Suggestions for prepping your hydrangeas for spring development

I planted lots of hydrangeas in my backyard final 12 months and would love some pruning recommendation.

— Jodi Baumann, Gurnee

It is a good time to prune a lot of the hydrangeas grown within the Chicago area whereas the crops are dormant. Since your crops are newly planted, there may be little or no if any pruning so that you can do that spring. You need to end this pruning earlier than the crops begin rising with constant heat climate later in spring. In previous years when the nice and cozy climate got here on shortly, I needed to prune some hydrangeas because the buds had been beginning to open. In these conditions, I used to be not in a position to lower the shrubs again as aggressively as I’d have preferred as a result of they had been too far alongside in improvement. There may be nonetheless time this winter to finish this pruning.

Easy hydrangea cultivars such because the generally grown Annabelle and Abetwo (Hydrangea arborescens) reply effectively to being aggressively reduce within the dormant season. I desire to chop them again at floor degree or to about 1 inch above. Reduce thicker stems again to floor degree to open house on the base for brand spanking new stems to develop. This can end in extra compact crops. I’ve discovered it greatest to chop much less vigorously rising cultivars resembling ‘Invincibelle® Spirit II’ again extra gently. I’ve been reducing my ‘Invincibelle ® Spirit II’ hydrangeas again by a 3rd to a half with good outcomes. Some Anabelle hydrangeas rising in my backyard beneath oak timber had been underperforming with annual pruning to floor degree. That they had extra foliage and elevated flowering after I stopped pruning them so aggressively and simply nipped again the ends of branches. The shade and root competitors from the timber was limiting the expansion response of the hydrangeas.

Panicle hydrangea cultivars (Hydrangea paniculata) are additionally generally grown and reply effectively to pruning presently of 12 months. The dwarf varieties want little or no pruning to take care of good type. The bigger rising varieties resembling ‘Tardiva’ will be pruned again every year if you wish to keep them at a extra compact measurement in your backyard. I’ve gotten good outcomes pruning again younger panicle hydrangeas to about 3 toes above the bottom every year. This retains the shrubs to a extra compact measurement within the panorama. Reduce them again much less aggressively if you wish to keep a bigger shrub in your backyard. I’ve not gotten good outcomes when aggressively pruning again very massive panicle hydrangeas that haven’t been pruned for a few years. It’s best to progressively work at decreasing the dimensions of those crops over a interval of three to 4 years. There are sufficient cultivars obtainable now to decide on a plant with a measurement that matches your wants with out intensive pruning.

Oak leaf hydrangeas (Hydrangea quercifolia) flower on previous wooden, so it’s best to keep away from pruning them in winter if you wish to have flowers this 12 months. If the crops are misshapen or overgrown, it’s possible you’ll wish to prune them extra aggressively now to appropriate their construction and sacrifice flowers for summer time.

Bigleaf hydrangea cultivars (Hydrangea macrophylla) usually want little pruning. Generally they’re mistaken for clean hydrangeas within the winter pruning season. The newer cultivars resembling ‘Infinite Summer time’ flower on previous and new wooden. There tends to be extra winter dieback on these hydrangeas, so it’s possible you’ll find yourself pruning out lifeless stems later in spring. When you’ve got a cultivar that flowers on previous wooden, you’ll have decreased or no flowering as a result of winter kill of the stems or a mistaken arduous prune.

For extra plant recommendation, contact the Plant Info Service on the Chicago Botanic Backyard at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture on the Chicago Botanic Backyard.