Healthy Apple Calendar

January — Dormancy and inspection

What to do

• Remove dead, broken, and obviously diseased branches in dry weather without hard frost.
• Take down any mummified fruit still on the tree.
• Look closely at the bark, twigs, and buds for overwintering pests.
• Clean and put your pruning tools in order.

Why

Dead wood and mummified fruit are where disease overwinters and returns to the tree from. The less is left, the calmer the spring.

Common mistakes

• Pruning in a freeze or wet weather.
• Doing things out of habit — just because it is done every year — without knowing what is actually on the tree.

February — Winter pruning

What to do

• Prune in late winter, in dry weather. Take out dead, broken, and diseased wood first.
• Make clean cuts at the outer edge of the branch collar so wounds heal faster.
• Open the crown so light and air get in.
• Carry the prunings out of the garden and do not leave them under the trees.

Why

When you prune in late winter, the wounds are open only briefly before spring. An open crown dries faster after rain, and that lowers the risk of diseases that need long periods of leaf wetness.

Common mistakes

• Pruning too hard — it upsets the tree’s balance and triggers vigorous shoots.
• Leaving prunings lying in the garden.

Tip: Prune by the tree’s condition and the weather, not by the calendar date.

March — Buds start to develop

What to do

• Active monitoring starts here. Watch for scab, powdery mildew, and overwintering pests.
• Keep track of rainfall and long periods of wet leaves: they are the main signal of scab risk.
• If you didn't collect or shred last autumn's fallen leaves, do it now.
• Follow the bud stage, not just the date.

Why

The scab fungus overwinters mainly in fallen, infected leaves. In spring rains, spores are released from them. Infection needs the leaves to stay wet for several hours, and for longer when it is cool.

Common mistakes

• Waiting for visible spots before doing anything.
• Ignoring the weather.

Tip: Prevention before infection is far more reliable than trying to rescue a tree that is already heavily infected.

April — Pink bud and bloom

What to do

• One of the most important periods for next harvest. Watch for scab, powdery mildew, apple sawfly, aphids, European red mite, and leafrollers.
• In warm, humid weather during bloom, also watch for fire blight: it infects the blossoms.
• Protect pollinators: bloom is the bees’ time.
• Don't overdo nitrogen — it pushes lush, soft growth, which fire blight favors.

Why

Blossom infections and the first damage on fruit set decide how much fruit there will be. Fire blight overwinters in cankers on branches, and spreads at bloom through rain, insects, and wind.

Common mistakes

• Acting "because it is April" without identifying a specific problem.
• Working in the canopy during bloom when it can be avoided.

Tip: If you recognize fire blight, prune the branch 8–12 inches (20–30 cm) below visible signs, in dry weather, and disinfect your tool between cuts.

May — Petal fall and young fruit set

What to do

• A critical period for the coming fruit. Watch for scab, powdery mildew, codling moth, apple sawfly, aphids, mites, and leafrollers.
• For codling moth, use pheromone traps: hang them around bloom at eye level and check them every 2–3 days.
• Note when the first sustained catches appear — that tells you when the flight has started.
• Thin the fruit set if it is too dense, and remove fruit with visible damage.

Why

"Because it is May" does not help with codling moth. The right moment to act is set by the pest’s flight and development, so monitoring matters more than anything else.

Common mistakes

• Acting by date instead of by observation.
• Ignoring fruit that was damaged from the start.

June — Fruit grows

What to do

• Keep monitoring for codling moth, mites, aphids, scab, and powdery mildew.
• Look over the young fruit for damage and promptly remove infested fruit so the pest does not develop in it.
• In dry spells, water deeply and evenly rather than a little every day.
• Check your traps and note the catches.

Why

The conditions that favor disease — long wet spells — remain a risk in June. Promptly removing infested fruit reduces the number of pests in the next generation.

Common mistakes

• Relaxing because bloom is over.
• Leaving damaged fruit on the tree and under it.

July — Don't stop watching

What to do

• It is a big mistake to assume the work is done once fruit has formed. Keep watching for later generations of codling moth, mites, fruit rots, and damaged fruit.
• Watch for sunscald on the fruit and for water stress in dry weather.
• Not every spot is a fungal disease. Not every deformed fruit is pest damage. Not every yellow leaf means a nutrient shortage. Find the cause first.
• Stop nitrogen feeding after the start of July, including compost and manure.

Why

Late nitrogen pushes new, soft growth that does not harden off before winter. And misidentifying the cause leads to the wrong action.

Common mistakes

• Treating every spot as a fungal disease.
• Nitrogen in the second half of summer.

Tip: Take a close-up photo of the problem and compare it with guides before reacting.

August — Ripening

What to do

• Watch for fruit rots, late pest damage, late infections, cracking and other physiological disorders, and sunscald.
• Collect fallen and rotten fruit and carry it away; do not leave it under the tree.
• Keep moisture even in dry spells — big swings lead to fruit cracking.

Why

The closer harvest gets, the more fruit rots become a risk. Rotten fruit under the tree becomes a source of new spores.

Common mistakes

• Leaving rotten fruit on the ground.
• A sharp swing from drought to heavy watering.

September — Harvest

What to do

• Pick fruit when it is ripe for the variety, not by the date.
• Handle it gently: bruises and wounds lead to rot in storage.
• Separate damaged and rotten fruit and do not put it with the sound fruit.
• Note which varieties and which trees had the most problems.

Why

Bruises and wounds are the entry point for rot in storage. Your harvest notes show where to focus attention next year.

Common mistakes

• Picking everything on one day regardless of variety.
• Mixing sound and damaged fruit.

October — After harvest

This month

What to do

• The apples are in, but preparing for the next crop starts now.
• Collect or shred the infected leaves; if there are only a few, rake up the fallen leaves around the tree.
• Take mummified fruit off the tree and off the ground.
• Remove clearly diseased and damaged parts in suitable dry weather, and inspect the trees for wounds and cankers.

Why

The smaller the infectious load you leave to overwinter, the better the starting position next spring. Fallen leaves are the main overwintering source of scab.

Common mistakes

• Leaving fallen leaves "as mulch".
• Leaving mummified fruit on the branches.

Tip: If you use your compost around the garden, do not add infected leaves to it: home compost often does not get hot enough to kill the pathogen.

November — Getting ready for winter

What to do

• If you didn't shred the leaves in October, do it now: orchard research shows shredding leaves in November or April sharply cuts spring spores.
• Check the trunks for wounds and cankers and clean them up in dry weather.
• Avoid late-fall pruning, apart from removing dead or broken branches.
• Clean and put away your tools.

Why

Orchard studies show that shredding leaves in November or April cuts spore numbers sharply. For a small home tree, collecting and destroying the leaves is enough.

Common mistakes

• Heavy pruning in autumn — it raises the risk of winter injury.

December — Time to take stock

What to do

• Write down what happened this season: which problems you had, when they started, and what the result was.
• Note which trees and varieties did well.
• Plan the pruning and inspections for next year.

Why

That way you don't start next year from zero. The best program is not the one with the most interventions, but the one that starts with sanitation and good pruning, then continues with steady monitoring and early recognition of problems.