Fungicide post-winter storage

Hello all. I’m in Zone 5b here in Chicago. Feedback please — currently have deciduous and conifers in an unheated, unattached garage. Is it recommended to prophylacticly use a fungicide once they’re brought outside from storage? If yes, particular brands to use? If applicable to the question, garage temps with thermostat has been kept between 33-35 F except for sub zero days when heaters couldnt keep up and watered as need throughout winter. Thanks…


I am in Toronto (also zone 5) and keep my deciduous conifers (such as Larch, Larix laricina) in an unheated garage. Some people do use fungicides prophylactically but there is a bit of a movement to focus on the health of the tree instead and stay away from chemicals as much as possible. I rarely use chemicals and instead try to find out why a tree has a particular disease - so I don’t spray them in advance. You probably know that Ryan has recorded a few podcasts about focusing on the health of trees and basically using chemicals as a last resort. I am currently refreshing my knowledge about horticultural by taking online courses at a University and I ran across a great stat - over 80% of pests (fungus, bacteria, virus) on plants result from abiotic factors that weaken the plants. It sort of makes intuitive sense - we provide a tree with too much sun, too much water/dampness, too much fertilizer etc. and next thing we know the trees weakens and disease occurs. Hope this helps.

@GaryO thanks for the amazing feedback. Yes, being pragmatic that stat does make sense. Have a great 2023…!

happy to help - I don’t go on the forum often (so many other things to take care of but recognize the forum is a wonderful resource) but did notice your posting on the weekly email - have a great weekend.

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