Growing
A Pruning Cut Never Actually Heals — the Tree Seals It Off Instead
Wound paint and pruning sealants don't help a tree 'heal' a cut faster because trees never heal wounds in the animal sense to begin with.
Trees respond to injury through a process called compartmentalization: they wall off the damaged tissue with chemical and physical barriers, preventing decay and pathogens from spreading into healthy wood, while new growth rings form around the outside of the wound over subsequent seasons. The original damaged cells are never replaced or repaired — they're sealed in place, permanently, inside the trunk.
Because of that, wound paints and pruning sealants, once standard practice, are now generally discouraged by arborists — research found they can trap moisture against the cut and interfere with the tree's own compartmentalization process rather than assist it. A clean cut just outside the branch collar, left alone to callus naturally, heals (compartmentalizes) more reliably.
Put this into practice
More facts like this
- Most Companion Planting Folklore Has No Evidence — A Few Pairings DoMechanisms like shade, trap cropping, and physical barriers hold up in trials; vague 'improves flavour' claims do not.
- Removing Tomato Suckers Is a Trade, Not a Free UpgradeAggressively suckering an indeterminate tomato produces bigger fruit sooner, at the direct cost of the leaf cover that prevents sunscald.
- Marigolds Don't Repel Most Garden Pests the Way Gardeners AssumeThe marigold pest-repellent reputation is a real, narrow finding stretched into a much bigger claim than the evidence supports.