Category Archives: Abbie’s column

Abbie’s newspaper columns

The Chelsea Chop

Jerusalem artichokes

The Chelsea chop is a time-honoured British gardening technique. Its name is related to the Chelsea Flower Show towards the end of May each year; that is the recommended time for gardeners to head out with their secateurs, snips or handy flax cutter in order to sever a third to half of the fresh season’s growth on various plants.

Why this drastic action, you may ask. Cutting off half the growth at the peak of its spring spurt does two things; it delays flowering but, more importantly, it makes the plant more compact and sturdy with its second growth.

We do a bit of it. Where we know we will have problems with plants needing a whole lot of staking to prevent them flopping all over the place, we try and get around to cut them down in their prime. Being on the other side of the world, we do not do this at the time of the Chelsea Flower Show. November is our time and, in our mild conditions with rampant plant growth, I aim for early November so a few weeks earlier.

I think it may be a form of Miscanthus sinensis but it has a broader leaf and much more vigorous growth than ‘Morning Light’. A thug, even.

I started by experimenting on chopping back a large growing miscanthus that, in a single season, could put on an overwhelming amount of foliage and generate such weight and volume that it all just fell apart well before the end of the season. Cutting it back very hard indeed in winter when the foliage is all dying off (it is deciduous) and then again in  November works a treat and means it can stay in the garden.

Will the Jerusalem artichokes respond better if Chelsea chopped next spring?
“No! Not the Chelsea chop!” cried this artichoke as it threw itself to the ground in dismay during heavy rain and wind this past week.

There is a bit of an open verdict on the Jerusalem artichokes as an ornamental plant. Put in last year, they have bolted to over 3 metres high. Canberra daughter looked at them and said she Chelsea chops hers but she is going to dig them out anyway and replace with the tall Echinacea laciniata. Not enough flowers, she said. I waited for mine to flower and she is right – foliage to flower ratio is waaaay too high. I saw yesterday that one plant has given up the ghost in moderately severe weather. I shall keep one patch to experiment with Chelsea chopping it next spring but it had better put on a better display of blooms or it will go the way of its compatriots which are destined to be removed this week.

Sedums are a lot more attractive when they don’t fall apart and flop in mid flower

The two plants we regularly Chelsea chop are sedums and perennial lobelias. Unless we have just dug and divided the sedums, they grow rapidly and then fall apart which spoils the effect entirely. And I don’t want to be digging and dividing the sedums every year. Chelsea chopping them means they produce shorter, stouter stems which can hold the weighty blooms up.

I don’t seem to have photographs of the perennial lobelias on file so I had to pick the last three stems of the season for those of you who are not sure what a perennial lobelia looks like

Similarly lobelias grow rapidly and put out tall flowers without enough strength in the stem to hold them aloft. I am not going to stake lobelias, I can tell you that much. Chelsea chopping them is working, as is deadheading them to reduce their spread.

You do have to know which plants respond to this treatment. If I am uncertain, I will chop half the patch only, leaving the rest to grow as per normal and then I try and remember to keep checking through the season. Chopping only some of the plants is also a way of extending flowering season: the untouched flowering stems will open as usual whereas the chopped plants will come into bloom anything up to 4 to 6 weeks later.

Mostly it is done on perennials but only some of them. There are lists on line – echinacea (though I am uncertain why one might wish to Chelsea chop echinaceas), asters, phlox, solidago, campanulas and helenium come to mind. Never try it on bulbs, perennials that only flower once like irises, and most flowering shrubs will just shrug their shoulders and not flower at all this year and sometimes next. Timing is important – you need to do it when the plant is at its most energetic and in full growth and the plant needs to have vigour.

I don’t want to Chelsea chop every perennial; I have quite enough to do in the garden without adding unnecessary tasks. I just try and get around to doing it on plants that I know will cause problems later in the season if I don’t.

“You’ve got mail”

Two interactions this week brought me unexpected pleasure.

The first was an email from Michael in Portland and I was so touched by his words I asked his permission to share it here. I post it without comment except to say that the ‘Dark Tulip’ Magnolia he refers to is of course our Magnolia ‘Black Tulip’.

Magnolia Black Tulip ihere

Hello! 

This is a bit of story, but I want to express how grateful I am for your Dark Tulip Magnolia. 

I grew up in Mississippi, which is in the southern part of the United States and southern magnolia is the state flower. When I was about five years old my father took me to a garden center where we bought a small southern magnolia. He told me that was “my” tree. I loved that tree and it became a symbol of my childhood and my relationship with my dad. I’m in my late 30’s now and I live in Oregon, which is +2,000 miles from Mississippi. I rarely go back to Mississippi, but when I do I always drive by that house to sit at look at that giant magnolia from my car. My dad died unexpectedly almost two years ago and magnolias are still very much connected to him in my mind. 

I’ve always wanted a magnolia of my own, but I’ve been living in apartments my entire adult life. This winter, I finally moved into a house with a (small) yard. I knew I wanted to plant a magnolia even if I had to grow it in a pot (for now). I went to a nursery here in Portland and the moment I saw your Dark Tulip Magnolia, my heart jumped! The blossoms stopped me in my tracks. The flowers immediately sent me back to so many childhood memories, to memories of my father planting our tree. But yet this magnolia is… an evolution of something… the unbelievably deep and soul moving burgundy is stunning! It’s hard to express, but your Dark Tulip Magnolia has become a symbol of growth after loss, of moving forward, of change. It’s deeply poignant to me. 

I purchased my first tree of my adult life: your Dark Tulip Magnolia. I have it in a very large container, which I know is not ideal, but it is the best I can do for a few years. I am determined to learn everything I can and do my best to help it thrive. This living art you’ve created has played a role in healing my heart and in my life story. It is the most beautiful tree I have ever seen. 

Michael’s plant

I know the Dark Tulip Magnolia has been around for years, but it is new to me and I’ve been reading everything I can find about how to keep it healthy. I want you to know that your work has created profound meaning in my life. I am so grateful for the years of work you’ve put into creating such beautiful trees. 

Thank you for the beauty you’ve contributed to the world and to my life. 

Michael

Magnolia Black Tulip – the first magnolia of Mark’s breeding that he named and released

It is always rewarding when people derive pleasure from plants bred here by Mark and Felix before him. When one touches somebody in a deep emotional, almost spiritual way, that is next level altogether.

The rare delight of a hand written postcard

The second  treat this week was when the mailbox delivered up the rare specimen of a handwritten postcard. In a week when NZ Post announced the demise of posties, to be replaced by courier drivers, a handwritten card seemed especially poignant. It was a letter of appreciation from a reader of this site. The bit that made me laugh out loud was: “But I really had to say a big thankyou for ‘sad beige’!!!! So funny (and sad!)”

I read that bit out loud to Zach as he came into work that morning and he snorted in delight. It was he who gifted me ‘sad beige’ as in here , here, and here.

Appreciative comments from readers are always treasured but readers who share my sense of humour are gold.

Back in the days when people still bought and read newspapers, I used to get more feedback on the garden pages I wrote from 1997 through to 2015. I just looked up those dates and I am stunned I kept it up for 18 years. Mark used to call the incoming mail my ‘fan mail’. I kept the special ones and I shall add the postcard and the email to that file. I am a bit sorry I can’t store the phone calls I used to receive from elderly gents wanting to discuss growing potatoes. This was in the days of landlines and phone books, you understand, a time when there were quite a few elderly gentlemen wanting to discuss potatoes. Never having grown a potato in my life, I would hand those calls over to Mark who was far better equipped on the topic. They were oddly charming, in a niche sort of way.

Early autumn in the Wild North Garden

Seamless transitions – doing away with garden edgings

Beth Chatto’s dry garden in the UK was a revelation for us and, to this day, we see it as a major influence in the whole shift of direction with the New Perennials or New Naturalism movement that is more commonly attributed to Piet Oudolf.

Beth Chatto’s dry garden

Beth Chatto was planting on an old riverbed in an extremely low rainfall area and she wanted a garden that did not rely on any irrigation at all. Clearly this bears no relationship to our conditions. We never irrigate because we don’t have to; we never suffer from low rainfall. But it is the absence of garden edgings I want to draw attention to.

I don’t for one minute think that they have to do as much maintenance on their perennials in these testing conditions in Beth Chatto’s garden. We would be digging through that mulch and bringing up the soil from below all year round.

Garden edgings are basically about containing the garden and giving definition. To do away with them altogether completely changes the look and makes it far more natural in appearance – albeit while not being natural at all. I really like the look and debated about it when we were putting in the Court Garden but decided not to for practical reasons.

The Chatto garden again

It came back to mind recently, firstly with the visit of Australian, Michael McCoy and then looking at some of Penny Zino’s photographs of her summer gardens in North Canterbury. I don’t have permission to use their photos here  but you can find them both on Facebook where they post photos able to be viewed by anyone or go to their own sites – https://www.flaxmeregarden.co.nz/gallery for Penny Zino and https://thegardenist.com.au/ for Michael McCoy. I am not an Instagram user but Michael is active on that forum too as @michaelmccoyongardens. If you browse their photos, you will find examples of these seamless transitions – paths meandering through plantings in the Chatto style and very charming it is, to my eyes at least.

We used a fine, cream coloured grit that compacts well throughout the summer gardens

All of us appear to have chosen the same path surface in fine, cream grit and that, in itself, gives definition and lightness. Our grit is 50% crushed limestone and 50% crushed shell, bought from a local supplier of gravels and rocks. Beth Chatto used a mulch around the plants that is the same colour as the path grit but pebble-sized so it looks the same at first glance but it is in fact easier to rake to the side when digging is required. I didn’t notice that at the time but it is clear in my photo records. Not having seen their gardens except in photos, I don’t know whether Zino and McCoy have also carpeted their entire area in the same as mulch or whether they just allow the paths to peter out into leaf litter and soil as it goes further into the plantings.

I chose to go with an edging in the Court Garden for reasons that were entirely related to ease of maintenance but we chose an informal edge in lengths of pine bark from on site

It made me reflect on why it is not a practical option for us and why I decided against it. There are several reasons – climate, the presence of large trees, plant selection and maintenance. I think it is a dry garden technique and we are anything but. If the path surface extends through the garden as mulch, it looks best if there isn’t a whole lot of leaf litter and debris on the surface. With the number of large trees we have and being in a windy climate, we have falling leaves and debris all year round. Keeping the cream-coloured paths clear is a big enough job for us, without having to leaf rake or blow all the garden surface too.

Added to that, in our soft climate, we have rampant growth and managing perennials means constant cutting back, digging and dividing, restricting and deadheading to prevent too many self-sown seedlings. Plant selection becomes critical if you want that seamless look because every time you dig a plant, you disturb the mulch and make a mess. When set in cream grit mulch, it would be easier from the start to choose plants that grow from a central stem – lavender, euphorbias, roses, and salvias come to mind. Plants that form rosettes or spread beneath the ground – like perennial lobelias, alstromerias, asters, echinaceas, rudbeckias – all need regular attention to restrict spread or to keep healthy by dividing. I want to grow all these, too.

It is why we favour composted wood chip mulch. It is easy to top up at the end, cheap to use and, when weathered and composted, it just adds natural humus to the soil. It is best to source a woodchip that isn’t too coarse. Some mulching machines make a big chunky chip which takes much longer to weather and is not attractive to my eyes. Our friendly, local arborist (he lives up our road) provides a good grade of chip which soon becomes anonymous in appearance.  When I cut back or deadhead, I often snip the pieces to smaller sizes and leave them in situ to break down naturally. If I had decorative mulch, I couldn’t do that. 

Ralph tones in particularly well with the grassland

Our compromise was to go for that seamless look and meandering paths in the area we now loosely refer to as ‘the grassland’. It is a transitional filler space, primarily using just two native brown grasses, Carex buchananii and Carex coman’s ‘Bronze’ along with a fair swag of interlopers (‘volunteers’ as we call plants that just arrive of their own accord), residual survivors from its earlier uses and bulbs I have added for seasonal interest. So, a limited plant palette overall and most of the maintenance is pulling out seedlings (particularly of the carex) and a bit of occasional grooming of the grasses. It is not carpeted in cream grit but in woodchip – paths and mulch. It is a lower-key look that lacks the contrast and lightness given by the cream grit but it is a long-term, sustainable option in our conditions.

Seamless in woodchip

Seedling variation

I found the range of different seedlings in the self-sown dwarf cosmos this year interesting and thought some readers may, too. Last year, we planted seedlings of Cosmos ‘Bright Lights Mix’ (from King’s Seeds) for late summer colour in the rockery. They performed well, stayed compact in growth and provided vibrant splashes of colour at an otherwise drab time of year for that garden. Our rockery is predominantly smaller bulbs and it peaks twice a year in autumn and then in spring. Summer conditions are tough when it dries out, the soil heats up and there is little life in the soil but the cosmos didn’t turn a hair.

Because the seedlings are reasonably easy to recognise, they didn’t get weeded out but came up, bushed out and flowered in abundance over recent weeks. It is much easier if they can self-seed and not need to be raised from scratch in a seed tray and then planted out again. These cosmos are not subtle; they are perhaps reminiscent of marigolds (tagetes) but a simpler flower with clean colours so I prefer them. Cheerful, they are.

Mark’s and my early evening sitting spot is on the front porch, looking across the rockery and the variation of growth habit and flower colour caught my attention. These second generation seedlings were showing more variation than the original plants from last year. Most of the plants have remained pretty bushy and compact, which is what we want in the rockery even though we are usually sniffy about bedding plants, commonly seen in floral clocks and on traffic roundabouts. But some of the plants have reverted to the taller, more open, willowy growth that I associate with other cosmos varieties I have grown in the past.

It was the variation in colour, size and flower form that led me to picking a selection. The colour range is from a clear lemon yellow, through a gamut of golden hues to orange and then deepening to reds, but not a pure red as we know it. Some are fully single with just one row of petals, some have two rows of petals and the ones with three rows of petals are the fullest flowers on the plants. Bees love them but it wasn’t until I looked up the supplier’s website that I found out they are, allegedly, not only edible for humans but also tasty. “Flowers are edible with a sweet nectar flavour, try them in salads as garnishes or float in summer cocktails.” I have not used them as a culinary garnish, but I am sure this may be handy to know.

Most plants in the wild reproduce by seed and Nature is full of seedling variation. My cosmos are just a small example of Nature in action. When you buy packets of seed, you are trusting the supplier to have made selections from the best and most desirable seeding parents. When you save your own seed, always select from the best plant – be it garlic, tomatoes, annuals or anything else. Don’t make the mistake of saving seed from the smallest plant or fruit that you don’t want to eat. Careful seedling selection down the years is what gave us sweet corn instead of tough old maize, chunky orange carrots instead of very thin purple ones and a host of other plants. 

I may yet pull out the leggy cosmos to give more chance for the more compact ones to be the seeders but the bees will have cross-pollinated them already and any seedlings may still throw taller plants. In removing the leggy ones, I am just bettering the odds of a compact future generation.

Zach diffidently gave me a few seedlings of a named cosmos he had raised from seed. “I don’t think you will like it,” he said. “Murky colours.” He knows I prefer clean colours in the garden whereas he likes colour blends. I guess you could describe the flowers as subtle; to my eyes, they are more insipid that subtle. I won’t be sad if these ones fail to seed down.

I once photographed these tall, white cosmos in an Auckland garden. En masse, they were absolutely lovely. I even bought a packet of seed in anticipation of something similar in our blue and white Wave Garden but I am not very good with starting from seed – that is Mark’s territory. From memory, my seed was patchy in the extreme and the only plants that grew to flowering size were not pure white but candy pink and white which was not what I wanted at all. Clearly that seed had been collected from a plant that had cross pollinated with a neighbouring pink. Maybe I could try again.

Summer gardening

Gladioli bulbs

Here is a sight to strike terror in many gardeners. Those are gladiolus bulbs, in this case a yellow flowered hybrid. I knew it was a ‘vigorous’ grower, as the euphemism goes. I just didn’t realise quite how enthusiastic it was about increasing.

No wonder Gladiolus daleni is escaping from gardens into the wild

Some aspects of gardening are somewhat akin to micro-surgery. Removing many of those bulblets that have detached from the parent is one such activity. There is not much alternative to gently working through the soil and picking them out one by one. I had noticed Gladiolus dalenii had the same habit and I haven’t started on that patch yet. The only other plants I can think of that we grow here with a similar bulblet production are the ixias and alliums. They should come with a warning that control may require precision gardening.

When I thought about it, I share the opinion of Crocosmia ‘Lucifer’ – foliage ratio too high, flowering season too short, rampant growth and a bad seed-setter

When I wrote recently about plants that may be good but I don’t want them everywhere,  it clearly struck a chord with a number of readers. My current bête noire is mondo grass – ophiopogon – and that means picking out every fallen seed as well all the runners. Susan, who leads the volunteers at the Te Henui cemetery, tells me she is reviewing the plant material they use and making lists of plants that she intends to get rid of and those that she wants to restrict heavily. They want the place looking colourful, vibrant and pretty all year but, while the overall area is very large, much of it is viewed close-up and they don’t have the labour to carry out the highly detailed plant care that is possible in a domestic garden. As a result, they need to use plants which will still look good – or at least not a mess – when their flowering is over. I could understand that she had the large pink watsonias on her list to get rid of; I was initially surprised that lychnis and Crocosmia ‘Lucifer’ are also for the chop. Fortunately, Susan keeps good records and I have asked her if I can use her plant list as she refines it. I think it will be a good resource for perennials that under-perform or fail to pass over gracefully in our climate. That will take time to eventuate but may be a lot more useful to New Zealand gardeners than overseas plant lists.

Yet again, I have been surprised by how much time and effort I put in over summer to keep our new perennial gardens looking good. Our experience in the past included extensive use of perennials and bulbs in shade gardens but not in full sun where perennials G R O W, spread and often flop over. In our conditions, we spend a lot of time deadheading to restrict the rampant spread and a fair amount of time staking and tying followed by de-staking. You can get rid of this by being a great deal more selective about which plants you use but many of the ones I enjoy the most need this extra attention. It can all become a bit utilitarian if plants are to be selected primarily on being low maintenance.

If you are going for a lower maintenance garden, stick to trees and shrubs, avoid bulbs and only use perennials in shady areas is my advice. Shade gardening is generally lower maintenance because the plants don’t grow as rampantly in lower light levels. We are into high-interest gardening rather than low-maintenance gardening.

It is always a bit harder working out what to do in high summer. It is the right time to dig bulbs as just a few are starting into growth but totally the wrong time to move woody trees and shrubs. I find I can move perennials as long as I can get water to the site (we don’t irrigate here) and replant them well with plenty of compost and water and then mulch. They are currently in full growth so can re-establish quickly if steps are taken to mitigate the summer dry and heat. I am chipping my way through some of the lesser borders we have in the garden.

Preternaturally tidy at this moment in time

Like many, if not most, homes in this country, we have awkward, narrow, very dry borders around the house defined by a concrete path. I find the two I have just done preternaturally tidy. This one is predominantly home to two different forms of veltheimia and I haven’t done anything with it but weed and tidy for maybe 15 years. This time, I dug everything bar the rosemary plants and two lapageria vines, saturated the poor, spent soil and enriched it with compost before replanting. As I walk past that abnormal tidiness several times a day, it occurs to me that this is what too many people judge to be ‘good gardening’. No, what is good gardening is when all the plants bed in and how it looks firstly this spring and then in 3, 5 or 8 years’ time, maybe longer.

Commonly referred to here as ‘the veltheimia border’ but I reworked it because I realised the veltheimias were in the process of going back, not thriving.

It was very gratifying in late spring to have a garden designer friend from Auckland call in with a companion he wanted to see the place. What he singled out was how well the plants were bedded in. Not tidiness, but the creation of plant communities that are established and look as though they belong together over time.

Orchids happily bedded in, seen in spring.

So much of gardening is taking the longer view rather than instant gratification. And tidiness can be over-rated.