Tag Archives: gardening with perennials

Tikorangi Notes: underplanting, gardening with perennials and the magnificent nuttalliis

Pretty Rhododendron Yvonne Scott (nuttallii x lindleyi x dalhousiae) with a named clematis but I have lost its name – relevant to the last para on this post and a prettier photo to lead with than the mishmash of a garden bed below 

Not good at all. The addition of roses was a particularly ill-considered decision

I spent a good four or maybe five days taking this unsuccessful garden bed apart. It was first planted about 14 years ago and the original idea was that it continue the theme of the driveway border – mixed shrubs with predominantly hellebores as underplanting. It has never thrived and over the years, its treatment has followed a pattern that many will recognise – random attempts to spark it up that have made it messier and more disjointed.

I lifted everything except the Queen palm (Syagrus romanzoffiana), an attractive Viburnum sargentii ‘Onondaga’ and Camellia minutiflora. The location is too sunny for the hellebores and they were not thriving, so I planted them elsewhere. And I found why the plants at one end had never thrived. I could only get the spade half way in before I hit what might as well be bedrock. It was the old driveway with very heavily compacted road metal. I recalled that Mark had got the nursery staff to plant that bed when it first went in. Now, our nursery staff were whizzybang at speed-potting plants and doing the hard graft of keeping a production nursery going but gardeners, they were not. I am guessing they chiselled holes just large enough to fit the plants in. No wonder so many failed to thrive. There was nowhere for them to get their roots down.

The aim is to have a carpet of harmonious under planting by the end of summer

I took out any larger stones and rocks I could get out, dug the soil and incorporated compost at a rate of a small barrow-load per square metre. There is still not a great depth of soil but what is there should be better and I won’t try growing any more deeper-rooted plants at that end. When it came to choosing what to replant, I fell back on my mixed border philosophy. When there is a mixture of shrubs in the upper layer, it is better to choose some uniformity in the ground cover layer. The opposite is also true: where there is uniformity in the upper layer of shrubs and trees, it is more interesting to use a mixture of plants at the ground level. It may be a sweeping statement (well, it is) to say that only landscapers, non-gardeners and novices go for regimented simplicity of matching upper layer plants and a single choice ground cover – tidy, visually effective in the immediate stage but essentially dull.

A totally reliable stoeksia that is particularly amenable to being divided and transplanted

Given the feature shrubs and palm are interesting in their own right and the presence of assorted seasonal bulbs, I chose to replant at ground level with the reliable, long flowering blue stokesia which thrives with us, a ground-hugging blue campanula and two forms of our native brown carex grass.  The upright form is Carex buchananii , I think, but I am not sure what the fountaining version of it is called. They are to form the carpet. I like the combination of blue and the mid-brown carex. Then I mulched it all. Now all it has to do is to grow.

May 2019

November 2019

It is quite gratifying to see how much the grass garden has grown since I planted it at the end of May. I am hoping that it will have closed up quite a bit by the time autumn comes. There have only been a small number of deaths amongst the plants – all were  Astelia chathamica and fortunately, I have more plants to hand that I can move to the gaps. The advice from colder climates is not to move perennials in winter because they are not growing and the risk is that the roots will rot out over winter. With our mild winters, this advice does not generally apply here but that may be the case with the astelia. The divisions all had roots when they went in but it may be that some did indeed just rot out before they came back into growth in spring.

My main task in this new garden is staying on top of the weeds. Considering it is new ground, there is not a big weed problem at all and I am determined to keep it that way as it gets established. Weeds getting a hold amongst the fibrous roots systems of perennials and grasses can be a maintenance nightmare. It is better by far to keep them out from the start, as far as humanly possible. Because it is all ground that has been freshly dug this year, it is easy to hand pull those pesky weeds that do try and make an appearance.

Eighteen months to fill in seems a quick result

Even more rewarding is to see the caterpillar garden hitting its stride – nicely filled out, floriferous already, weed-free and colour-toned as I want it. It has taken about eighteen months to get it to this stage. Gardening with perennials is very different to gardening with trees and shrubs. As long as you have plenty of divisions and the ground is well-prepared, the plants can rocket away and fill spaces quickly.

Species selection of R. sino nuttallii, singled out for its unusual pink flush

However, no perennial can compete with the sheer magnificence and stature of the nuttallii rhododendrons that flower for us at this time of the year. These are not often commercially available – at least not the sino nuttallii species. You may sometimes find some of the hybrids around that are nuttallii crossed with lindleyi, sometimes with the addition of dalhousiae. If you find ‘White Waves’ on offer in New Zealand, it is proving to be one of the best of the hybrids we grow – reliable and a good survivor as well as very showy indeed. “Mi Amor’ is also available for sale. The hybrids have smaller leaves than the nuttallii species and are not all as strongly scented  but you may just have to take what you can find if you want to try growing these choice rhododendrons.

Rhododendron nuttallii x sino nuttallii – so the Tibetan form crossed with the showier Chinese form

 

 

 

The Chelsea chop comes to New Zealand

Lobelia, phlox, campanula, aster, pensetemon and coreopsis - all candidates for the Chelsea chop here

Lobelia, phlox, campanula, aster, pensetemon and coreopsis – all candidates for the Chelsea chop here

We are fairly dedicated viewers of the long-running series BBC Gardener’s World. Of late it has been on free to air Choice TV (interspersed with huge quantities of advertising) and sometimes it turns up on the Living Channel. There was a programme that screened here last November which demonstrated the technique of the Chelsea chop. I tried it in a small way and will be doing a great deal more of it this coming year.

The Chelsea chop came by its name, apparently, because at the end of the annual Chelsea Flower Show, many surplus plants were returned to nurseries. These plants in full growth, nearing or at their peak, were often cut back hard. Presumably some were plants forced into early growth to peak for the show and that early growth can be leggy. Plants responded with greatly increased vigour and put on extended floral displays with much bushier and more compact shapes.

Thus did the term the Chelsea chop enter the lexicon of English gardening.

Right, I thought. Chelsea is towards the end of May which translates to November in our hemisphere. I headed out with the snips to experiment. It seemed extreme because I was cutting off flower stems which were already well advanced. In some cases, I cut half and left half. I can now report that it works and I will be doing a great deal more of it next spring.

Important points to note are that we are talking about perennials here, not shrubs or bulbs. You need to understand your perennials because it only works on varieties which repeat flower. If you snip the ones which only flower once, such as irises or aquilegias, you won’t get any flowers at all.

I tried it on perennial lobelias, sedums, penstemons and asters.

The unchopped lobelias have shot up their flower spikes to over 1.5 metres and they have promptly fallen over in the welcome rain this week. The plants I Chelsea chopped are only a few days behind in their stage of flowering but have tidy, sturdy stems about 50cm high. They are much better in the garden borders.

Sedum, left to its own devices and falling apart already

Sedum, left to its own devices and falling apart already

Many readers will understand when I complain about the sedums which grow brilliantly from such tidy rosettes at ground level but when they reach a certain point of being top heavy, they fall apart. The Chelsea chopped ones are a more compact and holding together at this stage.

I cut the asters because I didn’t want them to flower until late summer and they were threatening to do it too early. They are just opening now, on lovely bushy mounds of plant, and should take us into autumn.

I see the Telegraph website advice is to do it with Campanula lactiflora (which can get a bit too tall and fall over if you don’t stake it), rudbeckias, echinaceas and heleniums as well. Their writer advises to prune back by a third. Essentially it is a more extreme version of pinching out plants at their early stages to encourage bushier growth.

Perennial gardening is our current learning project here. We have been working on it for a few years now and the more we learn, the more we realise there is to learn. New Zealanders don’t have a great record in perennial or herbaceous gardening. We lean more to bunging them all in together in mixed borders, or working from a very limited palette in large swathes of the same plant.

Sedum, cut back last November and holding itself well. Flowering is unaffected

Sedum, cut back last November and holding itself well. Flowering is unaffected

The mix and match approach to perennials is very English. They just do it so much better than anywhere else we have seen. Underpinning it (at its best) is a wealth of experience in successional flowering and good combinations. It is not just flower colour combinations, it is also compatible growth habits. This may be growing a naturally leggy plant (such as Campanula lactiflora) through a plant that is sturdy enough to support its leaning companion. It is making sure that a big voluptuous plant can’t flop all over a low growing, more retiring specimen. It is getting variations within the foliage as well as the flowers. It is getting the plant shapes right.

And it is not just peak flowering looking its best for three weeks of the year. It is understanding which combinations will take the garden through the season from spring to autumn, so as one finishes, another star takes centre stage. Judicious use of the Chelsea chop can extend the display, staggering flowering through the season.

There is a lot to it. No wonder people opt for mass plantings of the same plant. It is much easier. So too with the cottage garden which does not require the same level of skill. This type of intensive gardening is not to everybody’s taste but we are finding it interesting to learn. To be honest, I had not appreciated the skill that goes into putting in a really good planting of herbaceous material.

I will be doing my best impersonation of a garden hairdresser come this November. I will be out there snip, snip, snippin’ away.

First published in the Waikato Times and reprinted here with their permission.

Reviewing our mixed borders

The Ligularia reniformis were gratifyingly responsive to being dug and divided

The Ligularia reniformis were gratifyingly responsive to being dug and divided

Because I garden extensively, I have a lot of thinking time. Not for me the IPod and little headphones to fill the solitary quietness. I prefer to hear the birds and be aware of all my surroundings while I talk to myself and ponder.

My thinking this week has been coloured by a book I am reading. You will have to wait a little longer for the full discourse on “The Bad Tempered Gardener” by Anne Wareham. I am still digesting the contents but it has certainly focussed my attention on some of my least favourite areas of our garden. I had figured that in one area, the fact that I didn’t enjoy gardening it at all was an indication that all was not well there.

What got me thinking was the oft repeated message in the book that it was better to keep to a more limited plant selection and to shun the bits and bobs effect of one of this and one of that. This particular viewpoint is so much at odds with a great deal that I have written that it has taken some reconciling. I have often bemoaned the boring and limited planting schemes of so many New Zealand gardens and the simple fact is that neither Mark nor I have any interest at all in visiting a garden with a totally restrained use of a very limited number of different plants. Similarly, I have been critical of the ever diminishing range of plants on offer to the home gardener as nurseries continue to refine their production. To us, a garden that is all form and no plant interest is boring. To the author of this book, a garden that is all plant interest and no form is just as bad.

As always, the answer lies somewhere in the middle. And that was what led me to A Revelation. The messy borders and beds I dislike maintaining and sometimes find myself walking past with eyes averted, are frankly messy beds with too many bits and bobs at ground level. The underplanting, in other words. Too often there has been a gap so I have tucked something in to fill the space – and ain’t that the way many of us garden? And all these areas are mixed borders.

The combination of Siberian iris and Bergenia ciliata works very well

The combination of Siberian iris and Bergenia ciliata works very well

Mixed borders are by far the most common method of gardening – planting woody shrubs, maybe trees, and underplanting with herbaceous material and bulbs. I am not a huge fan of this style of gardening, though we have plenty of examples here. They are probably the least successful areas of our garden. But the remedy, I think, lies in revamping that bottom layer of mostly herbaceous material and getting more unity and harmony in managing the combinations.

Not carpet bedding. It is only a short step up the social scale from bedding plants on roundabouts to carpet bedding nepeta (catmint) beneath your roses, or swathes of uninterrupted mondo grass around your topiaried bay trees. It is just as utility and unimaginative, merely in better taste than marigolds.

That is where my thinking, coming from the other end of the spectrum to the author, met up with hers. The magic is in the plant combinations. If you are going to narrow your plant selection, it matters a great deal more which ones you choose and how you put them together.

I am revisiting my intense dislike of mass plantings. I realise now that my out of hand dismissal had much to do with all those Bright Young Landscapers who dominated the garden scene in this country in the decade through to the global financial downturn. Often with big budgets and other people’s gardens, they rejected plantsmanship in favour of form. Lacking any technical knowledge of plants themselves, or indeed any interest in plants beyond their role as soft furnishings, they claimed superior status as they used some of the dullest plants on earth to create gardens which ideally looked the same for twelve months of the year.

The hallmark of good gardens, in my opinion, is the ability to combine both form and detail, which involves thoughtful and original plant combinations. They don’t all have to be wildly unusual plants. One of my successful recent efforts was a cold corner where I used Bergenia ciliata (that is the one with big hairy leaves and pink and white flowers in spring) with deep blue siberian irises. It is unusually restrained for me, but the combination of the narrow upright leaves of the iris and the large but low foliage of the bergenia looks good even without flowers. I hasten to add, I only have about six square metres of this planting. Had I done the entire length of the border the same, it would have been over forty square metres and that I would have found extremely dull.

The same principle of contrast applies to an area where I dug and divided Ligularia reniformis (that is the enormously popular tractor seat ligularia). It was so grateful it romped away and stands large, lush and over a metre tall. With a backdrop of a common plectranthus which has pretty lilac flowers at this time and interplanted with the narrow, upright neomarica, it is simple but pleasing to the eye.

Now my mind is focussed on the messy borders that don’t work. I am pretty sure that if I refine the bottom layer of plantings, that will set off the upper layers. I can’t wait to start.

First up for a revamp

First up for a revamp

First published in the Waikato Times and reprinted here with their permission.

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.

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[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.

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