✨ Put down the pruners. The window is closing — and a heat dome is knocking.
This week I'm thinking less about summer pruning as we slide into the back half of June. Tuesday hit 94°F in my yard and the forecast flips to rain by Friday, which is a strange little window where one wrong snip can cost you next spring's flowers. I'm walking the garden with my hands in my pockets and that is the lesson I want to pass along this week. Less is better.
This Week's Action List
- 1
Stop hard pruning rhododendrons, azaleas, lilacs, and forsythia now — they set next year's buds in late June and early July, and any cuts after this week will affect 2027 blooms, and not in a good way.
- 2
Leave hydrangea macrophylla (the big mophead and lacecap types) completely alone through summer. I only remove obviously dead canes; the fat buds forming at the tips right now are your 2027 flowers.
- 3
With Tuesday at 94°F and Wednesday at 88°F, do any remaining shaping at early morning while leaves are turgid and the sun is off the plant — heat stressed cuts die back further and invite borers on stone fruit.
- 4
Skip stone fruit pruning entirely until the dry stretch of late July and August. Pruning cherries, plums, and apricots during this Thursday and Friday rain window is the fastest way to invite bacterial canker into fresh wounds.
- 5
The one thing you SHOULD keep cutting: roses. Deadhead every 3 to 5 days down to the first outward facing 5 leaflet leaf, and strip any blackspot leaves before Friday's rain splashes spores onto new growth.
Frequently Asked Questions
When is it too late to prune rhododendrons in Portland?
The safe window closes in the last week of June in Zone 8b. After about July 1, the flower buds for next spring are already forming at the branch tips, so any pruning past that point removes 2027 blooms. If you missed your April or May window, take only dead wood now and wait until next May.
Can I prune shrubs during a Portland heat wave?
I avoid it. When temperatures push past 85°F, freshly cut tissue dries back further than you intended and the plant is already running on a water deficit. If you must shape something, do it before 8 a.m., water deeply the night before, and never prune on a day forecast above 90°F like this Tuesday.