Hostas with the mostest

They are big, beautiful and their splendid spade-shaped leaves will brighten up the darkest and dampest patch in any garden, says Monty Don

MY hostas are getting bigger and bigger. For many people it seems that any healthy growth of a hosta is a victory in the fight against the ravenous depredations of the local slug and snail population, but mine have never really been attacked in any meaningful way. No, mine are not outgrowing slug and snail appetites but simply coming i nto maturity.

I have a number of different hostas but most are chosen from a small group of extra-large leafed varieties that take a few years to reach their full display potential. In particular, the glaucous ‘Snowden’ and H seiboldii and the much yellower ‘Sum And Substance’ all grow beautifully lush and — critically — all have nice thick, tough leaves. This thickness, rather than the actual size of each leaf, is what makes them less desirable for a hungry snail that is ideally looking for softer tissue to digest.

Hostas are very hardy and will grow almost anywhere, although they are happiest in damp shade. The dampness and the shade can vary from deep, dark bog to the dappled light of a woodland edge but there is a good rule of thumb: the less shade a hosta has, the damper the soil should be. Certainly, to get the very best from them you should plant them in rich, damp soil, make sure they spend at least half the day in shade and mulch them well with garden compost or manure every spring. And as with every plant, the happier and healthier a hosta is, the less likely it is to be attacked.

I know that many people grow their hostas in containers — and I have one large variegated one (the variety long forgotten) that is very happy in its terracotta pot. But you have to enrich the potting compost as much as possible — I would recommend half pure garden compost to half peat-free potting compost — and water it every day in hot weather and weekly between October and March.

A really good soak in the middle of winter — when the foliage has completely died back — does them the world of good.

I grow my hostas by the edge of our pond, mingled in with primulas and the shuttlecock fern Matteuccia, its upright funnel of lacy leaves providing the perfect foil for the fat sprawl of the spade-shaped hosta leaves.

I also have a particularly blue-leafed variety called ‘Halcyon’ edging a path in the Jewel Garden. These dozen or so plants grow completely happily in normal border soil and over the past ten years have never been so much as nibbled.

Hostas used to be grown for their flowers, and I don’t think we really make enough of this aspect of the plant. The range of flower colour extends from almost pure white such as H plantaginea, to deep purple such as H tardiflora, although most are a shade of lavender.

The flowers are followed by flat seeds that are black if fertile, but pale if sterile.

But growing them from seed is much slower and less practical than propagating them by division.

The easiest way to do this is to dig them up, place them on the surface of the soil and chop each plant into pieces with a sharp spade or bread knife if you want to be more precise. As long as each section has a visible flowering bud attached to a section of root then it will make a new plant that will regrow vigorously, although it will take a year or two to grow foliage and flowers of the maturity it had attained before you split it.

The time to split is ideally April, but as the leaves die back, autumn is fine too.