Tag Archives: Stipa gigantea

The grass report

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I feel sufficiently confident to give an interim report on the grasses I have used in the new Court Garden although it will take another few years before I can give a definitive verdict. These are bigger growing grasses because we had the space and I wanted an immersive effect that wraps around when we walk through the area.

The site is the hottest area in our garden but, being lowered, it can also be frosty in winter. Cold air flows down to lower levels to settle. The ground is typical free-draining, Taranaki volcanic soils that do not become water-logged and never dry out entirely. We haven’t added any fertiliser and once planted, we never water. The area is mulched with wood chip.

Chionochloa rubra – commonly known as red tussock but this form is only brownish red in winter

Chionochloa rubra – NZ native so evergreen. It takes first prize for graceful form because it fountains out from a narrow base and that form makes it a real star in the winter garden. Its flowering is relatively insignificant but I don’t have to groom the plants to remove dead sections. We started with just one plant and I kept dividing it, which it does easily. I have never lost a plant. It needs space to be able to appreciate the graceful form and the best plants are now 120cm high with a spread up to 2 metres.

Chionochloa flavicans, sometimes sold as ‘miniature toetoe’ though it is a different family

Chionochloa flavicans – also a native, sometimes referred to as ‘miniature toetoe’, so evergreen. At its best in spring but holds its showy flowers right through until autumn. Rabbit fodder when young. Has the reputation of ‘whiffing off’ unpredictably and it certainly doesn’t appreciate being crowded by other plants. Again, we started with a single plant and kept dividing. I have overplanted it so will lift the lot shortly and split the plants, replanting fewer and at wider spacings. I am hoping that by dividing, it will stimulate more growth and delay any inclination to ‘whiff off’. Plants are now about 75cm high and up to 140cm wide.

Anemanthele lessoniana or NZ wind grass, sometimes gossamer grass (you can see the ethereal flowers in pink tones) in the borders before I moved it over to the Court Garden
Anemanthele after moving – it turns golden under stress and it was still hot weather when I moved these plants but I expect them to recover

Anemanthele lessoniana – another native – so evergreen – with a vase shaped habit of growth and more colour variation in the foliage. Lovely in bloom with a cloud of fine flower heads. I had this in the twin borders but the plants were getting too large so I have now moved them to the Court Garden. When stressed (and my plants have often been stressed as I have lifted and divided them to increase the number from the original three), it turns an attractive gold but I will need to groom the foliage to remove dead thatch when the plants make fresh growth. It has reached about 90cm high and up to 140cm wide.

The tall plumes are the austroderia – NZ toetoe and a better choice than Argentinian pampas

Austroderia fulvida – toetoe so another evergreen native.  Very large growing and too early for me to comment on its longer term performance. I bought three small plants through Trade Me and they have already reached 1.7m high and 2.4 metres wide.

Stipa gigantea I have referenced countless times. It, too, is evergreen in our conditions and I  give it the occasional groom (by hand or with a leaf rake) to remove dead foliage. Excluding the tall flower spikes, it is about 80cm high and 160 cm wide as it matures. It divides and increases easily so just start with a single plant but you do need a certain critical mass to have sufficient to share with the sparrows. We found the pesky birds stripped the blooms in the first season and the whole reason for growing this grass is for its showy, long-lived flower spikes so that was disappointing. This year we have had plenty to share with the birds. The foliage has a glaucous tint which is a contrast.

Calamagrostis ‘Karl Foerster’ to the left with the plumes still looking good after four months

Calamagrostis ‘Karl Foerster‘ – I have written about this before. It is such a strong grower, spreading at an alarming speed, that I reduced it down to just six plants which I am hoping I can keep in check by root pruning on an annual basis. By root pruning, I mean getting a very sharp spade and cutting back the size of the clump without digging it all out. That way, I can get the spreading fresh growth off it. This works because it makes its new growths on the outside of the clump. It is evergreen in our climate but the foliage looks pretty scruffy by the end of season. I am pretty sure I cut it back hard last winter so the spring growth was all fresh and lush. It is one of the first grasses to flower in spring and those lovely plumes hold all summer and into autumn. It is all about the plumes because the foliage and form are nothing remarkable.

That is what I think is ‘Overdam’ in the front right, Stipa gigantea behind

Calamagrostis ‘Overdam‘. At least, I think it is Overdam. It was given to me. It is strong growing too, but not as threatening as Karl. It has the same lovely plumes but the bonus of clean, variegated foliage which stays looking fresh through the season, somewhat like a lower growing variegated miscanthus, though it spreads sideways rather than up. It will likely need root pruning, too.

Miscanthus is a lovely grass from spring onwards but the glow of those white plumes in the low winter sun is nothing short of amazing

Miscanthus sinensis ‘Morning Light’. Look, we started with one plant in the garden years ago that just sat, grew annually and fell apart because it needed dividing. As soon as I started dividing it (done variously with a sharp spade, an old handsaw or a small axe), it responded by growing with huge enthusiasm. I overplanted badly and need to take out at least half of the plants but as it is all about the plumes in late autumn and early winter when they glow white in the low sun angles, I will wait. The plants are around 1.7 to 1.8 metres high with flower spikes on top of that so it is very tall. If it is divided often enough, it will stay together – falling apart from the middle is a sign it needs dividing. It is fully deciduous, fine leaved and variegated. Mark is sure that the old foliage has potential for thatching but he has yet to test this theory. This is the only grass that I have spotted seeding down so far but the seedlings are easy to pull out when small.

Miscanthus ‘Morning Light’ on the right, giant miscanthus on the left

Miscanthus whatever whatever – may be just a larger growing form of sinensis with a wider leaf but it should be called Miscanthus giganteus variegatus. The leaves are wider and with a most attractive, clean variegation but the vigour and size is daunting. We ended up digging out three massive plants because I couldn’t hold them together and, as they fell apart, they blocked the path entirely. This is a triffid of a grass. Gardening friend, Susan, suggested that maybe the way forward is to do the Chelsea chop on them – cut them back to ground after the first big flush. I think she is right and I will be cutting them back to ground level about mid November. The second flush of growth should be more compact and shorter. If I can’t keep them under control this way, they will have to go. The plants are too big for me to lift alone and I don’t want to commit to plants that need lifting and dividing annually.

Just too big – they grew even larger and floppier after I took this photo

Lomandra We had a named variety in the garden but I found a better option to replace it with. I rate lomandra as one of the world’s more boring plants and I suggest you leave lomandras to supermarket carparks and roading roundabouts. We have more interesting and attractive native grasses without having to resort to this utility Aussie in NZ gardens.   

Here endeth the interim grass report. Except to say that I am moving and dividing some now because we still have at least six to eight weeks of the growing season left before temperatures drop and growth slows or stops over winter. That said, I have done this in winter and we can get away with it but it is not recommended in less benign conditions where the plants may just sit and decompose in sodden, cold soils.

The Court Garden after its second summer

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August 2018

I am turning my attention back to refining the new Court Garden. How did we manage before digital cameras? They make it so easy to track change. This was where we started with a blank canvas.

August 2019

A year later and I had done most of the planting and the steps were in place. If you look carefully, you may see some little spots of yellow. I drifted many dwarf narcissi through to add early spring interest. This winter will be my last chance to locate them and remove them before they are forever swamped in the grasslands.

October 2020

This is how it looked when we opened for the garden festival last spring, when we had completed the paths. It was the first viewing by members of the public and most visitors loved it.

March 2021

This is the same view, four months later. The growth has been well in excess of what we expected. This is the result of planting into fresh ground although the soils would not have been particularly fertile after being under nursery weedmat for three decades. We have not fertilised anything. Nor did I use compost to enrich the soil. We did, however, cultivate the ground before planting and mulch afterwards. While planting, I squished a gazillion grass grubs that I unearthed as I went.

Chionochloa rubra

Despite my best effort to get the spacings right as I planted. the mistakes are now clear, mostly because I underestimated how large the plants would get. You can see from the markings on the path, how far out the grass stems are sweeping. I am fine with a bit of softening overhang but I also want to be able to walk through without getting wet legs. I need to move the right hand chionochloa back half a metre. Fine tuning, I call it.

Stipa gigantea and ox-eye daisy at the beginning of November

Again, thanks to digital photography, it is easy to track plant combinations through the seasons. I have been surprised that some have held for a good four months. This is just a simple combination of Stipa gigantea (golden oat grass) and ox-eye daisies as it looked when we opened the garden at the beginning of November.

Stipa gigantea and oxeye daisies in mid December

The same view in December. Aren’t those simple daisies simply glorious? As this mass display passed over, I cut them back to the rosettes at ground level.

This is the same spot in February. The daisies are having a second flush and i think if I get my timings right, it may be possible to get a third flush each year. The stipa has also held onto its sterile flowers and I did not expect these to hold for over four months.

Stipa gigantea and Verbena bonariensis in mid December

Back in mid December, I was delighted by the chance combination of a Verbena bonariensis that chose to seed in this spot by Stipa gigantea. I even took a short video of the gentle movement which was everything I aimed for in this garden but my tech skills let me down sometimes and I can’t work out how to upload it to this platform.

Same plants in late February

This is the same scene, two and a half months later. Still pretty, albeit past its fresh flush.

NZ toetoe and Chionochloa flavicans at the start of November

Who still declares that our native plants are boring? Mark said we must have our native toetoe in what is essentially a grass garden. I bought three plants on TradeMe (our equivalent of Ebay) and from memory, I think they are Austroderia fulvida. We have five species native to this country. The smaller plants are Chionochloa flavida, often sold as ‘dwarf toetoe’ although they are a different plant family.

Four months on

Four months later, the flower plumes are still holding, albeit a little tired as we go into autumn. This is not unreasonable on their part.

I think I am ready to give an interim report card on the key plants used in this garden but that will have to wait for another post. It will take another few years before I feel confident to recommend based on longer term performance but some trends are already clear. Pretty much all the plants used are readily available in this country.

The ongoing quest for perfection

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Auratum lily time

Some people like to plant a garden once and leave it. But some of us plant, look, think, weigh up what we have and then decide on action. I am not referring to minor tweaking and culling a few superfluous plants, more akin to major rejigs. I have two in mind, or maybe three. Always there is that quest for something close to perfection even while we know perfection in a garden that is growing will generally be ‘on the day’ only.

The lily border – wonderful but it could be better still

It is auratum lily time and the lily border is magnificent. But it could be better. I planted it in the winter of 2017 so this is its fourth summer. There are a couple of gaps that I thought I needed to fill; I have plenty of lilies I can relocate. But I have looked again and again and decided that it is time to dig the whole thing and replant it – but not until the lilies are going dormant in late autumn. When I first planted it, I put in large bulbs at about 15cm spacings – from the edges of the bulbs not the centres. When planted fairly deeply and spaced, the stems are strong enough to hold themselves up, even when topped by massive blooms. I do not want to have to stake these lilies. There are hundreds of them. Some areas are now so dense with offshoots already of flowering size that they are leaning on their neighbours and not standing upright. When they get too dense, the glory of individual blooms gets lost. It is time to lift the bulbs, cultivate the soil and respace them for next season, discarding the small offshoots. That’ll keep me busy for a week in autumn; there are about 30 metres of lily border.

Our NZ grass, Anemanthele lessoniana looking lovely with echinaceas but it is getting too large for its allocated space

In the herbaceous borders, I have been looking at the Anemanthele lessoniana with some concern. It is a native grass and one of our prettier ones with its orange tones in the foliage and light, feathery flowers with a hint of burgundy. But it festoons as it matures, rather than standing upright and the plants are now taking up a space with a diameter of at least 120cm and swamping their neighbours. It is too big for the borders. I shall relocate the plants into the grassy Court Garden and give them the space they want but it will leave some big gaps behind. I am wondering whether our native Poa anceps will make an acceptable substitute.

Miscanthus ‘Morning Light’ is an absolute star in late autumn and early winter – this was late afternoon on June 6, 2020

And I am spending a lot of time looking at the Court Garden. Just in its second year, I can see mistakes I have made. There are Too Many Miscanthus. M. ‘Morning Light’ is a wonderful grass and generally well behaved, a magical autumn mainstay, but I have badly overplanted them. For longer term management, I need to cull up to half of them to give the remaining plants room to star. We only ever started with one plant of it but boy, does it respond to being dug and divided.

Probably Miscanthus sinensis ‘Variegata’ is proving altogether too vigorous here

I am looking in askance at the giant, variegated miscanthus (it may be Miscanthus sinensis ‘Variegatus’ or Japanese Silver Grass) that a friend gave me. Last year, I managed to keep the plants upright simply by tying a circle of jute string around each plant. They are too big for that this year, in just their second year. I don’t want to be digging such huge plants every second year in order to keep them manageable so I may reduce it down to just one or two specimens and weigh up their long term viability. Does their showiness outweigh the heft and effort needed?

Stipa gigantea still starring after a full three months in flower in the middle ground. The plant at the front is Elegia capensis

What a star Stipa gigantea has been this year. It is all about the flower heads – golden oat grass – and because it is sterile, the flowers have stayed and stayed. After three months, they are still looking terrific. But, I can see I still have them planted too closely, despite culling half of them after last summer. As it matures, the plants can be anything up to a metre and half across and they look best standing in their own space. I need to take out a few more and centre the remaining ones so they don’t overflow onto the paths. It is all about having a critical mass with this stipa, so there are enough flowers to share with the marauding sparrows. They stripped them bare last season but this year they have flowered in abundance, with no evident decline in sparrow numbers. We clearly achieved some sort of balance of critical mass.

Our native Chionochloa flavicans also still flowering after 3 months but I am unsure how gracefully the plants will age

I have an open verdict still on whether Chionochloa flavicans will last the distance with us. It has the reputation of ‘whiffing off’ – dying out in patches – and it is too early to tell yet. At least I know I can use the anemanthele to replace it if I need to. Chionochloa rubra remains splendid but its time to star is in winter when it is the dominant form. In summer, it is less obvious amongst showier grasses.

It is going to take me ten years to come up with a reliable recommended plant list for this style of gardening but it is a lot of fun getting there. And I am fine with using two dominant exotic grasses (the stipa and miscanthus) when almost all the other grasses are natives. We are not native purists here, we like to mix and match but it is also satisfying to use our indigenous plants as equals in a garden setting.  

As I have said before, digging and dividing is way easier if you do a little often because the ground stays friable, making the digging part much easier. If you don’t want to have to dig and divide, plant trees and shrubs, not perennials.  

Miscanthus to the left and to the right – rather too much of it and they appear to be wanting to meet in the middle

Stipa gigantea

Stipa gigantea towering against the sky

When we made our treks across the world to look at summer gardens, there were three plants that were standout performers we were keen to try here – Stipa gigantea, thalictrum and veronicastrum. Oh, and the giant blue-purple alliums but we are not going to pay the big dollars per bulb they command here. The reason they are so common in English and European gardens is because they can buy the bulbs very cheaply from Dutch growers.

We have a pink thalictrum that is doing fairly well, though it has only achieved waist-high altitude and does not look as though it is going to get much beyond that. The sole veronicastrum – the only success after three attempts with the finest seed Mark has had to deal with (he had to get the magnifying glass out to check that he wasn’t just sowing dust) – is growing slowly and seems to be a plant for the long haul rather than a quick result. But the Stipa gigantea….

A friend in Christchurch sent me a few divisions. I have no idea how long it has been in NZ or who brought it in but it is not widely available commercially. That may just be a matter of time and demand. The few divisions grew, and grew and grew until we had many. I started with them in the perennial borders but after the first two years, realised they were going to be too large there so moved them into the new Court Garden where the focus is on big grasses. I knew I was overplanting them for quick effect 18 months ago so I removed over half of them last autumn to give the remaining plants space to stand alone. Each plant needs well over a metre of area.

I like the combination of Stipa gigantea with the ox-eye daisy

The foliage is blueish-green in colour and evergreen, forming a soft fountaining mound about knee-high. But the long-lived, towering, golden flower spikes are the reason to grow it and give it the common name of ‘golden oats’. Last year was something of a disappointment because the sparrows stripped the flowers. Apparently, we can out-sparrow the Brits who introduced that little bird to this country. If we were not going to get the flowers, I wasn’t sure I would persist with the plants.

What a difference a year makes. This season, they are magnificent – a major feature in the new Court Garden. It remains to be seen how long they hold with our bird population but I can live with that because they make a big visual statement in late spring before the miscanthus flower. The ethereal golden heads towering above are so light, they appear to dance against the sky.

I also like the stipa with the dark foliaged phormium coming into flower

As far as we can make out, Stipa gigantea (syn Celtica gigantea) is sterile here, which is helpful. We should be able to confirm this later this season. It is also evergreen. A member of the poa family of grasses, it comes from southern Europe. Given its vigorous growth, it is a good thing it is shallow rooted so easy to lift and divide, often falling apart into divisions in the process. A visitor to the garden told me she was trying to buy one but there was a waiting list and each plant was priced at $40 which made me gulp. I briefly caught myself thinking that I could have easily potted up 40 of them sold them at $20 each during our recent garden festival. But we are over selling plants; we do not want to go back there again.

If you really want to have it in your garden, you could contact Janica at Woodleigh Nursery. I see they are saying sold out at this stage but she tells me she has more which will be ready in autumn. She doesn’t price them at $40 either. You only need one plant and a bit of patience. Within two years, you will have all you need. Just give it plenty of space to star.

The other stipa we grow is Stipa tenuissima (syn Nassella tenuissima) which is very lovely and fluffy but comes with a warning. It seeds down so is on the Weedbusters list though not banned, as far as I know. Avoid it if you are anywhere near native bush or indeed farmland. We don’t need more weed pests invading pastoral land. We are keeping it because it is not a problem in a controlled garden situation and does not seed so badly that we have found it to be a pest.

Fluffy mounds of Stipa tenuissima shining in the light with yellow Phlomis russeliana and Iris sibirica ‘Blue Moon’
Plenty of stipa flowers to share with the sparrows this year. Mark says it is the pollen they are after.

Seven days from the winter solstice – Tikorangi this week

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The white form of Dahlia imperialis

The last tree dahlia of the season is in bloom. Dahlia imperialis alba plena is the towering giant of them all, way up in the sky, not blooming until well into winter so particularly vulnerable to frosts and winter gales. I took this photo yesterday to show those in other climates the intensity of winter light that we get here on sunny days. It is different to those who garden where the winter sun hangs lower in the sky. We are not tropical; I don’t want to mislead. It is almost mid-winter and can be quite chilly. However, it is a lot less depressing to the spirits when you live somewhere with this clarity of bright light, even on the shortest days of the year.

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Miscanthus ‘Morning Light’ shimmering in the late afternoon light

IMG_7040We are now well into what Piet Oudolf refers to as the ‘fifth season’ and the new Court Garden brings me much pleasure, especially in the late afternoon when the sun is dropping lower and shines through the miscanthus grasses. I have used a lot of miscanthus running through the garden in waves and the plumes shine in the light and wave gently in any breeze.

IMG_7031IMG_7039I have finally found a place where this large yellow salvia can grow with sufficient space and it is a late autumn – early winter highlight. We have never had a name on this variety so if any readers can identify it for me, I would be grateful. It stands a good two metres tall so it is a large plant to accommodate. *** Now identified as Salvia madrensis, thanks readers.

Tips and techniques for the week:

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Stipa gigantea after a major thinning exercise

  • I took a before photo of this block of Stipa gigantea in the new Court Garden but I appear to have deleted it when I was filing photos. It looked fine at the end of its first year but I knew it wouldn’t stay looking fine and it was already too congested to allow the plants to fountain out and show their natural form. Last week, I took out well over half the plants and gave them away. I did have to lift some of the remaining plants to centre them to their own space but I am much happier with it now so it was worth the effort. I haven’t grown this stipa before and hadn’t realised how much space each plant needs. I am hoping this can now be left alone for a few years at least. It has a white field daisy growing between which I have learned I can get two, maybe three successive flowerings from spring to autumn if I cut it back to the base rosette at the right time.

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    Layering up the prunings at the back, more or less out of sight

  • Out of the ‘I thought it would be a straightforward job that would only take a day and a half at the most but actually took four full days and still isn’t quite finished’ school of thought, I spent this week clearing the wilderness of boundary plantings that separate the caterpillar garden from the boundary with the neighbours’ wool shed and yards. People with big gardens will understand that you have areas which get planted and then mostly left to their own devices. It is one of those jobs you finally tackle when preparing to open the garden to the public again. Nobody will notice I have done it, but they may well have noticed had I not. Over the years, it had become largely impenetrable with self-sown camellias, layered hydrangeas, native seedlings, especially kawakawa and various mounds of vegetation where I had emptied the wheelbarrow of prunings that I didn’t want in the compost heap. It amazes me how far I can get with a sharp pruning saw. Because there was so much of it, I dragged all the debris to the back and layered it by the boundary fence. At some points, it is quite a bit higher than in this photo. It can gently rot down there, adding humus and carbon to the soil and is a lot lighter on labour than carting it all away to compost and mulch. It is a technique we are using quite extensively now and is a tidy, unobtrusive way of dealing with excessive amounts of garden waste. That said, it is a big garden technique, rather than one for small town gardens.

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    On track to be an undulating, curvy hedge like a moving caterpillar

  • I have started a major clipping round on the hedges in what we call the Caterpillar Garden. The hedge is Camellia microphylla, already nearing the end of its flowering season. The plants were pretty neglected -raised from seed and cuttings many years ago and then left to kick around the old nursery until we were ready to use them. We planted them two years ago and the hedges, laid out in the shape of the basket fungus, are still a bit patchy. Mark’s plan is to clip these hedges into mounded, free-form shapes like an undulating caterpillar in the style we associate strongly with UK designer, Tom Stuart Smith. I am doing the first clip this season and have told Mark it is his job to come through and do the final clip of the top to get the mounding shapes he wants.

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    The straight-edged, hard clipped approach

    Most of our clipped hedges here are very straight sided with the top meeting at right angles. Lloyd does them with a string line to keep the lines straight and the hedges a uniform width. He has a good eye for these things. But after spending a fair number of hours clipping and shaping the caterpillar hedge, I can tell you that it is a great deal easier and more pleasurable to work with a more organic shape and form than that military regimentation of the sharper-edged hedges. Informality is much more forgiving than formality.