Now’s the time to service your hardy perennials

Phormium is spreading.
Phormium is spreading.

This is a good time to be introducing, relocating or propagating hardy perennial plants.

You can now buy that long-admired ornamental tree and have it standing to attention in the border long before Christmas. Alternatively, dig up and move a fruit bush that has outstayed its welcome in a particular spot.

A polythene sheet saves lifting.

A polythene sheet saves lifting.

Better still, take a spade to the invasive herbaceous perennial that has become too big for its boots, then gain lots of new plants when it’s divided up.

All this because many plants have entered a state of dormancy for winter.

Quite often you can see what needs to be done and even start the activity full of vigour, only to discover that you’ve underestimated the bulk of a particular plant.

If it can be levered out of the hole after loosening the roots with a spade, ease it onto a sheet of tough polythene and drag it to the new planting spot rather than attempt to lift a dead weight.

A sedum clump to divide.

A sedum clump to divide.

I planted a variegated New Zealand flax (Phormium tenax) in a border by the driveway five years ago, and those long spear-like leaves have been so impressive that we failed to note how quickly it was spreading.

The time has arrived for action and there is no easy solution. In keeping with most herbaceous plants, all vigour is on the periphery and that is the starting point with a spade.

The outer growths can be dug up with roots attached and planted elsewhere, given to friends or composted.

Well-established clumps of pampas grass present a similar problem which is exacerbated by the glass-like property of the leaves. Wear gloves when tugging at them to avoid laceration. Gardeners of yore who had little time for health and safety, and no intention of attempting to control this plant by digging, practiced an alternative method that I do not recommend.

Sedum after division.

Sedum after division.

This was demonstrated by my gardening mentor one winter morning.

We walked to a huge pampas in the clearing of a woodland setting and he thrashed it with a rake as a warning to any animal life present. Rolling up a newspaper, he then set alight to it and touched the plant base before retreating rapidly. It burst into flame, a worrying sight, then only a charred stump remained. It shot into growth when spring arrived. Do NOT try this!

By comparison, controlling herbaceous perennials that have invasive tendencies is straight forward. Dig up large clumps of rudbeckia, astrantia, anaphalis, et al now.

Lay them on the soil surface and divide them up. Discard old central growth, retaining the youthful outer roots and stems. Sometimes they can be teased apart by gloved hands, or by putting two forks back to back in the centre to gain leverage. If the plant has a seemingly impenetrable mass I simply slice it apart with a spade.