Question
Hello, John
We have a summer jasmine that is about 15 yrs old, but has hardly never flowered.  Is spring/summer, we have green leaves, which are apparently healthy, but only 1/2 doz flowers max. all summer.  the plant is supported on a trellis, and is about 6 feet tall.  full sunshine in the afternoon, but this is sporadic as I live in the NW of England.  Could this be the main problem, or can I try something else?  Thanks, Steve

Answer
Hello Steve,

Greetings to the UK!  I am not sure of what species of Jasmine you are talking about, but the ones with which I am familiar are grown in relatively mild climates, such as the southern US.  The species is _Jasminum officinale,_.  This plant is cold hardy to approximately -5 C with protection.  

If you have been pruning the shrub, this should be done in the spring after you can assess winter damage.  The flowers develop on the new foliage of the current year.  If you have been pruning off the new, green foliage in the late spring, you may be pruning off the developing flower buds.

Some plants may benefit from a root pruning.  This sometimes can stimulate the plant to flower.  Again, this should be done in the late winter to early spring.  This can be accomplished by inserting a the blade of the garden spade into the soil approximately three feet from the plant.  Insert to a depth of approximately 12 inches.  This will stimulate new plant roots.

As you rightfully suggest, low light can reduce flowers also.