Climbing hydrangeas that don’t climb

I have had two climbing hydrangeas for over seven years without a single bloom.

They are in a bed at the back of the house with a trellis for each. I believe they get enough sun. Other plants such as hostas, ferns, Solomon’s Seal etc. do just fine there.

I am considering moving them but they fill in a spot that could be wonderful if I could get some blooms from them. What do you think?

This is a common issue with the true climbing hydrangea, Hydrangea anomala subsp. petiolaris. It makes a beautiful vine with rounded, serrate-edged, lustrous green leaves and flaky, cinnamon exfoliating bark.

As a young plant it can be painfully slow to grow but will clamber up walls, trees and trellises by self-clinging rootlets over time. Eventually it will transition to a shrubbier growth habit, often not until it has reached 8- to 10-feet tall. It is when it reaches this stage that it will really begin flowering. I have often grown the vine for about 10 years before it begins to flower; so patience is your best ally. If you don’t possess that patience, try the false climbing hydrangea, Schizophragma hydrangeoides, which looks similar but flowers at a much younger age.

Red spots on my star jasmine

My jasmine was a disappointment this year. The leaves had tiny red dots on them and the blooms turned brown too early. What should I do?

I’m assuming you are talking about star jasmine, Trachelospermum jasminoides, an evergreen vine with sweet smelling white flowers. Red spots on the leaves are typically indicative of Cercospora leaf spot. This fungal disease appears usually when conditions are warm and wet which was certainly how our summer began. The much wetter than normal early summer conditions were excellent for many fungal problems and we saw them explode this year. I would try to remove as much of the infected material as possible, rake away fallen leaves and mulch this winter. Assuming conditions are different next year, your plants should recover.

When to prune a gardenia

My older gardenia bush never recovered from the cold winter two years ago. It has greenery but the blooms are sparse. How far back can I prune the plant and when should I prune it?

Most older gardenia flower heaviest in the early season from buds they form in the fall. Pruning now will remove those buds and reduce flowering next season. Some of the more modern selections bloom off and on throughout the season and so removing buds now will only delay flowering next season. In general, I recommend purning gardenias every two to three years after they flower in late spring or early summer. For best results, thin out some branches and reduce the height by about a third. I have seen gardenias pruned back very hard and recover beautifully but I have also seen plants die after this treatment.

This story was originally published October 7, 2016 at 10:29 AM with the headline "Climbing hydrangeas that don’t climb."