Ask Annie- Why Aren't My Hydrangeas Blooming

-Emily in zone 4b

Hi Emily- Sounds like you are experiencing a conundrum that has stumped many gardeners alike, especially here in Minnesota! We plant hydrangeas for their showstopping blooms, so why would they put on that big, beautiful show one year, and not the next?

While your troubles could be rooted in light, soil, and fertilizer needs, the most likely cause is due to improper pruning.

First, you need to identify which type of hydrangea you have. In our zone, we can grow four hardy types: Panicle, Arborescence, Macrophylla, and Quercifolia. I recommend always saving your tags or taking note of what you plant in your landscape- it will come in handy one day! Once you’ve identified the variety you have, do a quick search to see what category it falls under.

Once you know what type you have, you can take note of what time of year your hydrangea requires pruning. Panicle & Arborescence hydrangeas prefer late winter- think St. Patty’s Day or April Fools! They are strong performers that bloom on new growth only, so prune lightly to encourage size, or up to 30%-50% of overall growth to maintain shape. Macrophylla & Quercifolia prefer minimal pruning, if any! These beauties will bloom on old and new growth, so pruning is only recommended to control the size of your plant, ideally mid to late summer and no later. These plants tend to be the problem children when it comes to reliability in our Northern gardens. If we experience a colder than average winter (especially with minimal snow), some of those precious buds on the old growth may die off and not perform in spring like you were expecting. You may still see a smaller series of blooms from the new growth mid-late summer.

When it comes to hydrangeas, it is always good to bust out the bloom-boosting fertilizers like Bonide’s PlantTone or FlowerTone in early spring. Apply once in April, and again in late May or early June. Add in some Soil Acidifier if you have a Macrophylla that you want to stay blue or purple!

And remember, gardening is never about perfection, it’s about curiosity, patience, and perserverance! I’m cheering you on as you try new things, learn from the missteps, and celebrate each little success. Until our next chat, happy gardening and keep growing!

-Annie

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