“The only constant is change,” so said a Greek philosopher 2,500 years ago. It still stands true today, in gardens as much as the rest of life. The seasons of course naturally bring by turn that cycle of bud break, flower, fruiting and leaf fall. But we as gardeners play our part too with our constant intervention. Through time, planting, pruning and generally tending to our plots, changes all.

Even the most celebrated, seemingly static elements of historic gardens evolve. Constant, perhaps in our eyes, but growing and changing almost imperceptibly down through the centuries.

Levens’ low box hedges have long outlined, in rich green, the garden’s intricate patterns. Enduring, though not fixed, they have been carefully trimmed each season for generations. They are lifted, lowered and reset every 50 years, maintaining through time their creator’s original vision for the parterre. Due for renewal again, two years ago this symbol of Levens’ heritage faced a fresh challenge. The new, virulent fungal disease, ‘Box Blight’ had struck.

Unknown a decade ago, this predatory pathogen has rattled through the great gardens of Europe, laying low great swathes of box, a previously unassailable green hedger. Known as ‘The Black Death,’ for the rapidity of infection, the tell tale darkening of the foliage, and the certainty of a speedy demise. This particular plant plague almost always proves terminal.

Fungicides prove no match to this natural killer. Within three hours the spores can germinate and penetrate plant tissue, and within three days it can be all over. It affects all forms of Box, but the low hedging sort has the thinnest leaf, so is the first to go. We were devastated when we first saw it, but in gardening we learn to be philosophical. There are no such things as problems, only opportunities...

Every generation faces its own challenges, and here at Levens it will be finding a worthy successor to Box for our low hedging. Front runners at present are the small leaved evergreens ‘Ilex crenata’ and ‘Teucrium x lucidrys’ though we have quite a few more on our list of possibles.

Watch TV gardener Carol Klein help us replace the first short stretch tomorrow night. (Gardener’s World, BBC2 Friday 8.30pm). That’s 2 metres done, 2 kilometres to go!

As the man said, “The only constant is change...”

Chris Crowder is head gardener at Levens Hall

chris.crowder@me.com

Jobs to do this week:

Now is the best time to get turf in, on and established. Use it to repair damaged edges and worn areas, and more extensively to lay down new lawns.

Plant out shallots and onion from sets. These are a quick and easy way to grow onions, but watch out for birds tugging them out of the ground until they get their roots down.

Start cannas and dahlias into growth - moist fresh compost and warmth are the triggers. Take short basal cuttings of the dahlias if you want more.