In the Garden: January 5, 2012

A fortnightly series first published in the Weekend Gardener and reproduced here with their permission.

I am very selective about container plants these days

I am very selective about container plants these days

As summer takes hold, I am grateful that I have dramatically reduced the number of plants I grow in containers. I am not particularly reliable at hand watering and there is nothing worse than feature plants in pots, troughs or containers that stand out because they are gasping for water, drooping and defoliating badly. It is also very difficult to get water into potting mixes which have dried out completely because the water just flows straight through. A squirt of detergent can act as a surfactant and help water absorption. Because I only grow bulbs, the odd large bonsai or choice shrubs in pots, I never add water retention crystals. With our high rainfall, these products keep the potting mix too wet, rotting out the roots and the bulbs. This is particularly so in winter when plants don’t want to live with their roots sogging in cold, wet conditions. The only time I have used water retention crystals was in my hanging basket phase (it passed quickly) and when I tried seasonal pots of annuals – which also passed quickly. We went on holiday leaving lovely big pots of blooming pink petunias and blue ageratum and came back to pots of withered, dead plants. The water retention crystals were not enough. I decided then and there that I preferred a more permanent and sustainable style of gardening.

In issue 323 of the Weekend Gardener, I wrote about plunging pots to reduce watering requirements while still keeping individual plants featured. It only works if the pots are porous (I keep to terracotta) and they still need the occasional water but they are much easier to maintain over summer. I have found I need to keep an eye out for slug infestations around the plunged pots. They like the damp, dark conditions and can take up residence on the outside surfaces of the pots. I found an entire slug convention on one pot recently but at least it encourages them into one area for easy eradication.

The peaceful, neverending task of hoicking out flat weeds

The peaceful, neverending task of hoicking out flat weeds

Top tasks:
1) Weeding is never ending. At this time of year, some of it can be done quickly by push hoe. If any weeds get away on us and set seed heads, we try and remove them from the area but the aim is always to get them before that stage so they can be left to wither and die in the summer sun.
2) The autumn bulbs will be starting to move very soon, putting out fresh roots. I need to thin the Cyclamen hederafolium, Colchicum autumnale (the autumn crocus) and check over the clumps of nerines (mostly sarniensis hybrids) before they are growing.
3) When I feel the need to do something quiet and mindless, I head out with the lawn tool to dig out flat weeds in the grassy areas of our park. It is a bit like King Canute holding back the sea but it makes me feel more virtuous than spraying and it is a soothing summer occupation.

Tikorangi Notes: Friday 30 December, 2011

Latest posts:
1) Finally found it – the proper Jacobean lily (though neither Jacobean nor a lily): Sprekelia formosissima
2) A touch of mea culpa on a very public spelling error – and a continuation of discussion on pohutukawa and other members of metrosideros family.
3) Grow It Yourself – or maybe not in the case of pizza counting as a vegetable in American school lunches.

Wet pigeons, awaiting the erection of the wedding marquees on the front lawn this morning

Wet pigeons, awaiting the erection of the wedding marquees on the front lawn this morning

Tikorangi Notes:
The rain it raineth, unrelentingly alas. Mark’s pidgies are looking sad on the front lawn. I am merely contemplating the arrival of the marquee company, due any minute. On the bright side, at least the wedding party tomorrow did plan on two marquees and not trust to fine weather. And we have wonderful drainage so the grassed areas don’t get boggy and mucky. Add to that, we own a fair number of umbrellas. And it is not the wedding of one of one our own – though it is the daughter’s best friend. Maybe the rain will stop as the day progresses. Maybe the weather gods will smile and the forecasters have the timings wrong. Weather prediction in this country is a notoriously difficult activity, given that we are long, thin islands in the midst of vast oceans with competing tropical and polar air masses. But wait, do I detect a lightening in the sky to the north?

I am privy to all sorts of information about the wedding but my lips are sealed. All I can say is watch this space… The orange toilet brushes, dropped in yesterday by the bride’s father, rather caught my attention.

It would be so nice if the rains would stop. We will battle on otherwise – this is an unstoppable event – but it would be more fun if we were not making dashes around under umbrellas.

Plant Collector – Sprekelia formosissima

The Sprekelia formosissima or Jacobean lily

The Sprekelia formosissima or Jacobean lily

You learn something every day. This bulb is what is commonly known as the Jacobean Lily, even though it has nothing to do with the Jacobeans and it is not a lily. For years I have freely tossed the descriptor around, “it resembles a Jacobean lily”, thinking more of William Morris textile design than botany. And all the time, there is a wide level of agreement internationally that the Jacobean lily is Sprekelia formosissima. Added to that, when a species name is formasana or formasanum, it usually means that the plant comes from the former island of Formosa (now Taiwan). But the unwieldy formosissima means, loosely, beautiful. In fact it comes from Mexico.

It is indeed a beautiful flower with its rich red strappy petals and elegant form. A member of the amaryllis family, it is closely related to hippeastrums. It grows on quite a tall stem, around 30cm, with just a single flower per stem but fairly long lived. Aside from the genuine lilies, there aren’t a lot of bulbs that flower in early to mid summer. It is not particularly rare but it is one of those collectors’ items that is getting ever harder to source with the shrinking plant range offered for sale these days. If you find a plant with seed, it germinates easily when fresh.

As with all bulbs, the sprekelia likes well drained, friable soils and good light levels. It can get attacked by bulb fly (as can the hippeastrums) so we go for the woodland margins to outwit the sun-loving bulb fly. Despite its Mexican origins, sprekelia is regarded as half hardy which means that it can tolerate cool conditions and light frosts.

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

Rata and pohutukawa – the metrosideros family

Pohutakawa, maybe Scarlet Pimpernel, in Hamilton on Christmas Day (photo: Michael Jeans)

Pohutakawa, maybe Scarlet Pimpernel, in Hamilton on Christmas Day (photo: Michael Jeans)

I have to start with a touch of mea culpa. I will never misspell pohutukawa again. It had never even occurred to me that I did not know how to spell it correctly. See, I had a Dunedin childhood and in the deep south, we probably had rata on our spelling lists rather than pohutukawa. At least that is my story. My only consolation in the matter is that my misspelling of the Maori name for Metrosideros excelsa apparently escaped the notice of everyone else involved with the production of the paper I write for, so I was not alone. But I was probably alone with my embarrassment. In case you missed it last Friday (before I corrected the website post), I turned the second u into an a.

As a peace offering, I give you a photo of a lovely pohutukawa in full flower at Millenium Heights in Flagstaff, Hamilton. The owner, Bronwyn, tells me it was meant to be a dwarf but it is already three metres high and it flowers profusely every year. When she said it was meant to be a dwarf, I thought initially that it might be one of the Kermadec pohutukawa (M. kermadecensis) which is sometimes used as a smaller selection – though only relatively smaller. However, I ruled that out because the Raoul Island pohutukawa flowers intermittently all year in dribs and drabs and it does not put on a mass display as shown. Added to that, it is more frost tender so it is never going to be happy in inland Hamilton. It is more likely to be a selection of the common form, M. excelsa. In fact it may even be the one named Scarlet Pimpernel (which was selected by my late father-inlaw). There is considerable variation within this species. If you start looking at trees you see over the next couple of weeks, you will pick huge variation in colour. Some look almost rusty brown from a distance, some deep red. The ones that stand out in the landscape tend to have orange tones to the colouring which gives vibrancy. It is called seedling variation – they don’t grow identical from seed. To get an exact clone of the parent, you have to propagate by cuttings.

The yellow pohutukawa are sometimes seen as a novelty. They are pretty enough in their own way but to my eyes they are nowhere near as spectacular as a good red specimen. The yellows are just another seedling variant of the same species, most common on Motiti Island. The reason you see them in mainland gardens and public plantings is because Duncan and Davies Nursery produced them commercially some decades ago – always the quest for the different and the new. It was that quest that also saw variegated forms offered for sale. These are not my favourite. I am not a great fan of variegated plants so I am unconvinced that a variegated form of our iconic pohutukawa was ever going to be an improvement on the usual forms in the wild. But because they were seen as different and new, they sold well for a while and there are big specimens around.

M. excelsa grows naturally as far south as Poverty Bay in the east and North Taranaki in the west. The pohutukawa that grows and flowers in the top of the South Island is a different species, M. parkinsonii. It tends to be rather more scruffy in its habit of growth.

The rata does not just go up, it goes along in every which way

The rata does not just go up, it goes along in every which way

It is of course the rata that is to the South Island what the pohutakawa is to the North Island, though we do have the northern rata as well. These are all the same family (so all metrosideros) but different species. Think of them being like cousins, perhaps. So the South Island rata is M. umbellata and the North Island rata is M. robusta. It is the latter that starts life as an epiphyte, living on a host tree that will ultimately die. The rata sends down roots that eventually reach the ground and develop into a strong vine. Over time, the vinous roots fuse together to form what looks like a trunk (called a psuedotrunk) so, by the time the host tree is strangled, dies and rots away, the rata can hold itself up. We have this rata here in the garden and we find that it does not just go up the host trees, not at all. In an hospitable garden woodland situation, there is little holding it back as it attempts to take over the entire area. I have to have words with it about its smothering ways. There is a limit to how much ground cover we want. Besides it only flowers on the tops and even then is but a shadow of the magnificent display the pohutukawa put on.

The southern rata is less determinedly epiphytic and can establish itself on its own roots in conditions which vary from nearly sub alpine to wet coastal forest. I recall as a child the excitement expressed by adults at the flowering of the rata in the wild, but it tends to be more a haze of red than an in-your-eye statement of summer and Christmas as with the pohutukawa. Unfortunately rampant possums have destroyed much of the impact of the southern rata in bloom.

Of the family, it is the good red pohutukawa or M. excelsa that remains my firm favourite.

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

Grow it Yourself (or not, in the case of American school lunch pizza)

Yes! Pizza. In honour of one of life’s bizarre rulings of 2011, that pizza counts as a vegetable serving. Here I was thinking that by definition, vegetables are edible plants that one grows but apparently not. Mass produced pizza with a smidgeon of a red substance which once, some time and distance past, had a debt to a tomato, can now officially count as a vegetable. One might not have been quite so surprised had the good gnomes of Brussels made a formal decree. It was the European Community, after all, that passed regulations on how bent a banana was permitted to be and they also addressed the perplexing issue of cucumbers. I can’t recall the details of that but I think it was probably on how far a cucumber was permitted to bend from a straight line. But it was the United States Congress, that fine law making body, which bowed to the pressures of the frozen food industry and reclassified pizza to enable it to remain as a healthy option (ie: counting as a serving of vegetable) on the menu of school lunches for American children.

Our diets in New Zealand may be far from perfect and we have a growing issue with obesity, but I think we have far too much respect for the Heart Foundation and the healthy tick to consider mass produced pizza as a healthy food choice. If you are worried about your weight, just ponder for a moment how many obese vegetarians you have met. I failed to come up with any. Certainly it is not common and while giving up eating meat may be a step too far for many (including me), doubling the fresh vegetable intake might be a good New Year’s resolution to make, along with trying to grow at least some at home.

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