Tag Archives: Iris sibirica

Thugs in the garden

I am surprised by how strongly Iris sibirica grows in well cutivated soils and full sun. I have moved the discoloured Xeronema callistemon behind the iris to the right to a more protected position 

Thugs. Not trugs.

We are cautious here. We do not want to unleash plants that threaten to become weeds and therefore become maintenance nightmares. Some plants that set seed rather too freely (like Orlaya grandiflora, Verbena bonariensis and the perennial forget-me-not, Myosotis scorpioides) fall into this category, but they are easy to pull out if they are seeding in the wrong places. Other plants are far more difficult because they wriggle their roots below ground to entwine anything in their way – not unlike couch grass but considerably more decorative. The pretty, blue Salvia uliginosa and Japanese anemones are examples. These are the plants that we are really cautious about placing and controlling.

And then there are the thugs that stand four square and strong and will swamp anything in their way. Thugs need space of their own. Preferably permanent space because some of those thugs can get too large to handle easily in a short space of time. Learning to garden with sunny perennials is teaching me quite a bit about thugs.

Chionochloa rubra, not a thug but seen to best advantage when allowed to stand in its own space

When I planted up the new Court Garden a few weeks ago, I removed such thugs from the herbaceous borders to relocate in the bigger space of the new garden. They are all good plants but way too strong for the congeniality of an herbaceous border. Calamagrostris ‘Karl Foerster’, Elegia capensis and the large growing salvias were the main thugs that I had used extensively. I also relocated all the Chionochloa rubra, not because it is a thug but because it needed more space to allow it to star in its graceful glory. And Stipa gigantea because it was underperforming in the herbaceous borders and I thought it might be better en masse in its own space.

Raiding the borders left some big gaps, and indeed some large holes. No problem, I thought. I had additional top soil to fill the holes and plenty of plant material to fill the spaces and it seemed a good opportunity to tweak a few areas in the borders which I felt were a bit messy – more messy-matrix than dramatic swathes of plants. I figured all I had to do was to consolidate the areas where I had tried to fill in spaces with additional material. A bit of fine-tuning.

I am sure most gardeners will understand that situation where what we think will be a relatively small project escalates into a major operation. This is one of that ilk. For I found the second tier thugs. These plants have only been in two and a half years and for the first two years, I was simply delighted at the quick result achieved in these borders started from scratch. Gardening with sunny perennials was a completely new experience and so rewarding. Yes, well….

Phlomis russeliana to the left, Elegia capensis to the right with Lomandra ‘Tanika’ in the middle

I am now looking in askance at some of the plant selections. Great plants, but they are going to take a bit more work to keep them that way than I had anticipated because, boy, are they strong growers in this situation. Phlomis russeliana – Turkish sage – with its attractive, tiered yellow flower spikes, has quietly flowered away in our woodland without problems for decades. Moved into full sun and well cultivated soil, it has formed massive underground root systems and overgrown tops in a very short space of time. Iris sibirica – wow. Admittedly, I planted large chunks of it in the first place rather than separating the rhizomes and in springtime, it is simply glorious – so much so that I wanted to add new varieties and colours. Hmmm. All that foliage flops over in autumn, smothering nearby plants and it has to be cut back eventually because it doesn’t even pull off easily. I thought it would be a good time to dig and divide them. It took all my strength to get these plants out of the ground and I ended up with mountains of them. I replanted them as individual rhizomes and mulched with compost. In replanting the same area, I ended up scrapping at least two thirds of them as surplus. And each patch of maybe three or four square metres takes about a day and half to do. I have done four blocks, I have two left to do and I got rid of the seventh block entirely. That is a lot of labour input and time to just one plant type.

And the lomandras. These are tidy, Australian evergreen grasses. We only have two different ones and probably started with a single specimen of each because Mark never buys the same plant in multiples. They kicked around the old nursery area for years, unloved, uncared for, waiting for someone to find them a forever home. That should be a clue as to how tough they are.

The compact dark green lomandra (with freshly divided phlomis to the left). It will be a named clone; it is just that we lost the name

The compact, forest green variety (name has been lost in the mists of time) is very good. And very well behaved. The very dark green colour contrasts well with everything, really. I wouldn’t mind it growing a little taller in this situation – it is only knee high – but it is very tidy. Not a wow sort of plant but excellent in the chorus line of back up vocals.

Too much Lomandra ‘Tanika’

The other one we have is Lomandra ‘Tanika’ which is widely marketed in this country. It is larger growing, sort of anonymous mid-green and what is called a reliable performer. It is one of those bullet-proof plants where you start, as we did, with one, put it in good conditions and next thing you know, you have eleventy thousand of it if you want to divide it. Enough to fill a traffic island or a motorway siding, even. It looks attractive in form for the first couple of years but if you don’t lift and divide it, it threatens to become an overgrown, overblown thug.

The autumn hues of our native Anemanthele lessoniana – also evergreen

I can’t get too excited about the lomandras. While they can be tidy plants, they lack the flower power of showier grasses and they are bit, well, utility. Space fillers. Evergreen and they stay looking the same all year round, which, I admit, some people see as a desirable trait. I am scaling back ‘Tanika’ – composting about 80% of it. It has another two years to win me over but at this stage, I think I would prefer to replace it with our native Anemanthele lessoniana which fills a similar niche but with more foliar interest and lower maintenance requirements.

What I thought would take maybe four or five days’ work – filling the gaps in the herbaceous borders created by my earlier raid – has turned into several weeks. I am quite happy doing this because it is an active learning exercise but I don’t think I want to be doing it as routine maintenance.

The lesson is that there is no substitute for trialling plants in situ and making some major calls when it comes to swapping some selections out for others.  It is why other people’s plant lists are a guide, not a manual, especially if they are overseas recommendations. There is fine line between plants that are sufficiently strong growing to hold their own in herbaceous plantings and plants that are too strong to grow in happy congeniality.

Oh, and give plant thugs the space they need or don’t use them at all. Otherwise they will swamp out other plants of a more refined disposition.

At least the Iris sibirica star in spring, even if they are going to take ongoing work to keep them from smothering their neighbours

Not just from Siberia – the sibirican irises

“I think I prefer the sibiricans now to the bearded irises. Much easier care.” So spake a friend who will, for unrelated reasons, always be known as Cemetery Sue here, as we stood looking at my swathes of Iris sibirica in the new borders. In the second year since planting, their display has been fantastic.

I only had three different varieties and they are just one of those good performing, utility plants that I took for granted before. Sue has since brought me a fourth one sourced from the inimitable Bill Robinson (yes, he and Anne are still gardening and growing plants in Tikitere, near Rotorua). Now I wouldn’t mind a few more.

Probably a species selection, rather than a controlled hybrid

Iris sibirica, or the Siberian iris, is very hardy, undemanding – so low maintenance – and fully deciduous which means that it emerges afresh each spring. I had assumed it came from Siberia, and it does grow there but its natural distribution is from northern and central Europe right across to Central Asia (which includes Siberia). In the wild, it is a damp woodland plant, preferring full sun to part shade. Presumably, woodlands in that part of the world are largely deciduous. The received wisdom here has always been that they grow well in heavy soils and are ideal beside ponds and waterways, though they do not grow IN the water but BESIDE it. In Taranaki open gardens, they are usually combined with the bright yellow Primula helodoxa because both grow in similar conditions and flower at the same time, conveniently at the peak garden visitor period.

Caesar’s Brother, of course

I wasn’t sure how they would go en masse in my new sunny borders which don’t have particularly heavy soils, though we get spring and summer rains during their growing season. The answer is that they are sensational, growing larger and stronger than I anticipated in the freshly cultivated soil. The erect foliage is between waist and chest height and the flowers held above that. They have taken my breath away. Even the white and yellow form with tissue paper thin petals (it may or may not be ‘White Swirl’ or ‘Snow Queen’) which I had thought a little insipid where I had it planted previously, was terrific in early spring. We have the dark ‘Caesar’s Brother’ (who doesn’t?) but it was the other blue that is the real showstopper with its much larger flower, longer season and free flowering ways. I wondered if I could put a name on it and that took me down a rabbit hole on the internet. I had no idea there was so much passion for the sibiricans.

A sibirican hybrid?

It turns out that this iris has been crossed extensively – very extensively – with others in the iris series Sibiricae – which is one step up the iris family tree from the species I. sibirica. You can tell by the cultivar names that the breeders of this genus are passionate about their subject matter and quite possibly American. I say that because after looking at the photos on line, I wonder if our large blue variety is ‘Blue Moon’ or maybe (wait for it) ‘Over in Gloryland’. Mark is hoping for the latter.

The big blue and the new yellow – these will be named clones. We just don’t know the names.

The new yellow that Sue brought me from Bill Robinson still had a flower on it and is very pretty. Bill had lost the name but, like the other three, it will be a named clone. I wonder if it is ‘Butter and Sugar’ or ‘Dreaming Yellow’. My guess is that ‘Caesar’s Brother’ and the white one I have are both species selections, so pure Iris sibirica while the larger flowered mid blue and new yellow are named hybrids from a breeding programme. It appears that the sibirican hybrids are not unlike the so—called Dutch irises and indeed the Japanese Higo irises in their complex breeding lines which have mixed up the genetics so much that the debt to the original species is quite distant. Before any readers get all purist, yes it is important to keep the world’s gene reserves going and not to lose the original species, but the hybrid vigour that comes from mixing up the original genes is often what gives us better performing, more reliable garden plants.

Our Higo iris season is just starting and that is a time of special delight.

 

 

Just another week in the Garden of Jury – late spring, umbrellas and bird’s nest or two

Umbrellas are a part of our lives here. We own quite a few of them and use them often to move around the property. That is because it rains quite a bit and the rain can often be torrential. We get 150cm a year (60 inches). I try and keep the respectable brollies that are in good condition tucked away for when visitors need them, confining us to the somewhat derelict ones. When I say we own quite a few, I mean getting up towards 20 of them and I don’t want to end up with 20 old, crusty brollies. Here I am, drying out some of the better ones to put away again after a garden tour last Sunday.

The tour was a small group of British and American gardeners, led by a tour host whom we particularly like, which is why we agreed to their visit when the garden is otherwise closed. It is a very different dynamic to host tours with a knowledgeable leader and plenty of time for a leisurely walk around followed by morning tea. We really enjoy their company and that has not always been true for garden tours down the years. The more you get, the less personal the experience and, I am sure, less rewarding for the visitor too. The rain didn’t even matter much and it stopped soon after it started.

The English visitors felt right at home as soon as we reached the park and they saw the meadow although one of them marvelled, looking back and seeing our native tree ferns growing amongst the trees – they are self-sown here but very highly valued in the UK. Though truth be told, the most common tree fern grown overseas is the Tasmanian species, Dicksoniana antarctica.

Iris sibirica, Stipa tenuissima and common fennel in the morning light

I showed them the progress on the new garden area and those from colder climates were simply amazed at the growth rates we get here, it being a mere sixteen months since I started planting this area. The other side to that coin, of course, is that while we get a quick result we have to start thinning and managing the growth much earlier. The Iris sibirica are looking particularly good this week and stand well above waist height. We only have three different forms of this iris – the deep ‘Caesar’s Brother’, a white form and the one above which may or may not be ‘Blue Moon’. If I see other colours being offered, I would be tempted to buy more having found how spectacular they can look when massed as single colours.

The simple charm of a grey warbler nest

Behold a grey warbler nest. These are exquisite, small creations that hang from branches but this one had broken off in the recent winds. The migratory shining cuckoo is entirely dependent on the grey warbler for its continued survival because it pressgangs in the warbler into fostering its egg and then the hatchling. I asked Mark how the cuckoo, a larger bird, managed to get its egg into the nest. He is fount of considerable knowledge on these matters and he tells me the cuckoo enters through the hole, lays its egg and then forces its way out the side. The little warbler then repairs the nest and hatches out the cuckoo’s single egg with its own eggs but the larger cuckoo hatchling pushes the baby warblers or warbler eggs out of the nest. Before you worry too much about the warblers, it is the second clutch of eggs they raise that can be supplanted by the cuckoo in the nest and the warbler population is not under any threat at all.

I have a collection of birds’ nests and have been wondering how to display them. I have at last found a suitable tree skeleton that I think can be severed and brought under cover so I can tie the nests to the bare branches. Whether I can do it without it looking terribly naff remains to be seen.

Gardening is a wonderfully cyclic affair. Is there anybody as finely tuned to the seasons as the keen gardener? Yesterday was the first pick of the roses for the season. All but two of these have such scoury foliage that they have been banished to Mark’s vegetable garden (a large area that he refers to as his allotment) so the only reason they still survive is for the cutting of the blooms. Not only is gardening cyclic, it can also be distinctly ephemeral. But often those ephemeral pleasures can be the most charming on the days when they are at their best.

The roses used to grow in borders surrounding the sunken garden before I cut my losses on their awful foliage and stripped out the area for a more sculptural simplicity 

I think it looks better now for the simpler appearance

Flagging away the flag iris

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The first time I realised there was a problem with our flag irises was when Mark intervened to pull a photo from a House and Garden feature on our garden a few years ago. It was a view similar to that above. “It’s a weed,” he said. “It is embarrassing to be shown with a weed.” It has taken a while, but this week, I have dug out the last of it.

The offending flag iris

The offending flag iris

The problem with Iris pseudacorus is its resilient and invasive ways. It can survive in water, even in salt water, beside water, on water as a floating mat of rhizomes and even just on heavy soils and flood-prone areas. It is also poisonous to both humans and stock so is not controlled by animals. It is on most New Zealand weed lists and some regional councils require active management to control its spread.

Behold the offending rhizomes

Behold the offending rhizomes

Our flag irises have never set much seed, though all the descriptions say that seeding is a problem. We would have acted faster, had we seen threatening seed set. But the rhizomes, the rhizomes! They are sign enough of an issue. They form a dense mat both on and just under the surface. It reminded me of digging out wild ginger with their ability to form a solid barrier, choking out other growth. It was heavy, muddy work digging them out and prising stray rhizomes from farthest reaches with me, precariously balanced. I did not want to end up in the stream at this time of the year.

We had them planted by running water; the upper reaches of the Waiau Stream flows through our park. It was clear that floods or any disturbance of the rhizomes could cause some to wash downstream and from there, populate the countryside. It would not have been an issue had they been by a self-contained pond with no means of escape.

True, we grow Primula helodoxa and that is sometimes flagged as a weed issue by waterways but we dead head it. It is the seeding that is problematic with that plant.

Iris sibirica

Iris sibirica

Lovely Higo irises

Lovely Higo irises

and Louisiana iris

and Louisiana iris

Fortunately there are alternatives to the flag iris which do not seem to be a weed problem and are arguably considerably prettier.  Iris sibirica, the Higos and the Louisianas are all happy in similar conditions and give us a League of Nations in our park – Northern Europe and Siberia, Japan and USA. We just happened to have plants of all hanging about waiting to be planted. So while the three patches of flag irises are now muddy and apparently bare, in a few months’ time, they may even be flowering again in hues other than yellow.

036We are enjoying the water meadow effect we are achieving in that area of the garden.

More Louisianas that Mark has been raising to plant out

More Louisianas that Mark has been raising to plant out

 

 

Singing the praises of blue flowers

???????????????????????????????I am firmly of the view that you can never have too much blue in the garden. While green is effectively colour neutral – every garden has green and usually in abundance – blue is the versatile colour that fits in with all others. The addition of a little blue can lift a pastel colour scheme, add complexity to a white garden, make orange zing or stand as an equal partner in a blue and yellow border. No matter what the dominant colour scheme is, blue will fit in.

Eryngium planum

Eryngium planum

Eryngium planum

This summer flowering perennial has beautiful blooms which look like steel blue teasels and last for many weeks. Plants form tidy rosettes of foliage at ground level and the slightly prickly flower spikes can reach a metre high. Unfortunately, the plants need support – either staking individually or growing through taller plants, although the form sold as ‘Blue Hobbit’ is reputed to be lower growing, thereby avoiding the need to stake. Full sun and good drainage are the rules for growing eryngiums. While often referred to as sea holly, that is more correctly applied to E. maritimum which can be seen growing wild on the coast of Cornwall.

Grown from seed, plants will flower in their second season. Both Kings and Egmont Seeds have eryngiums or you can try your local garden centre.

Nigella damascens

Nigella damascens

Nigella damascens

Love-in-a-mist, as this summer annual is oft referred, has an ethereal lightness which makes it appear to dance through the garden. The foliage is so fine that it can be described as lacy and it takes up next to no space in the sunny, summer garden, combining well with roses and perennials. It does come in pink, white and purple tones as well now, but nothing beats the more common, pure blues in my opinion. Once flowering has finished, even the seed pod is attractive – a bubble-like capsule not dissimilar to a swan plant. Seed is widely available and once you have established plants for the first season, leave one or two to go to seed and it will keep returning in subsequent summers.

Jacaranda mimosifolia

Jacaranda mimosifolia

Jacaranda mimosifolia

There are not many blue flowering trees which may explain why large parts of the world have fallen in love with the summer jacaranda. It is native to Bolivia and Argentina and is fully deciduous. Unfortunately, this does not make it hardy and it is a tree for the warmer north or mild coastal areas of the mid north. It is usually regarded as subtropical but if you have excellent drainage and only the occasional light frost, you can extend its range. In return, it will reward you with a beautiful mass display of lilac-blue summer flowers and a carpet of blue petals below. Over time, it forms an open, airy tree reaching 8 to 10 metres in height.

If your local garden centre cannot find you a plant, Trees & More in Tauranga have it listed for sale.

Daphne genkwa

Daphne genkwa

Daphne genkwa

A lilac-blue daphne? Yes indeed. D. genkwa is as spectacular as any shrub when flowering, though rather anonymous at other times of the year. Unlike most daphnes we grow in the garden, it is fully deciduous with willow-like leaves and arching growth. While it is lightly scented, it is grown predominantly for its early spring floral display. This is not a plant that likes to be moved or trimmed so give it a permanent location with plenty of space to grow – at least 2 metres in diameter. The back of a border with lower growing plants in front will allow it to star when in bloom and remain unobtrusive at other times.

Genkwa is not rare, but it is difficult to propagate because it has to be done from root cuttings so it is not widely available. Ask a good garden centre to see if they can source it from one of the few growers producing it in New Zealand.

That is a true blue verbascum. (Photo: Thompson and Morgan)

That is a true blue verbascum. (Photo: Thompson and Morgan)

Verbascum Blue Lagoon

You will have to hold your breath for this one. As far as I know it is not yet available in New Zealand but we are waiting in hope that it may be imported some time in the near future. It was first released at the 2012 Chelsea Flower Show in London and is a remarkable colour breakthrough in large-flowered verbascums. It appears that it is a genuine pure blue and, according to the renowned seed company Thompson and Morgan, whose plant breeder is responsible for this selection, it is perennial, albeit probably a shortlived perennial. Many of the verbascums are biennial, flowering in their second year, setting seed and dying. Blue Lagoon offers the promise of spires of pure blue in the late spring garden without the problems of the fussier delphiniums.

Iris sibirica

Iris sibirica

Iris sibirica

This clumping iris is one of the easiest to grow, flowering from mid spring onwards with rich blue flower heads held above grassy or spear-like foliage. Generally the foliage is about 50cm high and the flowers reach 70cm. It originates from central Europe, Turkey through to Russia so it is hardy to cold winters. It grows best in sun to partial shade with heavier soils which don’t dry out. This is a plant which can be left undisturbed for several years while the clump gently expands. Plant it with large leaved perennials like bergenia ciliata or ligularias to keep an attractive contrast in summer foliage, long after the flowering season is over. It is a little untidy when the foliage dies off in winter but that is its only disadvantage. Iris sibirica is widely available from nurseries and garden centres.

Meconopsis or Himalayan blue poppy

Meconopsis or Himalayan blue poppy

Meconopsis or Himalayan blue poppy

Nothing matches the electric blue that is sometimes found in meconopsis though, as these are seed grown, the shade can vary. There is something about the simplicity of a simple poppy flower in pure blue – a mere four petals surrounding golden stamens – that is completely beguiling. Unfortunately, they can be very difficult to grow and are usually a waste of time for gardeners at the warmer end of the islands. They are alpine meadow plants so are going to perform better in conditions with cold, drier winters. Plants available in New Zealand are often listed as M. X Sheldonii which is a cross between betonicifolia (which is biennial, flowering in its second year) and grandis (which is meant to be more perennial). These are deciduous plants and too often they fail to return in the second year, as many gardeners will attest. But if you can find the right conditions, they will enchant you in late spring. If you buy a plant, remove the flower head in the first year to allow it to put its energies into getting established, rather than weakening itself by flowering and setting seed. Seed is best collected and sown in trays rather than left to fall in the hope that plants will naturalise themselves.

Seed of M. betonicifolia is available from a number of sources, including Egmont Seeds. Plants are sometimes offered from southern nurseries, including Wake Robin Nursery in Balclutha.

Cordyline stricta

Cordyline stricta

Cordyline stricta

New Zealand does not have exclusive claim to cabbage trees. The lovely blue flowered C. stricta hails from coastal New South Wales up into Queensland but is surprisingly hardy. It will take light to moderate frosts and coastal winds and can grow in full sun to shade. One of the big advantages as a garden plant is that the caterpillar which attacks our native cordylines is also native and appears to shun foreigners, so C. stricta does not get that chewed, motheaten look of our own cabbage trees. Stricta is clump forming and individual stems can reach about 3 metres in height. In summer, many panicles of lilac blue flowers appear, lasting for several weeks. Unlike our native varieties, they lack any scent.

Stricta is a versatile plant that can be used as a specimen or combined with a tropical, succulent or even a shaded woodland look. It also makes a handsome large container plant.

Cordyline stricta will be available in some northern garden centres but also sometimes on Trade Me and from Russell Fransham Subtropicals in Matapouri Bay.

Moraea villosa or peacock iris

Moraea villosa or peacock iris

Moraea villosa

This South African plant is commonly known as the peacock iris as its three petalled flower resembles the eye of a peacock feather. While the colour is variable, the blue or blue and white forms are the most common. Individual flowers are short-lived but each stem produces a succession of blooms in early spring. Held up on wiry stems, they can appear to dance lightly above the garden. These plants grow from corms and will do best in free-draining or sandy soils in full sun. The foliage is long, fine and grassy but gets a little scruffy before it dies down in early summer. Once you have Moraea villosa, it multiplies readily both from seed and the corms but we have not found it to have weed potential.

While not rare, this is one of those odd bulbs that you are most likely to source through Trade Me rather than finding it offered for sale in garden centres.

First published in the New Zealand Gardener and reprinted here with their permission.

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