Category Archives: Plant collector

flowering this week, tried and true plants

Elegia capenis

Elegia capensis in the new Court Garden

I lost count of the number of times we were asked about Elegia capensis during our recent open days. I have used it extensively with the grasses in the new Court Garden and it is looking rather splendid.

Its common name is the horsetail restio and the entire restionaceae plant family hails from South Africa. There are plenty of them but E. capensis  is the most common in ornamental gardens. It is not too fussy on conditions as long as it never dries out entirely and is not subjected to very cold winters.

Most visitors described it as looking like a bamboo but with feathery growth, which is apt. The new shoots come up in spring like narrow bamboo shoots, first developing brownish sheaths at points up the stem before growing the fine foliage in tiers. The stems last about three years before dying off.

When you look at the seed head, it is just as well that seed is not viable here

Our plants have never set viable seed. Whether that is because they are all one clone and they need other clones to set seed or whether it is the lack of smoke from bushfires, we are not sure. They may even be fully dioecious – needing both male and female plants to set viable seed. These are plants that have evolved to deal with frequent fires (they sprout afresh from underground rhizomes). PlantzAfrica says: “The seeds react well to treatment with smoke or with the ‘Instant Smoke Plus’ seed primer. Without this treatment the germination rate is poor.” I have never even heard of Instant Smoke Plus before.

We used to produce a few to sell in the nursery but the death rate in production was high. I have only just discovered why. We assumed that they would be similar to other plants like hostas and rodgersias that grow from rhizomes. In other words, we would lift the plants in winter, separate the rhizomes and repot them ready for spring growth. Then I read somewhere that they should be divided in February – late summer – so we tried that and it was not particularly successful either. What I have since discovered is that their roots are very sensitive, making the plants difficult to propagate by division. They are evergreen and not overly hardy so they are in growth all the time, unlike plants like the aforementioned hostas which have a dormant period. Commercially, they are more commonly raised from seed.

Where we have been successful in dividing this elegia, it has not been by taking apart the rhizomes but by cutting off large chunks of the original plant and putting the entire chunk into the new location. When I say cutting off large chunks, this requires a strong person, a very sharp spade and sometimes an axe, to take off blocks that are about 20 cm across which need to be replanted straight away. Brute strength, not high-level skill.

I see BBC Gardeners’ World describe this plant as invasive, which I think is wrong. It doesn’t seed readily – or at all here. Nor does it run below the soil surface so it is not invading. It is, however, strong growing and can make a large clump in the right conditions and that large clump is not easy to reduce or eliminate because of the solid nature of the rhizomes.

The maceaya is the poppy foliage amongst the elegia

What is setting out to be genuinely invasive is the Macleaya cordata, commonly known as the Plume Poppy which is interplanted with the elegia. We have it in a shade garden where it certainly ‘ran’ below the soil surface but not in a particularly problematic manner. In full sun in the Court Garden, it is not so much running as sprinting – in every direction including into the pristine new paths. Attractive it may be, but it is a worry. I may just have to leave it in the shade garden and find a less determined plant option for the sunny, grass garden.

Terry’s restio, as we refer to it here.

We have another restio that I picked up from Terry Hatch at Joy Plants in Drury but I am not sure where – or if – I kept its species name. It is not as vigorous as the elegia so better suited to the perennial borders where I have it planted but lacks the immediate visual charm of the deep green colour and tiers of feathery foliage up the stem. There is no such thing as a perfect plant for all situations.

Golden orbs

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Every time Edgeworthia gardneri blooms and I sniff the waxy, golden orbs of fragrance, I remember a customer from our mail order days. One who put the cuss into customer, as Mark is wont to say.

New Zealand Gardener magazine carried a full-page photo of a single golden orb and the accompanying text named us as one of very few suppliers of this plant. It is not common in NZ gardens and not that easy to propagate. A full-page photo should give a hint as to the problem. It was considerably enlarged in the image.

A reader rang, desperate to order one of the few remaining plants we had. One of the staff took the call and didn’t check to make sure she knew what she was buying. I am not saying Mark or I would have checked, but we might have. The staffer instead sold her an additional random plant as well to meet our minimum order of $35 and her plants were packed and despatched.

I have no idea what the woman’s name was but I can remember she lived in Palmerston North (here’s looking at you Palmerstonians – she was yours, all yours). On receipt of the plant, she rang to express her extreme disappointment. The flower, you see. She had no idea the flower would be so small. It looked much larger in the photo. I mentally sighed and agreed to take the plants back if she returned them in good condition. She had clearly destroyed our packing because in due course, the plants arrived back in a carefully constructed cardboard cage, with windows and air vents, even. As I recall, it cost her $27.50 to send us back $35 worth of plants. I deleted her from our data base.

Edgeworthia gardneri is the tall, willowy, multi-stemmed shrub behind the orange clivia

But every year, as I enjoy the plant in bloom, I smile wryly at the thought of what she missed out on because it is lovely. It is willowy in its growth so light and graceful, adorned by many golden orbs with good scent in late winter and early spring. It is evergreen and hails from the forests in the Himalayan foothills and is, I have just discovered, just as good if not better for the making of high quality paper as its better known, deciduous, shrubby cousin, Edgeworthia papyrifera syn chrysantha (which bears the common, though inaccurate, name of the yellow daphne).

It is just that the flower heads are the size of pingpong balls, not tennis balls, or maybe even the larger ball size used in softball and baseball.

Simple things – appreciating primula species

Many square metres of Primula helodoxa

Mark wasn’t particularly optimistic about the primula seedlings we were given some months ago. “We can’t do primulas well,” he said. I went away and thought about this and came back to him, pointing out that we can do Primula helodoxa rather too well, Primula obconica has stayed in one patch of garden for at least two decades despite minimal attention and the annual Primula malacoides pops up prettily around the place and would pop up everywhere if we didn’t restrict its spread. What he meant, I figured, was that we have not succeeded with the choice species like Primula vialii and the Inshriach hybrids which brought a range of different colours, did well initially and then just faded out.

Primula denticulata in the recently planted perennial meadow of the Iolanthe garden

More than one flower spike is forming in many of the plants which is a good sign.

This new primula is a wild form of  P. denticulata, so nothing too out of the ordinary or fussy.  It put up its first flowers a few months ago and, to my delight, is a pretty lilac blue. I am very hopeful it will do well here because it is a colour I really like. To be honest, it is more lilac than blue but that is fine. It has a good strong stem and holds its round flower head up well at 30 to 40cm above the foliage. What is particularly pleasing is that the stronger plants are putting up multiple flower heads. It is always encouraging to get a new plant and even better when you get given over 20 of them rather than buying a single plant and then trying to build it up. Time will tell if it settles in happily over several years and whether it is a suitable candidate for naturalising in meadow conditions but the early signs are good.

The only two polyanthus I kept on the left, Primula vulgare or the wild English primroe in a tiny bunch of nostalgia on the right

The primula family is huge with around 500 or more species. The English primrose, Primula vulgaris, was one of my English mother’s favourite plants in every garden she made – and in her lifetime she made many. I just have one patch of it because the foliage to flower ratio is rather too high in our mild climate but I like to keep it out of nostalgia. As a child, my mother encouraged me to pick flowers (always with long stems, she stressed, and the rule of thumb was that I could pick anything except the roses) and my bouquets were often primroses and grape hyacinths.

Primula malacoides – easy to pull out if it is in the wrong place but charming enough to allow it to gently seed around some areas

Polyanthus and auriculas also belong to the primula family. I am never sure whether I like auriculas. I can admire the curious flower markings but I am not sure how or where one would place them in a garden situation without having them look like a fake flower that was bought from The Warehouse. Maybe this is one of the reasons for that odd feature of the auricula theatre favoured by some UK gardeners – they couldn’t work out how to place them effectively as garden plants, either. Fortunately, this is an academic question here because auriculas are a plant that does way better in colder climates than ours.

Primula obconica has staying power here

Polyanthus are a cheap and cheerful late winter and early spring plant in many gardens. When our children were little, we would sometimes call in to a local hobby grower and let the children select the colours they liked to plant at home. Over time, I have cast out all polyanthus here except for a pure yellow one that I keep in one spot and a good performing white that I have in another area. They lack the refinement of the species that I now prefer; they need regular digging and dividing to keep them performing well and they tend to attract weevils. The weevil larvae show as wriggly white wormy things, usually about half a centimetre long. Years of nursery work instilled a fear of black vine weevils. Perfectly healthy-looking trees and shrubs in the nursery could suddenly flop overnight and forensic examination would reveal that the plants had been ringbarked by weevils just below the level of the potting mix. It took a lot of effort, changed practices, expense and the use of a rather strong chemical to eradicate weevils from the nursery. I am not keen on getting major infestations of these critters in the garden.

My rule of thumb is that I squish any white wriggly things I find in the garden soil. I don’t mind doing that for the new lilac blue prims if they settle in here for the long haul.

Primula denticulata – seedling grown so there will be variation in the flowers

Spot the difference

I was going to write a piece this week shouting that now IS the very time we should be talking about climate change, aimed at the Australian prime minister, Scott Morrison, who left his burning country to holiday in the cleaner air of Hawaii, declaring that now is not the time for knee-jerk reactions to a major drought and extreme fires and neither is it the time to talk about climate change.

But the majority of Australians voted that man and his government in this very year and I decided that maybe I would leave it to those voters to reflect upon their collective decision and respond to their own environmental crisis. Instead I will focus on flowers.

Hydrangea petiolaris, resplendent in full sun, although it has its roots on the cool side of the fence. Most climbers appreciate a cool root run.

Both the common climbing hydrangea, H. petiolaris, and the less common Schizophragma hydrangeoides are in full bloom here and I have never lined them up side by side to compare them. We produced both commercially in our nursery days but concentrated more on the allegedly more refined and desirable schizophragma. What were the differences, I wondered, in visual terms?

Hydrangea petiolaris to the left and the white and pink forms of Schizophragma hydrangeoides. Petiolaris looks creamier because it is an older flower grown in full sun. 

Not a whole lot, was the answer when I lined them up. The pink form of the schizophragma is  indubitably a different colour – rosy pink sepals, not white. H. petiolaris has more fertile flowers (the central tiny blooms on the lace-cap) and somewhat smaller outer petals (ray florets or sepals). It makes it appear a little bit heavier perhaps, than the light dancing of the sepals on the schizophragma. The hydrangea also has larger leaves overall. All of them have a light scent with a slight variation between the two species but nothing of great note.

Schizophragma hydrangeoides ‘Roseum’

Botanically, there is a difference. They are distinct species, though from similar parts of the world (woodland Asia, particularly Japan) and liking similar conditions. Schizophragma is nowhere near as common as H. petiolaris and has the reputation of being slow to establish. But I planted that petiolaris many years ago and it took several years to reach its stride, too. Mark reminds me that the reason he went for the schizophragma over petiolaris was because the latter would not set flowers on young plants.

Schizophragma hydrangeoides

Plantspeople and those with refined visual sensibilities will pick the difference. I prefer the lighter, more ethereal look of the schizophragma. But overall, I concluded that Mark’s ‘man on a galloping horse’ analogy applies. A man (or woman, presumably) passing on a galloping horse would not pick the difference. To be honest, most gardeners wouldn’t either. They are both lovely at their peak and well behaved as far as climbers go.

Seven long years to bloom and then it dies – Cardiocrinum giganteum

The giant Himalayan lilies are coming into bloom. Cardiocrinum giganteum. It is the biggest of the lily family, hailing from areas like Tibet, Bhutan, Assam, Myanmar, Nepal and Sikkim.  It feels a bit of a triumph that we now have this bulb naturalised here. We haven’t planted any for many years and just allow them to grow where they pop up from seed.

The largest lily of them all – Cardiocrinum giganteum

These are not lilies for the home gardener on a small urban section. The flower spikes often reach three metres here and have been recorded at up to five metres. Fortunately, the stem is such that they can hold themselves up.

Usually six years of foliage and in the seventh year, it puts up an astounding flower spike

The main obstacle for most gardeners is that the bulb takes about seven years before it flowers and then it dies. Fortunately it makes offshoots around the main bulb as well as setting seed but those offshoots can take another five years minimum before they flower and the seeds take seven years. These are not lilies for the impatient gardener. And, while very fragrant, the flowers are a long way up so unless you have a grove of plants flowering at the same time, you are unlikely to get the benefit of scent. In the intervening years, they just form a clump of large, heavy textured, heart-shaped leaves that are reasonably anonymous.

Typically, these plants need cool, open, woodland conditions with soils which never dry out and are rich in humus. Those are pretty specific conditions.

The top photo is one of those really, seriously peculiar plant combinations that are a characteristic of many New Zealand gardens – a self sown Cardiocrium giganteum from the Himalayas, flanked on the right by Pseudowintera colorata (commonly known here as the mountain horopita or pepper tree) with Dracophyllum latifolium behind (both NZ natives) and then what we know as Aloe bainseii but is now, apparently, Aloidendron barberae – the tree aloe from southern Africa. It is a veritable United Nations of plants here.