Tag Archives: digging and dividing perennials

In the garden this fortnight: June 21, 2012

A fortnightly series first published in the Weekend Gardener and reproduced here with their permission.

Before - too much mondo grass, not to mention superfluous hostas and Ligularia reniformis needing attention

Before – too much mondo grass, not to mention superfluous hostas and Ligularia reniformis needing attention

There are times, I admit, when the advice I give as a garden writer is from the do-as-I-say school. Digging and dividing perennials is an example – a recommended activity but not as urgent as other tasks here so rarely gets done. I am reformed, inspired by the dramatic response of plants which I lifted, divided and replanted into well dug soils last year. They romped away. I am working my way through the garden borders, lifting pretty much every perennial (but leaving Helleborus orientalis – the most common hellebore. It doesn’t appreciate being disturbed). As some have been left for well over a decade, it is a major task and takes some physical effort. It also gives the opportunity to clean up the perennial plantings to achieve a more cohesive look. Years of plugging gaps had meant that some were pretty hodge-podge in the selection of plants.

I have carted away two barrowloads of green mondo grass from just one smallish border – too much mondo. A drift of yellow polyanthus will give winter colour, interplanted with bluebells for early spring contrast. The variegated Soloman Seal (Polygonatum multiflorum var.) will give spring and summer detail, all held together by the evergreen tractor seat ligularia (L. reniformis) and the green mondo grass (Ophiopogon japonicus) – but in moderation. All of this is in the lee of a large mandarin tree, which gives wonderful orange winter colour with its abundant fruit. The fun part of gardening is deciding on different combinations for different areas but after the hard work, patience is needed before it all starts growing again.

And after - it needs to grow but it is very tidy

And after – it needs to grow but it is very tidy

TOP TASKS
1) Limit the mondo grass – both the black and green forms. It seems to have quietly spread into too many areas where it is not needed at all.
2) Get a layer of compost mulch onto the borders where I have been working. The compost will feed the plants while stopping dirt splash in rain. It is a fiddly job because it needs to be placed around in each plant by hand.
3) With only two months until spring here, the pressure is on to get winter projects done. This includes my reconstruction of the rose garden. It will make a major mess so once started, it is a case of needing to persevere until it is done. I have not been game to start yet but will run out of time unless I get moving.

Outdoor classroom – rejuvenating tired perennial patches

[1] Many of us have areas of garden which look like this – tired and dull. Although this patch has been kept weed free, mulched and deadheaded, it is many years since it has been actively gardened. There is no alternative to a bit of hard digging.

tired and dull

[2] Dig out all the plants. You can see how heavily compacted the soil has become over many years. It was originally rotary hoed which made it light and fluffy but that was a long time ago.

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Placing the plants on a mat beside where you are working will reduce the mess.

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[3] Dig to at least the depth of the spade and dig again, breaking up any clods of dirt. This incorporates air into the soil and encourages worm activity. Rake the area to an even surface for replanting.

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[4] Different plants divide in different ways so look closely at the plants. The pulmonaria at the top of the photo will pull apart easily to three separate pieces, all with roots and growing crowns. The phlomis at the bottom of the photo could be cut into many plants but I will take this to just two strong plants, reducing each to only one or two growing points.

OC-4-13-5-2011

[5] If you have dug well, you can replant using just a trowel. Try and avoid planting in rows – staggered drifts look better. I want a quick result so am planting at about 15cm spacings. Take the oldest leaves off the little plant, leaving fresh new growth tips. Remember that the soil is fluffed up and the next rains will compact it a little, so don’t plant at too shallow a depth. Only plant the strongest and the best divisions.

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[6] We give a light feed of an all purpose fertiliser – in this case our locally produced Bioboost – and then mulch. This patch was dug, divided and replanted about three weeks ago and has a mulch of wood chip from our shredder. It should be well established and look lush and vigorous in spring time.

OC-6-13-5-2011

A step by step guide by Abbie and Mark Jury first published in the Taranaki Daily News and reproduced here with permission.