Pruning of rhododendrum and azaela plants - Ask Extension
Can you please provide guidelines for pruning an overgrown rhododendrum and azaela plants?
What temperature is best to do the pruning ? I was told...
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Pruning of rhododendrum and azaela plants #880983
Asked August 10, 2024, 11:25 PM EDT
Can you please provide guidelines for pruning an overgrown rhododendrum and azaela plants?
What temperature is best to do the pruning ? I was told best not to prune on a very hot day.
Is it necessary to test the soil for acidity?
Thank you!!
Prince George's County Maryland
Expert Response
Hello; Thanks for submitting your garden and landscaping questions to the University of Maryland Ask Extension Service.
First; see this UMd Extension webpage on the care of Azaleas and Rhododendrons: https://extension.umd.edu/resource/azaleas-and-rhododendrons-identify-and-manage-problems/.
Now, on to pruning; See this UMd Extension webpage on pruning your azaleas and rhododendrons: https://extension.umd.edu/resource/pruning-shrubs-and-hedges-home-garden/. See the section 'When to Prune' as it is late in the season for pruning your spring flowering shrubs. It would be better to wait until just after flowering in mid-late spring that you can prune back your azaleas and rhododendrons. You can prune in early spring but you would cut off flower buds and potentially get no flowers, but your shrubs would be able to bloom in following years.
Do NOT prune now as this could lead to tip burn when autumn frosts injure tender new foliage that may emerge after any attempt at fall pruning. And the general rule for pruning any shrub or tree is to remove at most only 1/3 of the outer foliage and branches in any one year.
Good luck in your gardening efforts. Thanks; Christopher
First; see this UMd Extension webpage on the care of Azaleas and Rhododendrons: https://extension.umd.edu/resource/azaleas-and-rhododendrons-identify-and-manage-problems/.
Now, on to pruning; See this UMd Extension webpage on pruning your azaleas and rhododendrons: https://extension.umd.edu/resource/pruning-shrubs-and-hedges-home-garden/. See the section 'When to Prune' as it is late in the season for pruning your spring flowering shrubs. It would be better to wait until just after flowering in mid-late spring that you can prune back your azaleas and rhododendrons. You can prune in early spring but you would cut off flower buds and potentially get no flowers, but your shrubs would be able to bloom in following years.
Do NOT prune now as this could lead to tip burn when autumn frosts injure tender new foliage that may emerge after any attempt at fall pruning. And the general rule for pruning any shrub or tree is to remove at most only 1/3 of the outer foliage and branches in any one year.
Good luck in your gardening efforts. Thanks; Christopher
