Category Archives: Abbie’s column

Abbie’s newspaper columns

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.

Blue sky gardening rather than feeling blue

Weeds maybe, but pretty on summer roadsides - agapanthus

Weeds maybe, but pretty on summer roadsides – agapanthus

There I was, having decided to write about blue flowers this week, when I opened the latest issue of NZ Gardener and Lynda Hallinan had beaten me to it. But that’s all right. She was mainly looking at annuals with just a few perennials and one shrub.

It is the sight of the blue jacaranda in full flower which makes me fall in love with blue blooms all over again. It is the first thing I see out the window every morning and I sit and drink my early morning tea admiring it and reflecting on how much I love the colour.

Where we live, blue is the dominant colour of the roadside flowers in summer. I know agapanthus is a weed and difficult to eradicate but our verges would be the poorer for its absence. Plants have to be tough in that situation and the agapanthus is a showy survivor. Beacons of summer, here.

The simplicity of chicory

The simplicity of chicory

The wild chicory is pretty as a picture with its soft blue daisies. In the garden we grow blue asters with a similar flower but in long grass, the simplicity of the chicory is more fitting.

We are blue hydrangea territory, being acidic in soils. With regular summer rain and mild, humid conditions, the blocks of blue flowered hydrangeas tend to mean we take this plant for granted. Go to more alkaline territory and they turn pink as readers may have noticed in other areas, but they add to our blue palette here. As we fluff around our garden hydrangeas, pruning each year to tidy them up and promote good flowering, it is interesting to reflect that those roadside wildflowers are never touched yet bloom faithfully. As a general rule, if you don’t prune a hydrangea, you get more flowers but they are smaller.

Impressed by the garden performance of the You-Me hydrangea series

Impressed by the garden performance of the You-Me hydrangea series

When it comes to the garden, those big blue moptop hydrangeas (the macrophyllas) are okay as a backdrop but they lack refinement as garden plants. We have been most impressed with the more delicate appearance of the recent introductions from Japan in the You-Me series. We collected several from hydrangea expert Glyn Church a few years ago and have lost the names but they are all quite similar so I’m not sure that any one is better than the others. Look for them branded under the You-Me group and they carry individual names like “Forever” and “Eternity”. If you can’t find them in your local garden centre, then you can get them on line from Woodleigh Nursery. Be warned, however, that they are apparently not colour stable so if your soils are more alkaline, they won’t be the pretty blues we have here. Presumably they will be pretty pinks instead.

What is it about blue? For me, I think it is that the blue as blue skies are such a mood enhancer. It may have something to do with the dreaded holes in the ozone layer (though I hope it has more to do with our isolation and low population) but we have a clarity and intensity of light in this country that most of us take for granted until we travel overseas.

I have commented before on the fact that we treat green as colour neutral in the garden. All those monochromatic garden schemes are in fact bichromatic because they are one colour plus green.

Nigella damascena - a personal favourite

Nigella damascena – a personal favourite

Blue is not colour neutral as such, but it sits happily in any colour combination. So if your garden bed is hot colours of reds, yellows and oranges, blue will sit in that mix quite happily. In you have gone instead for pretty pastel pinks and whites, blue does not shout when included. Of the primary colours, it is the easiest to blend. It can lift a tightly controlled, colour managed garden out of the blandness that sometimes afflicts them, by adding just a little zing.

I don’t understand why “feeling blue” is a reference to feeling sad. In my books, you can never have too much blue in a garden and lifting one’s eyes to the blue sky above is a celebration of life.

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

The answer, as they say, lies in the soil

What is visible above ground is entirely dependent on what is happening below

What is visible above ground is entirely dependent on what is happening below

A reader took me to task for last week’s column, objecting to my careless use of dirt as a synonym for soil. I would argue that “dirt” is merely the vernacular and in no way demeans the gravitas of soil, but it did get me thinking about the natural growing medium beneath our feet. I also found a wonderful throwaway comment in the same book that gave this week’s gardening quote – The Curious Gardener’s Almanac.

Following on from the old adage of “look after the soil and the soil will look after the plants” was a variation on the theme: “Feed the soil, not the plants”. Yes, I thought. That was a message that spoke to me. We swim against the modern tide and rarely use garden fertiliser here, preferring instead to rely on home-made compost.

Garden soil must be the least sexy and interesting part of gardening for the novice. Yet every single experienced gardener, without exception, will tell you that the state of your garden soil is critical to the end result with the plants. It is just that the plants are a lot more interesting so beginner gardeners start with them. There can be an awful lot of fatalities before they work out that the state of the soil may need some serious attention.

The current craze for no-dig gardening is another issue altogether which I may return to in the future. But whether you opt to plant in the ground or on top of the ground, the growing medium that houses the roots of all your plants is critical.

We are in-ground gardeners here and are lucky to be on free draining, fine, volcanic loam which is one of the easiest natural mediums of all with which to work. Others are nowhere near as lucky.

The aim is to develop friable loam

The aim is to develop friable loam

At the ends of the spectrum are the fine, sandy soils (predominantly in coastal areas) and heavy clay. The former is lacking in humus and does not retain moisture or nutrition. The latter holds too much moisture in wet times but can take on a concrete-like consistency in dry times. Clay lacks aeration, making it difficult for plant roots to function well.

Often new housing subdivisions end up with deeply inhospitable soils. In the past, developers were renowned for removing the top soil and then selling it back later when the home owner wanted to start a garden. I have no idea if that is true but where excavation has been necessary, developers are unlikely to understand the need to set the top soil layer aside in order to replace it in its rightful place on top when the site is finally levelled again. They are more likely to mix it all up so you end up with the sub stratas (often heavy clay) dominating the top layers.

If you are new to gardening and are not at all sure what your soil is like, take up walking around your neighbourhood. If you have neighbours, you are sure to find one out in their garden and most will be glad to give you advice. Soil types can vary widely, though if you are in dairying territory, you are likely to have better soils.

If your soils are less than ideal, set aside the prepackaged or processed fertilisers. They are a short term fix for short term plants but won’t do anything at all for your soil structure.

Sandy soils which dry out very quickly lack humus and sustenance for plants. There are probably very few worms, yet these wrigglers play an important role in mixing up and aerating the soil. You can alter the structure, but it takes work and time. You need to load in the compost, leaf litter, grass clippings, seaweed and any other natural material which will add substance to the soil. Keep at it over time too. It is not a one-off task.

Animal manures should be left to age before you bury them in the soil. They are too strong when they are fresh and can burn plants. You can dig a trench and bury your kitchen scraps directly in to the ground. You are just trying to get as much organic material into the soil and then the worms will start arriving along with all the other natural microbial action and insect life of healthy soils.

Clay soils also suffer from a lack of worms but they are not lacking in nutrients as a rule. Basically, the aim is to break up the clay to allow for better drainage, increased worm activity and aeration. Adding gypsum is one strategy. Bringing in very fine gravel or sharp river sand is reputed to help but you are likely to need several centimetres of it to make any difference and it will need to be dug through the clay. Otherwise, do the same as for sandy soils and bring in mountains of humus. Build up your layers on top. The worms will arrive and start to do some of the work for you.

You are trying to speed up a natural process where top soil builds up closest to the surface, giving you friable and fertile conditions in which to grow plants.

None of this is rocket science. It just takes time, effort and a strong back if you are starting with impoverished soil conditions. You often have to take the longer term view in gardening.

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

Cover the ground

Happy and easy care perennial impatiens

Happy and easy care perennial impatiens

I mentioned last week about my mother’s gardening mantra being ground cover which focussed my mind on the case for ground cover plants. Surprisingly, this preoccupation is a relatively recent phenomenon.

Back in the 1950s and 1960s ground cover plants hardly featured. It was all about trees and shrubs with little under planting. Now it is often regarded as a hallmark of good gardening to have no dirt showing at all – except in the vegetable garden. Mostly it is about packing the garden with layers of plants, each lower layer masking the stems and trunks of the taller ones while down the bottom is some low but strong growing ground hugger.

There is good sense to not having exposed dirt in a garden. Keeping it covered stops dirt splash in the rain, wind blown top soil in the wind and erosion in torrential downpours. A good thick layer of something, be it plant or mulch, can cut down on the germination of weed seeds lurking in the soil because it reduces the amount of sunshine and light that most need. It is also a great deal more attractive than the liverwort that colonises uncultivated ground in shaded areas.

There are ground covers and there are G-R-O-U-N-D C-O-V-E-R-S. Some modest little ones never get ideas above their station and just gently colonise an area, spreading in a quiet and acceptable manner. In this class, I would put the unassuming but pretty little scuttelaria which we have in both white and blue or the obliging corylopis and a number of the ajugas.

Then there are the rampant ones which, given even a hint of an invitation, will spread at an alarming rate. I once bought a punnet of such a plant which looked promising. I have long since lost its name but it had pretty white cup flowers and good green, fine foliage. That punnet held six plugs, each measuring about 2.5cm across. Within one season, each of those plugs measured a metre across. I have never seen anything spread so alarmingly. It took me two years to get rid of it entirely, all the time muttering that the people who propagated that plant for sale should be lined up and shot. For the same reason, I have eradicated the Orangeberry plant (Rubus pentalobus) and rampant violets. I don’t want lemon balm either. It stages a takeover bid, choking everything in its way. And the ornamental tradescantia is pushing its luck.

Zephyr beside the Acanthus mollis

Zephyr beside the Acanthus mollis

We are extremely cautious about the triffids too. These are the large growing perennials which spread and choke out much in their path, seeding their way through the garden. Acanthus mollis or bears’ breeches springs to mind as a good example. One can be striking but don’t turn your back on it and allow for the fact that every one needs at least a metre and a half of space. Too many and your garden looks as if it is full of cheapie plants as bulk fillers. We call it the ABG syndrome after we heard somebody’s garden described as being a case of Another Bloody Gunnera. Those particular triffids are now on the banned list in this country, as far as I know – the enormous rhubarb plants.

Endless plant lists without photos make dull reading, but I will offer up a very short list of recommended, well behaved ground cover plants which have proven their worth here and should be readily available. In shade areas, it is hard to go past hostas, farfugiums and ligularias but also the francoas (sonchifolia and ramosa- the Chilean bridal wreath flowers) and phlomis. We have a wonderful swathe of old fashioned perennial impatiens (busy lizzies) which have kept on keeping on for decades in frost free woodland conditions. They flower for 10 months of the year and require next to no attention.

The mottled foliage of pulmonaria (with the unromantic common name of lungwort)

The mottled foliage of pulmonaria (with the unromantic common name of lungwort)

In sunnier conditions, the sedums work well, as do coreopsis, smaller growing campanulas, phlox, asters – there is an endless list of possibilities. I am less keen on the widely used catmint (nepeta) which I regard as too strong a grower and essentially boring. I much prefer the mottled foliage and pretty flowers of the pulmonaria which fill a similar niche.

For those who find using perennials offputting, the permanence of ground cover shrubs sometimes appeals, especially flowering shrubs. We used to sell pretty little weeping camellias (Sweet Emily Kate and Quintessence) which, if not trained upright, would become ground cover. And somebody has apparently released a “ground cover” michelia. I know this because I have been asked for it but have not seen it yet.

But, ground cover shrubs in a mixed planting? I don’t recommend them. We tried Sweet Emily Kate and very soon discovered the drawbacks. There is nowhere for the spent flowers to drop to so all that happens is that slushy blooms and other garden debris sits on top of the plant, needing frequent picking over by hand.

If you want ground cover, keep to perennials or seasonal bulbs and annuals is my advice. If you want to reduce maintenance, mulch with something anonymous like compost or bark chip instead and bypass the ground cover altogether.

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

Cicely’s gardens

My mother and sister at the start of another of her gardens

My mother and sister at the start of another of her gardens

I have been thinking of my late mother, Cicely Denz, this week and realised I have never paid tribute to the fact that I, as well as Mark, grew up in lovely gardens. The difference is the plural – Mark grew up in the one garden that is now our home at Tikorangi. I grew up in multiple gardens, mostly around Dunedin.

She was a fine garden maker, my mother, though the gardens were distinctly clonal. She worked from the same plant list of favourites and she never stuck around long enough to see them mature. I am sure it would have been different had my father lived longer and she had her lifelong love next to her in body and not just memory. She would have put down roots and may well have earned a place in the modern garden history of this country.

Instead for a woman of her generation, intelligent but under educated with no recognised career, lacking a man at her side when solo parents were almost unknown, leading a distinctly precarious financial existence and lacking the usual anchors in life, my mother turned her gardening into her public face and her claim to status.

She was always a gardener. Her first was an acre in size. When my father was demobbed post WW2, he went to work at Porton Down in Salisbury. As that place was a military scientific research facility, this may well have contributed to his premature demise (think nerve gas research, organophosphates and other agricultural chemicals). With the shortage of housing in bombed Britain, they relocated two military huts and my mother built her first garden around them. Despite extensive reading of the major English garden writers, she never deviated from the romantic English country cottage style of gardening of that era.

By the time I was born, my parents decided to return to New Zealand with the four children in search of the traditional NZ family life and employment opportunities meant Dunedin. That English style of gardening translated well to Dunedin which may never get as cold as most of the UK but has similarly low sunshine hours, never gets hot and is characterised by a soft light unknown to most of us north of there.

Every garden had Prunus Kanzan

Every garden had Prunus Kanzan

She was always renowned for her proper English primroses. They will grow here in more northerly climes but they hardly flower whereas my childhood was spent with vases of them in season. Along with violets, hellebores and London Pride. Roses were always of the old fashioned variety, not a vulgar hybrid tea in sight. And herbaceous paeonies, big clumps of these spring delights. We all grew up knowing the name of Paeonia mlokosewitschii – she was a demon for botanical names. Every garden had at least one Prunus Kanzan (in pink) and one Prunus Tai Haku (in white).

The paeony with the impossible name

The paeony with the impossible name

Lawnmowers were not her friend. She attempted to pressgang any passing young male into using the push mower on grass which tended to be overgrown. At one stage, she decided that a brand new motor mower might do the trick. This required site visits from the poor young salesman, whom she probably reduced to tears with her complete inability to start the engine and her tendency to blame the machine. The shop took the mower back.

In due course, Cicely gave up on all lawns. She figured that it cost money to maintain a lawn (it does) and she would rather have gravel paths and garden.

Not only did she not have lawns, there was a total lack of hard landscaping. Good gardener she may have been and certainly she had no fear of hard work, but she lacked any home handywoman skills and she rarely had sufficient money to pay for someone else to come and install anything like fencing or paving. Garden ornaments were completely absent. Mind you, this was in the days before it became fashionable to adorn your garden like an overstuffed display cabinet.

I quipped many years ago that all she needed to keep her happy were five plants, a spade and a wheelbarrow. She could then move the plants like chess, as she was wont to do. But she was a garden maker at heart. The joy for her lay in breaking in a piece of ground and planting it up, garnering much admiration from passersby and neighbours. She had little interest in maintaining the garden once established so soon became bored, finding some compelling reason to move. I kid you not. In my lifetime, I can recall about ten gardens she made. There may have been more.

Her mantra was ground cover. She firmly believed that if you plant ground cover densely, it suppresses the weeds. Well, no. She didn’t like weeding and ground cover plants mask the weed infestations, rather than suppressing them. It also makes weeding more difficult because the weeds and plants become deeply intertwined. Her style of gardening was hugely labour intensive and generally involved lifting all the ground cover perennials once a year and dividing them so the weeds did at least get dealt to annually. She spent pretty much every single day in her garden.

Cicely’s style of gardening was transient. These gardens lacked the bones to carry them through the decades. There was a lack of good long term trees and a lack of structure or form. I doubt that any survive now. She never went back to look. But for the few years of their glory, they were a delight and a fine example of that particular garden style.

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