Pruning Mock Orange

[ploppygb]

My Mock Orange is currently in bloom, although the flowers are looking a bit sorry for themselves after all the rain. I'm wondering what to do about pruning this plant, largely because it has new stems without flowers on them, that extend about 3 to 4 feet about the main body of the plant. Frankly, it looks a bit daft. I'm not sure whether to cut this new growth back the level of the old stems to make it look tidy (and whether this is the right time of year to do it anyway). I think I read that this year's growth is what blooms next year so I don't want to ruin that. I'd appreciate any advice. Thanks.

[David Hare-Scott]

I have one that always sends up long leaders with few leaves every year. I cut them back to around the length of the bushier stems to make the whole thing more compact each winter.

D

[echinosum]

This new growth is indeed potentially next year's flowering growth. However if you want it bushier you can shorten it now, and it will continue to produce bushier new growth that will flower next year.

[David E. Ross]

Are you asking about some species of Philadelphus or about Pittosporum tobira? Both are commonly called "mock orange".

I can't help you with Philadelphus. I prune my Pittosporum tobira shortly after flowering about once every 3-5 years, when they reach the height of the eaves of my house. I cut them quite short, into bare wood. They resprout quickly and usually flower the very next year.

A public garden near my house has many dwarf Pittosporum tobira, which they shear several times a year to maintain a ball-like appearance. I think this is excessive since they rarely flower. For two years now, purple-leaf plum trees (Prunus cerasifera 'Altropurpurea') at that same garden have been pruned in mid or late summer, after the following year's bloom wood has formed; these trees flower very poorly.

The conclusion is that timing is important. In general -- but definitely not universal -- woody plants that are not grown for fruit and that flower in the spring should be pruned immediately after flowering.