Pruning Wisteria is not essential where they have room to roam and colonise a wall frame or sturdy trellis. Wisteria will wander and flower in this situation without any pruning. However, if the Wisteria is growing in a confined space, or at least needs to be constrained, then pruning will be necessary as set out below.
If you want the best flowers on your Wisteria, then it is important to prune your Wisteria, and prune your wisteria at the right time. We show you when to prune wisterias, and also how to prune wisterias.
Wisteria is a strong growing vine, and will soon become a tangled mess if left to its own growing habits. As we tend to grow wisterias as ornamental plants climbers then protocol decrees that they should be kept under control!
Autumn or early winter pruning of wisterias simple brings the rapid summer growth into some manner of tidiness, and will most certainly allow for easier pruning in the early spring. Whilst pruning wisterias in the manner set out below is best, the second best option is for trimming wisterias with a good hedge clipper. That will at least allow for easier access in later winter.
To keep Wisteria under control they should be pruned twice each year. Prune like this to ensure maximum flower and the pruning will also keep your Wisteria within set limits!
Prune wisteria in the autumn by pruning all of the current side-shoot growths back to within 30-40cms of the main lateral branches. This should leave 4-6 leaves or leaf buds on each side-shoot. Any side shoot required to extend or train the framework should be left and trained as required and not be pruned!
In January-February, cut back Wisteria side shoots back even further - 6-10cm long, leaving only 2 or 3 buds on the side-shoot. These will be the flowering spurs on your wisteria. There is no need to prune the wisteria to an outward facing bud.
These pruning operations should be carried out each year. The only shoots to be left 'unscathed' are those which are required to extend the size or direction of your wisteria.
Any lateral training of the new lateral framework needs to be done at this time unless it was completed with the autumn trimming session
How to prune wisteria side shoots to encourage flowering instead of new stem shoots.
A wisteria side shoot - lateral, ready to be cut back hard in late winter pruning (Jan/Feb).
The lateral - having been cut back to 3 buds from the main branch leader. The pruning cut is immediately above a bud.
This will allow the flower buds - which are on the older wood nearer the main stem - to receive the food reserves which are surging up through the vine at this time. If these shoots are left un-pruned, as well as developing into an untidy mess, the 'goodness' will be allowed to creep up through the shoot and give even more growth, both hiding the flowers, and depriving the flower buds of the wisteria the food reserves.
A great specimen of wisteria, that has been pruned correctly. learn about the general care of Wisterias here.
Regular Pruning of this wisteria is essential, for whilst it has the space to roam unhindered, the pathway below would soon be rendered unusable as the wisteria would soon take over the whole arch.
How to Prune Wisterias. A tidying-up operation in autumn, followed by hard pruning your wisteria in the late winter
When to Prune Wisteria October is the optimum time for the autumn pruning of wisteria. Most of the foliage will have dropped. February is the good time for winter pruning but no later than early March. The main reason for pruning wisterias in the manner described above, is for all of the energy of the plant to be focussed on the flower buds - near the main stem, and not diverted into the stem growth system at the expense of flowers. If you decide not to prune your wisteria, then over the years the flowers on the plant will become smaller - for the energy will be focussed on providing new stem growth. So, prune you Wisterias regularly to be sure of larger flowers.
Wisteria are easy to grow - once you know how! We give you advice to help you grow a wisteria - maybe two - that will be the envy of your neighbours, and be the talking point of your locale! They are often associated with stately homes - being the majestic climbing shrubs that they are, but there are many places they can be grown.
Although grown as a vigorous climber, wisterias can be adapted for planting in pots, as small weeping trees or additional attraction through a tree or even for covering up an unsightly object, such as an old tree stump.
I have also see them growing 'horizontally' over a low frame, which of course does not do justice to the drooping racemes of flowers!
Whilst Wisterias are very tolerant of where they are planted - and generally hardy - it is good to remember that most originated in damp woodland and on the banks of streams in many areas of Asia. They are often planted against house walls - prone to drying out and causing several cultivation problems. If planted in such a situation, then there should be plenty of organic matter placed into the hole before planting, together with which, an annual mulch of peat or compost/leafmould is recommended.
Hard frosts can sometimes damage the flower buds, so Wisterias are happiest when not planted in an easterly aspect. The early rising sun can damage the frosted buds by 'thawing' them too quickly. A South facing aspect is best if planted against a wall.
In any event, in all but the most sheltered, mildest areas, the winter mulch to protect the root system is advisable.
They are admirable for planting near a tree and being allowed to find their own way up - with a little help and guidance. A few straining wires or a stout pole gets them up to the lower branches. After that, they can fend for themselves. Little on no training is required - certainly no pruning. Trees such as Silver Birch and Robinia Frisia are best types - not too dense foliage canopy - especially in the late spring, early summer when the Wisterias normally flower.
Whilst they are predominantly climbing plants, wisterias can also be grown as stand alone small tree - though they will need support for this. The trunks are handsome if grown like this. If you are going to grow as a standard tree, it will need a good hefty stake to see it through the first few years. Thereafter, the top growth of your standard wisteria will also need some sort of frame support.
Along the top of a high wall is another ideal place - as is along the top of a sturdy fence. Modern lap panels will not be suitable for the rambling growth. Having said that, I have seen a wisteria as the main support for an otherwise decrepit rustic pole fence.
They make stunning dividing fences if grown along tensioned wires. Once trained, they are easy to look after in this situation, and as a light screen next to a patio or deck, the foliage of the wisteria - together with the lightly scented blooms with make for a superb feature along one side.
Wisteria are happy in full sun or light shade. With the latter, like so many other climbing shrubs, they are best if can scramble up to the sun. Certainly looking their best in full sunshine of the flowers.
In the case where it is impossible to break through concrete etc to plant your wisteria into the soil, then they can be grown in a large container pot of your choice. Make sure that the pot is substantial, for if perchance it breaks or cracks, then it will be a difficult task to re pot - mainly because the trunk and branches will be attached to some structure or whatever.
An advantage of growing a wisteria in a pot, is that the growth will normally be restricted somewhat.
Use a good potting compost, with added organic matter at time of planting - incorporate some Osmocote fertiliser to get the vine off to a good start. It would also be a good idea to add some water retention crystals/gel, to help with moisture retention. Bear in mind that the summer months will need extra care, to ensure enough moisture required for the production of the next year's flower buds. Do NOT let it dry out.
It will help if the pot is placed either in a shaded spot, or to be surrounded with low growing shrubs in containers to keep the sun from heating the compost and therefore the plant roots too much.
The trunk is generally the main support once established and trained. Against a wall, the wisterias are best grown and trained to strong galvanised wire stringers. This is essential in the early days (years) of training against a wall. The main trunk of an established wisteria vine can be several inches through, with the lateral frameworks also having hefty branches.
If planting your wisteria to grow up a trellis, then again ensure that the structure is sturdy enough to support the mature plant. It will be virtually impossible to replace a rotted trellis that has a Wisteria growing though it. See How and When to Prune Wisteria.
Pergolas are an option, or sturdy arches. If you are to grow a wisteria on a pergola, then make sure that the structure is up to the job, and well treated with a good timber preservative before attempting to grow in this manner. You will hardly be able to remove the main trunk or mature branches to re-treat with preservative! A wisteria over the top of a mature brick or stone arch is a dream for most - but a gorgeous reality for others. Wisteria Arbours are the stuff of romantic novels, but a practical proposition nonetheless. What better on an early summer evening than relaxing midst the fragrant spring blooms all around you.
In all situations where the wisteria is to be trained - more or less everywhere except up a tree - good sturdy fastenings are required, with the galvanised wires being the preferred options. They should not be 'wired' to a frame, for if forgotten, the wires will cut into the branch and cause damage and loss of many years growth.
Against a house wall, Wisterias are not too much of a problem insofar as biting into the mortar is concerned. They are not self-clinging, so rarely do any damage to the wall. The same is true of worries about subsidence. Certainly modern house foundations will not be presented with any problems, neither surrounding footpaths with roots.
Wisterias are often forgotten about - except for the two times of pruning - and of course flower time. They are generally trouble free, but should be well watered during periods of prolonged drought. Pruning of wisterias is not the problem is is made out to be. Our guide will point you in the right direction, and ensure that you get the best flowers from your climbing shrub.
As with many climbing plants, wisterias are often forgotten when it comes to feeding! Normally, and annual dressing of Bone meal in early spring will be enough. Another option, is to apply a long term slow release such as Osmocote. This will ensure that your climber has ample fertiliser for the whole season. Don't overdo it. Bear in mind the origin of the Wisteria - damp woodlands or banks of streams - generally with rich fertile soils! In spite of that, they thrive against walls and dry soils.
There are not too many problems with Wisteria that good scare and attention will not sort out - or even prevent. Lack of flowering is normally as a result of incorrect pruning, but also from allowing the plant to dry out during June July through till September. These months are crucial for the formation of flower buds for the next spring. It is at this time during mid summer that they will need to be watered to allow for the flower bud growth.
Another - more common - cause of lack of flower, is where the plant has been bought as a seedling. (You will not be made aware of this of course) Generally any Wisteria in a pot smaller then 3-4 in (10cm) will be a seedling of the wild plant version,. These can either never flower (They normally get discarded) or can take 15 to 20 years. Named varieties are normally grafted onto these wild seedling rootstocks to give them more vigour - and to get them to the selling stage much quicker!
Insects Scale insect can be a problem sometimes - though rarely. Aphids also.
Various root rots can be problematic - though not common. The worse being the fungal Honey Fungus Disease - Fatal!
Leaf spot - either brown or black patches, can be troublesome (only) in dry summers. Keep the plant generally healthy with regular autumn/spring mulches, together with annual dressing of bonemeal, to help keep fol,iage problems at bay.
Basically DON'T try to move your wisteria, unless it is no more than a year old. They resent transplanting, and care should also be taken at planting time to ensure no root disturbance.
Bonsai Wisteria. Seedlings are good material for growing wisterias as Bonsai Trees. The normal methods of growing Bonsai apply to growing Wisterias as Bonsai, but one would normally grow them in miniature tree form rather than as a miniature climber. The branches respond very well to bonsai pruning.
Poisonous Be aware that the seeds of Wisteria are poisonous - certainly causing upset stomach if ingested. Wisteria is the same family as Laburnum - Leguminosae. So many of this family's seeds are poisonous. (Except our edible beans and peas of course!)
Grafting onto seedling rootstocks is the normal way for producing named varieties of Wisterias, but it is also possible to have success with basal softwood cuttings in early summer. The success rate is not great and a little bottom heat - such as a heated propagator will certainly help. Otherwise, spare a new growth in your autumn pruning, and layer the stem - either by air layering, or pegging to the ground. Spring should see the layered shoot rooted and ready to be removed from the parent.