated near the cuts. The more pruning you do, the more regrowth you’ll get.
Trees are on a continuum between growing fruit and wood. No cutting = maximum fruit production, and hard pruning = maximum wood growth.
Overall, pruning reduces growth and is one of the best ways to control tree size.
Two basic pruning cuts: heading cuts
Heading cuts removes the end of shoots or limbs including the apical bud (the bud at the end). The job of the apical bud is to grow towards the sun, which it does by releasing a hormone that inhibits the lower buds from growing so the apical bud can hog all the tree’s energy.
Heading cuts remove this apical dominance, which has the result of stimulating growth of new shoots near the cut. It’s the most invigorating type of pruning cut.
The shoot or shoots which grow from the buds immediately below the cut re-establish apical dominance.
Heading cuts are disruptive to the natural growth and form of trees, but they’re very useful for inducing branching at specific points to create the desired shape of tree.
Thinning cuts
Thinning cuts are used to remove entire shoots or branches, and to shorten laterals back to a side shoot or spur. It’s a more calming cut than a heading cut because it doesn’t stimulate new branches to grow. It’s the most important cut in maintenance pruning, and helps to increase fruit production.
The 10 Key Pruning Principles
- Remove dead and diseased wood. Dead wood is brown, live wood is green. Remove as much diseased wood as possible without sacrificing too much healthy wood.
- Prune as little as possible to maintain correct shape (because hard pruning encourages wood growth while light pruning keeps the tree calm and fruitful.
- Winter pruning encourages growth.
- Summer pruning slows growth and reduces disease risk
- Heading cuts create branching
- Sap flows most strongly to the top of the tree.
- Horizontal wood produces more fruit than vertical wood.
- Encourage fruit to grow close to main limbs.
- Prune young trees when you plant them.
- Remove suckers once a year.
The Grow Great Fruit Foolproof 7-step Pruning Method.
This method can be used for all fruit trees. Pay particular attention to steps 4 and 5.
- Remove dead wood, and diseased wood without sacrificing too much healthy wood. It’s useful to remove obvious large dead or diseased branches before you start as it’s easier to see the shape of the tree. If there are no dead branches skip this step.
- Look at the tree and imagine what shape you want it to be, e.g. vase, espalier.
- Identify the permanent limbs. Can you identify any major limbs or branches that need to be removed, especially if they’re growing in the middle of the tree? If not sure, leave them for now. (A word of caution: Don’t remove all laterals at this stage just because they’re growing into the centre of the tree, you may need them for fruit production.)
- Choose the easiest looking limb. Starting at the top of the limb, define and cut the leader to the right height. This is where you get to reshape the tree every year. Choose a leader that is at the right height, and going in the right direction to create the shape of tree that you want.
- Work down the limb, making a decision on every lateral. There are only 3 choices: (a) leave alone, (b) shorten, (c) remove. Each time you come to a large lateral then STOP and take a step back. Decide whether it’s a limb, or a lateral. If you decide it’s a limb, follow the same process as above. If you decide it’s a lateral, either shorten or remove it.
- Do the next limb, and methodically work your way around the tree
- Remove suckers from below the graft union
A note on shortening laterals
The key thing to remember is that you don’t want bare real estate on your branches. The laterals are the fruit-bearing parts of the tree, so the goal is to have laterals growing at regular intervals along the whole length of each limb.
Therefore, don’t follow “rules” like removing all the laterals that grow into the middle of the tree.
Establishment pruning
When you plant the tree in winter, prune all limbs to an outward-facing bud at knee height. If the tree is a “whip” or “rod” (no branching), cut it off at knee height. Make sure there are at least 3 or 4 healthy buds below the cut.
If the tree being planted already has enough limbs, head them all back to the same height, leaving the weaker limbs slightly longer than strong limbs.
Finally, remove any suckers , i.e. shoots growing from below the graft.
Over the following spring and summer the buds below the pruning cut will grow into new shoots (which will become permanent branches in the tree). The top buds will usually experience the strongest growth.
The following winter, count the number of limbs in your tree. The ideal number for a vase shaped tree is between 8 and 12 limbs. If there are less than 8, prune the tree hard again to create more branching.
If there are enough limbs, choose the best ones to keep, and remove any that are in the wrong place, e.g. growing into the centre of the tree or crossing over other limbs.
Winter tips: Hygiene
- Pick up and dispose of fallen fruit under trees, and any fruit left behind in the tree after you’ve picked—even if it’s shrivelled up. It provides habitat for many pests to survive over winter, and is a potential source of disease next spring.
- Make sure diseased leaves under your trees have gone by spring.
Mowing and spraying leaves with worm tea can help them break down. Or collect, compost, and return to the soil. - Use chickens or other poultry to seek and destroy insect larvae in the soil.
Confine them around your fruit trees for a couple of weeks to eat Codling moth, Fruit fly, Carpophilus beetle, Earwigs.
Winter tips: Pests
- Remove drape netting from the trees if you used it over summer. Repair, label, and put your nets away.
- Did you have an aphid problem last year? Apply a hygiene spray of white oil (mineral oil) on any fruit trees that had aphids while the trees are still dormant.
- Put out fruit fly traps in late winter in warm spots in your garden, e.g. near hot water services, sheds, on lemon trees. This will tell you when any adults that have overwintered start to get active.
Winter tips: Diseases
- Monitor apricot trees for bacterial canker and treat with copper spray over winter if required.
- Start monitoring peach and nectarine trees for signs of budswell by late winter. This is the trigger to spray copper to prevent Leaf curl.
- Remove and destroy shrivelled fruit ‘mummies’ from your trees when pruning. These are fungal time bombs that will reinfect your trees in spring
Winter tips: Soil health & feeding trees
- Plant a cover crop beneath existing fruit trees as per green manure (i.e. try to include at least 5 families including legumes), but favour perennial plants over annual.
- Add more flowering plants (and more plants in general) to your understory, and more generally to your garden. Aim for as many plants as possible!
- Review your existing compost system or plan to set up a system in your garden. Or start a worm farm! Worm castings are one of the highest value things to add to your soil. Winter is the perfect time to give your trees a feed.
Winter tips: Growing your own trees
- Save apple, pear, and quince seed for planting later. Separate seed from pulp and keep moist in damp sand. Keep in fridge for best results.
- Take plum cuttings from one-year-old plum suckers growing from the base of plum or apricot trees. Store with the bottom 1/3 of the cutting in damp sand until spring.
- Collect scion wood for grafting from dormant trees. Seal in plastic, label clearly, and store in fridge until grafting time in early spring.
Winter tips: Planting fruit trees
- Select a site and start on soil prep if you have time before you plant your trees. Work up the soil with a fork or spade, add some compost or well rotted manure.
- Plant a quick growing green manure crop to improve the soil if you have at least 6 weeks before you’re going to plant your trees. Water if necessary to help the crop grow quickly.
- If you don’t have time or capacity to do soil prep before you plant a tree, don’t worry! Plant the tree anyway and then work on the soil later. Add some compost, worm castings, or well rotted manure to the hole when you plant your tree but don’t use fresh manure. It’s a good idea to add a handful of rockdust (crusher dust) to help remineralise the soil.