Climbing Hydrangea

(Question)

I planted a Climbing Hydrangea (anomala patiolaris) about 7 years ago.  Beautiful leaf growth over an archway and up the sides of my garden shed, but no flowers.

Is this normal?

Is there anything I can do (soil amendment) to ‘encourage’ it to bloom?

(Answer)

It sounds like you have a lovely healthy plant even though you’re not yet getting flowers.  There are a few reasons this could be happening, maybe one or in combination.

Improper siting – Hydrangeas like rich moist soil but if you have a heavier clay based soil, adding compost / organic matter will help with feeding, soil structure and moisture retention.

Lack of water – Hydrangeas are thirsty plants and on hot days their fleshy leaves and stems call for all the water they can get.  Installation of a drip irrigation hose on top of the soil around the plant would be very helpful.  Generous mulching would also help retain moisture in the soil.  Even thought they need lots of water, these plants like soil with good drainage so that their roots are not standing in water.

Light requirements – Hydrangeas will bloom in sun but if the plant is exposed to too much hot sun the foliage and plant can become stressed.  Morning sun is ideal with some afternoon shade to relieve heat stress during the hottest part of the day.  Also, Hydrangeas will not bloom consistently in deep shade.  If either of these issues affect your plant, you may have to transplant it in the spring.

Pruning – Climbing Hydrangeas are woody, slow growing vines that bloom on old wood so pruning at the wrong time may be the reason there are no flowers.  Pruning should be done in late June or early July in order to let the plant form flower buds for next year.

Feeding – Hydrangeas that are being fed with a high nitrogen (N) fertilizer will grow lush green foliage and not produce flowers.  This can inadvertently happen if a nearby lawn is being fed with a turf fertilizer.  It is best to feed your plant with organic matter such as compost or sheep manure.

One last word of encouragement, these plants are slow growing and can take many years to reach a mature state where they bloom prolifically.  Be patient and you will be rewarded.