Tag Archives: collospermum

The weight of epiphytes

Over a century of epiphytic build up

When branches fall here, they often bring down a mass of epiphytes with them. It seems likely that, in some cases, it is the weight of those that causes the branch to fall. A combination of mature trees and a benign and humid climate means that epiphytes are a significant feature of our canopy. ‘Widow-makers’, Mark says, utilising the term for things that have the potential to fall from above and kill. It is a gender defined term, which I guess comes because it has a longstanding application in forestry which remains a traditionally male occupation.

There is an entire self-sown and self maintaining environment in this one tree

One of the characteristics of New Zealand native forest is the high incidence of epiphytes which are simply organisms (in this case, plants) that grow on the surface of another plant, getting moisture and such nutrients as they need from the air and rain and then from the debris that builds up around them. Because these epiphytes are perched up trees, they are vulnerable to drying out so are more commonly found in areas protected by other trees rather than on solitary specimens standing in exposed isolation. We also get regular rain here and have high humidity levels no matter the season. Add to that the fact that our native forest and bush is almost entirely evergreen. There are very few deciduous natives – a total of only 11 different species that are fully deciduous in winter. Most New Zealand gardens use a wide range of evergreen plants and shrubs, usually outnumbering the deciduous selections. So we have situations that are hospitable to epiphytes.

Add in to that mix, maturity. Because we have many well-established trees here, some dating back close to 150 years, there has been time for epiphytes to get a grip on their hosts.

Drooping spleenwort and leather leaf on the trunk of a tall queen palm

Where do these plants come from? Mostly a combination of wind and birds. Some of our trees have entire mixed colonies growing in them. The dominant epiphyte here is the collospermum, C. hastatum, but we have other species of both collospermum and astelia perching up high too. Also assorted ferns, particularly the native climbing ferns, Pyrrosia eleagnifolia or ‘leather-leaf’ fern and Asplenium flaccidum or ‘Drooping Spleenwort’ which is prettier than it sounds. We even get native orchids appearing in these epiphytic colonies but NZ native orchids are perhaps best described as being very subtle in appearance.

The host tree is leaning badly, the twining vines and thicker trunks are all southern rata

The rata 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. That rata is an epiphyte, relying on an established tree to climb. Unlike most of the perennial types of epiphyte, it can eventually kill its host. In forest conditions, the rata is so well established by then that it can stand on its own, forming a hollow-trunked tree (the hollow centre being where the host tree has decayed away). We think it far more likely that our rata will not be sufficiently anchored to the ground to stay standing. The nearly deceased host tree – a eucalypt – has developed a definite lean and we think the whole shebang may fall sooner rather than later.

Like an octopus, Prunus yedoensis ‘Ivensii” with epiphytic collospermum

I did get the ladder and do some tree climbing to take out most of the collospermum from the Prunus yedoensis ‘Ivensii’ because I like this flowering cherry and I could see the collospermum were getting the upper hand rather than maintaining an equilibrium.

Generally, we just leave the epiphytes alone. Sometimes the weight will get too much and massive clumps will fall, often bringing down branches on the way. They are usually so heavy we have to dismantle them to remove them. In times gone by, Mark used to follow the Orchid Society practice of gathering up the decaying gigi (fallen collospermum) to use as potting mix for the growing of orchids. That was before the days of granulated bark potting mixes. Left to their own devices, epiphytes are just a part of nature – a naturally occurring matrix in fact. It adds an upper layer of interest to the garden while also creating its own ecological environment quite independent from human intervention.

Whenever we have to do a clean-up that involves fallen epiphytes, we just relocate the largest pieces we can manage to the back areas of woodland where they can continue to provide habitat and add diversity.

Mark is surveying a sizeable branch brought down by the heavy burden of epiphytes

In the meantime, there is another branch waiting to fall…

Tikorangi Notes: Things that go crash in the night, recommended hostas and our pretty meadow

It was not Dudley crashing in the night but he did look somewhat noble down in the meadow yesterday

Things that go crash in the night. On a dead calm night, both of us heard the unmistakeable noise of a large branch falling to the ground. I was pretty sure it was not an entire tree because there was no whump as it hit the ground so it clearly did not bounce, as large trees usually do. Morning light revealed that it was as expected – a branch from one of our old man pine trees. In this case it must have fallen 30 or 40 metres to the ground and it appears to have taken out the two camellias that had more or less staged a revival from being clipped by the last two falling trees.

The damage from a falling branch

As usual, we will gather all the pine cones and get out what firewood we can but it appears that there is some surrounding damage this time.  We are philosophical. It is just part of gardening beneath huge trees that are now up to 145 years old. The fallen epiphytic collospermum may be a clue as to why the branch fell. There will be a big weight in just that chunk of vegetation sitting on the branch. The birds spread the seeds and they can germinate, grow and hang on for grim death up high.

It may have been this massive epiphtye that caused the branch to break

Blue hostas raised from seed

After last week’s post on Hosta Jade Cascade (which is settling in just as well in other parts of the garden where I planted it out), I have been looking anew at the varieties that are thriving on zero maintenance. Some of the enormous clumps will have been in 20 or more years now and just keep reappearing a little larger each season. A lot of our big blue clumps are unnamed, raised from seed – some of them from Hosta seiboldiana.

Hosta undulata variegata is getting smaller, I think, over the years

In a big garden, we need big clumps of plants to have an effect. In this area, the stand out gold is Goldrush, raised and named by Felix Jury. It is a terrific performer and puts up a good floral display of purple flowers. The blue is a seedling. Neither of us can name the variegated hosta which is not the showiest of varieties but it has done well and that is not to be sniffed at. There aren’t many variegated hostas that we have planted that have thrived in garden conditions under a regime of benign neglect. Too many, like this poor little specimen of H. undulata variegata have reduced in size over the years, rather than grown larger.

In the smaller growers, variegated Golden Tiara is again not particularly exciting but a very good garden plant. The blue green, little Flora Dora has increased freely and gold Blonde Elf has also surprised me with how well it has established for a very small grower. On the other hand, I haven’t seen dwarf Kabitan for a while so I wonder if it has shrunk away altogether, which would be a pity.

It looks like Guacamole to me and I am not making up that name

Of the variegated types, this one which I think is Guacamole from memory, is doing very well. It is a reverse variegation sport of Hosta Fragrant Bouquet. I will have planted out large specimens of the latter at a similar time as Guacamole but I have yet to find them in the garden, which means they are not growing as strongly at all.

Sum and Substance

Add Blue Boy as a good, reliable garden plant. We stopped growing it commercially towards the end of our time because there were other, showier, bluer cultivars that sold more readily but while they are not starring in the garden, Blue Boy is a strong survivor. That is my short list of top performers as garden plants that have caught my eye this week and that have proven themselves over several years. Oh, Add Sum and Substance which is surprising me by its willingness to grow suitably large in the spot where I planted it.

As a postscript to the hostas, these are grown with no slug bait or slug and snail control. We now have such a rich bird life that they enable us to grow these plants without having to protect them. Well, I assume it is the birds carrying out this task because there is no reason at all for us to have any fewer slugs and snails to start with than anybody else gardening in similar conditions.

The meadow! The meadow!

At the risk of repeating myself – but we all know that gardening is a seasonal activity that is, by definition, repetitive – the meadow below is bringing me great joy as the Higo irises all come into bloom, interspersed with the Primula helodoxa that has been at its peak for a full month now. What more can I say?

 

Plant Collector: Prunus x yedoensis ‘Ivensii’ with collospermum

Prunus x yedoensis 'Ivensii'

Prunus x yedoensis ‘Ivensii’

Trying to delve into the origins of flowering cherries of the Japanese types was far more complex than I expected so I will keep it simple and say that this is a hybrid, sometimes known as the ‘Yoshino Cherry’. This particular variety was named at the UK’s famed Hillier Nurseries because of its weeping habit and wonderful tortuous branches. Our mature specimen looks a bit like a rigid octopus and has a near flat top. Prunus do not have a long flowering season but while it is in full flight, it is a veritable froth of white single blossoms reputedly with a sweet almond scent but I wouldn’t buy this as a fragrant tree. Even when mature, it is only a small specimen – maybe four metres high and about the same in width.

The rather odd effect of the native epiphyte, Collospermum (probably hastatum) looks like tuft of hair poking out of the centre. These flax or astelia-like plants are sometimes referred to as the perching lily or, less romantically, widow-makers. That is because they can be large and heavy and have a habit of eventually falling out of the tree. Other than that, they do no harm.

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