Augest Gardening Articles

• Wisteria Pruning
  

• How to keep the show going with woody plants

• Late summer colours

Of all the gardening questions I have been asked "How do you prune my Wisteria" must be one of the most often asked…..closely followed by "how do I make it flower"!!

Well the good news is that these questions have virtually the same answer but that assumes that the Wisteria is not a plant grown from seed. Those propagated in this way have to go through an extended period of juvenility before they can bloom. For this reason, I recommend only grafted or layered plants. They may cost a little more but if it means that the flowers come sooner, the colour and size of blooms are superior then paying a little bit more for something that is probably going to outlive you is I reckon money well spent! A Wisteria seedling will probably flower after 7-8 years, some take much longer. But a grafted plant invariably flowers in a much shorter period. This year I was struck by how many of the three year old plants we sell produced flowers here in the nursery.

Position of planting is important. Good drainage and plenty of sun are essential so a south or west facing wall is good. Wisterias also are beautiful climbers for pergolas and to scramble in a natural way into large trees.

So having made your choice, planted your young plant in the right place, what about pruning? Well for the early years there isn't much to do but train and support the strongest shoots that will form the major branch framework. Eventually there will be more side shoots than you need and these need to be pruned back hard now. This summer pruning gives plants a bit of a shock and tips the balance from producing more leaves and shoots into directing its' energies into producing seeds. To do this the plant needs to produce flowers! Many plants under stress (in this case caused by the hard pruning) try to ensure that seed is produced. In this case the buds left on the short secateur-length side shoots are suddenly exposed to extra light and this triggers them to form flower buds. If you have the time, a further shortening of these pruned side shoots in February to stubs that have just two or three buds left is said to help but in my experience it is this drastic summer chop that triggers the flowers.

Wisteria allowed to grow into large trees are best left to their own devices and not pruned. Those trained as small compact trees, such as the one illustrated in my garden, are easily dealt with and like all pruning, I find a very satisfying and rewarding practice.

As to which variety to grow? Well, if you can wait before making your choice, I recommend a visit next spring to a very fine collection of Wisteria at that local bastion of horticultural expertise Cannington College, Bridgwater. There you will find many mature specimens. If you want to get going right away then its' hard to beat a good form of the Chinese Wisteria such as 'Prematura' 'Prolific' or 'Burford'. I have a soft spot for the white varieties and have a very fine Japanese form (floribunda alba) which, although later flowering, looks stunning atop a wall against a dark green woodland background.

Autumn is the best time to plant but, as plants should be grown in pots by nurserymen (beware of some mail order offerings that are bare root seedlings), it is possible to plant all year round with some good aftercare. We always have a good selection in stock.

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Last week I suggested a few easy to grow hardy perennial plants that will perk up our gardens at this time of year. These are quick performers that, by and large, retreat back into the soil in winter. Although slower growing and requiring more space, there are some great trees and shrubs that wait until now to come into the limelight.

I mentioned the Sedum family (Ice Plants) as being sure fire magnets for attracting butterflies and bees but a woody shrub runs a close second. Caryopteris is covered in masses of tiny pale or dark blue (depending on the variety) fluffy flowers and, if planted in full sun out of the wind, will attract insects from far and wide. This is a shrub that is best pruned back to just a few inches above ground level every spring as the best blooms are produced on fresh young shoots.

Oddly enough, blue is a common colour with these late summer flowering shrubs. Blue Hydrangeas will still be putting on a good show but will only flower blue if in an acid soil and of a variety that reacts to this low soil pH. 'Autumn Glory' Hebe is more purple than blue but will be better suited to where space is limited.

Although rather slow growing, the outdoor hardy Hibiscus 'Blue Bird' is worth making room for. These love, but don't demand, heavier clay soils. The showy cup-shaped blooms are not limited to blue with 'Woodbridge' still one of the best pink varieties to plant. Some have bicolour blooms with dark red eyes and either pink or white outsides. Pure white can be found in the variety 'Diane'.

Most Magnolias are spectacular spring flowerers but not all! The great American Southern evergreen ones relish the heat of summer and, whilst they will never grow as big here as those that dominate the front lawn of so many southern mansions, they are dramatic trees. Indeed, if they did grow as big here, there would be very little room for anything else in our relatively small gardens. Fortunately they don't and for many years this spectacular evergreen was restrained by training onto a south or west facing wall and pruned back heavily every year. It was originally thought that they would not thrive and flower away from the protection of these warm walls but, whether it is global warming or just that they are much hardier than first thought, many a fine specimen can be found as a dramatic evergreen tree well away from the protection of any wall. Blooms are spectacularly large and often as big as dinner plates! The fleshy thick petals are cream in colour and are delicately citrus scented.

Abelias may be less spectacular but are perhaps suited to smaller gardens. Most are semi-evergreen and long flowering but a newer variety that impresses me has dramatic golden and red variegated leaves. This variety, Abelia 'Hopleys', lends itself to growing in pots too. It's dainty soft pink trumpet shaped blooms and spectacular foliage make it a real winner in late summer.

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