This year the National Plant Collection of Wisteria in Surrey was badly affected by a late frost in April, and flowering was non-existent, but the new growth still needed its summer trim. Summer pruning helps to expose the wood, allowing it to ripen and improving flowering the following year.
Last week, Marian Badger and I spent a very satisfying and companionable couple of hours pruning the standard specimens. Side shoots were taken back to five or six buds and the leaders reduced by about half, taking into account the overall shape of the specimen. Some late flowers were left to compensate for the loss of blooms earlier in the year.
As we worked Marian told me that a ‘common’ name for Wisteria is the ‘two and six’ plant because it should be winter pruned in February and then tackled again in June. In the ‘sunny’ south east this second pruning can be delayed as there should still be enough sunshine to allow the ripening to take place. Googling the term I found an article by Matt Biggs referring to this name, but attributing it to the number of buds left on the laterals after pruning, six in the summer pruning and two in the winter. Whatever the provenance of the name it’s a charming reminder of pruning techniques.
Other members of the Surrey group will be helping to complete this job and if you are interested in lending a hand, give us a ring at National Office, 01483 447540 or send an email to firstname.lastname@example.org and we will pass your details on to Marion.