Marie Staunton: A little effort pays off
Wisteria needs keeping in check but it's worth it
Published 30/06/2013 | 05:00
I visited the Jack and Jill Children's Foundation garden – by Kildare Growers in association with Peter O'Brien Landscapes – at Bloom earlier in the month. It caught my eye because of the small yet lovely standard wisteria.
I started one off in a pot last year and aspire to having a very fine-looking wisteria in a few years' time. It does take a bit of work to get it to a stage where it will look impressive, but I'm in for the long haul and it should be well worth the wait.
There are two main types of wisteria available to gardeners, one is Japanese and the other Chinese. Both are equally beautiful, but the Wisteria sinenis 'Prolific' has soft lilac-blue flowers that seem to appeal to most gardeners. These are grafted plants to ensure good flowering.
It is better to buy named varieties, otherwise, it can be a bit hit and miss with both the strength of colour and flowering ability.
As with a lot of flowering plants, pruning is vital – if wisteria is left unchecked, you will find that the more vigorous rootstock will take over, producing foliage at the expense of flowers.
This is a plant that responds really well to very hard pruning. If you have just purchased a wisteria, then start as you mean to go on with twice-yearly pruning.
After flowering has finished, you will need to tie in the new shoots to create a framework for your plant. The same applies if yours is a newly planted one, so August is the right time to do this job. The new lateral shoots will have formed and you need to secure them into wires or a trellis. These shoots will become your branch framework in a few years' time and this is where your flowers will appear.
All the other shoots that you don't need for creating your basic framework will need to be taken back to 30cm from the stem or branch that they appeared from.
The reason you are pruning at this stage is to get light into the framework of the plant; this, in turn, helps the new young stems to ripen.
You will probably get some whippy growth after you prune because there should be plenty of heat around right into September. Just cut any of the fresh growth back to about five buds from the main stem. The buds are the little swellings on the stem.
The leaves will fall in autumn and you will be able to see the framework at this stage – you might need to run a few more support wires along the wall in order to tie in new stems next year.
In February, it will be time to prune back even harder – all the stems will need to be shortened to about 5cm from the old wood. The more mature wood on the plant is a grey colour, which will help you to distinguish it from the newer growth.
Have a look at your plant at that stage and you should be able to identify the slightly swollen flower buds that are going to produce those gorgeous flowers during the summer.
I know it sounds like an awful lot of hard work, but it really is just timing. If you are a tidy sort of person, then this is the ideal plant for you to keep in check.
Reading about how to do something is a lot harder to take in than seeing it being done, but once you've made the effort to prune this plant twice a year you'll never look back. And after all your hard work, you can sit down and dodge the showers with a nice cup of tea – ah yes, the joys of an Irish summer.
In the same garden, French lavender was planted en masse and it creates a fabulous display of subtle colour. Again, it is a candidate for pruning, which should be done after the flowers have faded and the new growth is underway.
Even though we have pruned lavender back very hard in the past to rejuvenate older plants, it is advisable to prune it yearly and never into the old wood.
Experience will teach you to look for new shoots lower down the stems if you find yourself having to drastically cut them back for any reason.