Glorious Hydrangeas

Garden Clippings for August 31, 2019

The winner, hands down, in the summer garden is the Hydrangea.  Their bold blooms mostly in white, but also in shades of pink, red and blue, begin flowering in July and continue blooming well into September.  In the world of flowering shrubs, Hydrangeas give most bang for the buck.

Hydrangeas are easy to grow.  Give them a spot in partial shade and they will thrive.  Some varieties will grow in full sun, but most prefer the east or north side of the house where they can find 4 to 6 hours of sunlight.

If Hydrangeas could choose between sandy and clayey soil, they would choose the latter, because clay soil has more moisture holding capacity during dry summer months.  Hydrangeas love moisture but don’t enjoy waterlogged soil.  In spring and fall they will get enough rain from above, but in July and August, they’d like extra water.  it is a good idea to cover the soil with a layer of mulch to help retain soil moisture.

Hydrangeas love fertilizer and would appreciate an annual dose of compost, triple mix or manure worked into the top layer of soil.  A spring fistful of granular fertilizer with a balance of nitrogen, phosphorous and potash will encourage healthy growth.

Occasionally, Hydrangeas refuse to bloom, with the blame likely falling on one of 4 factors.  For starters, Hydrangeas, like humans, need to be mature before they bloom and will often not flower until they are 3 to 5 years old.

Hydrangeas can tolerate a lot of shade, but if they are in deep shade, they will concentrate their efforts on vegetative growth rather than flowers.  For best performance, Hydrangeas would like 4 to 6 hours of sun preferably in morning or evening.

Most Hydrangeas are tough as nails, but a few varieties hardy to the climactic zone of 5, may have their buds frozen off if they experience a spell of bitter cold.

Hydrangeas really don’t need to be pruned, but sometimes the gardener cannot resist tackling their shrubs with a pruning tool.  Pruning at certain times of the year may jeopardize flower production for the following summer.  Hydrangeas that fall in the Panicle and Smooth categories will bloom on the current year’s growth and can be pruned in fall or spring without affecting bloom production.

Hydrangeas in the Big Leaf, Mountain and Oak Leaf category set their flower buds in the previous summer and may flower poorly if pruned anytime during the previous year.  If you don’t know the name of your hydrangea consult a guidebook or the internet to determine pruning recommendations.

To make matters complicated, some new Hydrangeas will bloom on both current and last year’s growth.  The Let’s Dance, Endless Summer and Tuff Stuff series fit into this group.  To prune these Hydrangeas, I recommend taking a hand pruner and removing much of the oldest growth, leaving the younger more vigorous stems to do the blooming.

If in doubt, just leave the pruning tool in the garage and your Hydrangea will surely bloom.