Hooray for May and the growing abundance of purple blooms! For the budding gardener May provides alliums a plenty and the delicate lilac of the wisteria - a favourite plant for me as it heralds the beginning of early summer and hints at the promise yet to come.

Wisteria is a fabulous plant that can hide a multitude of sins if grown upon a pergola or up an unsightly wall.

In the gardens at Hever we are treated to a fabulous display in late spring and early summer. The white blooms on the walls of the castle are courtesy of Wisteria sinensis ‘Alba’ and we have floribunda ‘Black Dragon’ in the Italian Garden. Wisteria sinensis, is a good species to choose - it looks spectacular as it produces its flowers before its leaves in the spring. It’s also very hardy and grows at an impressive pace.

We have a very productive wisteria on Pergola Walk at Hever which was planted in the first decade of the 1900s, around the time the pergola was erected. Pergola Walk, designed and commissioned by William Waldorf Astor runs for an impressive eighth of a mile from the golden gates beside Half Moon Pond all the way down to the loggia and lake. The wisteria trails approximately halfway along the pergola, climbing clockwise up the struts and sunbathing brazenly upon its roof.

The trunks and stems of this mature wisteria require good sturdy support. If you’re thinking of planting one and have longevity in mind then make sure the support you provide is strong. Wisteria can cause damage to gutters and downspouts, so, if you decide to plant against the wall of your house, make sure you keep an eye on where the tendrils are going!

Wisteria can be reluctant to bloom before it has reached maturity so it’s a good idea to read about the provenance of your wisteria - some species can make you wait up to 20 years for flowers to bloom! You can avoid disappointment by buying a plant that's in bloom or choosing a named cultivar.

Wisterias are generally fast growing and prefer a moist, well-drained soil. As with our wisteria on Pergola Walk, they enjoy full sun and will climb until they reach it. It’s a good idea to water in the drier spells from July to September to ensure you will get blooms the following year.

If you’re thinking of investing in a wisteria this year then go for one that has been grown from a cutting or by grafting - wisteria grown from seed aren’t reliable and tend to take a lot longer to flower. Once the plant is a few years old, a relatively compact, free-flowering form can be achieved by pruning in February and again in August.

I had a quick look at Wiki earlier today and apparently the world's largest known wisteria is in Sierre Madre in California, and stretches for more than one acre and weighs in at 250 tons.

This mammoth shrub was planted in 1894 and is of the ‘Chinese Lavender’ variety. If you haven’t got an acre to spare for a rabid wisteria, then it is possible to choose dwarf varieties like ‘Amethyst Fall’s which you can grow beside a low wall or in a large pot.

This smaller variety has dense clusters of lilac-blue flowers which seemingly drip from the plants twining stems emitting a delicious fragrance that needs to be savoured - so make sure you plant near an entrance or beside a seated area to get the full wisteria experience!