In this section I bring you some of the rare and unusual conifers on the market

There's a surprisingly large chunk of the conifers which is largely unknown outside specialist nurseries and collections. Many of these are coveted treasures tended lovingly in the gardens of the keen collectors, where they are prized for their unusual features, their obscurity, and for the extra sense of achievement the collector gets from growing something just a bit special.

However, whilst some species are the domain of the conifer 'nut' (surely 'cone'?), others are freely available through specialist nurseries who will be more than happy to help you choose that special something. In my previous section 'Conifers- time to look again?' I concentrated on forms suitable for general cultivation, but in this section I'm going to concentrate a little more on specific plants which I have come across, and few of which I am lucky enough to grow in my own garden. I start with something spectacular!

PINUS DEVONIANA (syn Pinus michoacana) This is one of the most amazing pines I have ever seen! Coming from Mexico, this pine boasts the longest needles of any known, in the case of the one below a massive 14" long (35.5cm)!

Sadly it's not believed to be particularly hardy which is a real shame, but may prove suitable in a pot in colder areas. One internet source puts the hardiness of Pinus devoniana as USDA zone 9 which seems to be somewhere around -5 deg C. You may well increase it's hardiness by giving it very sharp drainage, but this hasn't been tested. Here in Cornwall it should grow outside (there is apparently a tree in Plymouth), but even then I can't give you an ultimate height as few have been grown in the UK, and details are sketchy about it in the wild.

You'd have thought that being a tree rich in lovely flamable resin in an area prone to forest fires would be a disadvantage, but this pine has got around that. Even on young plants the trunk has a thick bark, and this protects the tree from long-term damage. The fire will burn the needles quickly but leave the trunk largely unscathed, so the plant can redevelop from dormant buds.

Clever- you can't keep a good tree down! There has been a lot of interest in this plant, and quite rightly so! Anyone who sees it loves it.....

...including me! www.duchyofcornwallnursery.co.uk

HALOCARPUS BIDWILLII This is not the most exciting plant on the planet but is a nice enough thing. In the Podocarpus family (more on Podocarpus later), this is a shrub/tree endemic to New Zealand where it grows as a tree in low altitude areas but a shrub in more exposed high altitude. In the UK garden it sort of.... grows! That's all I can really say about it I'm afraid. However it does make a nice shrub for a foliage effect- like the Junipers, Halocarpus has different juvenile and mature foliage. The mature foliage is wiry and open (and makes quite a nice effect overall) whereas the juvenile foliage is tight and compact. Neither type of foliage is particularly exciting on it's own, but the overall effect when the two are together is rather nice. It's a good idea to clip it in order to keep the two foliage types.

The mature foliage of Halocarpus bidwillii. Below is a picture of a medium sized plant in all it'a glory.

PHYLLOCLADUS TRICHOMANOIDES VAR. ALPINUS Bit of a mouthful, but a distinctive small tree. Rather than having the needles of an ordinary conifer (or even the leaves of any plant) this has flattened photosynthetic leaf stalks called 'phylloclades'. The effect to the casual observer is of upward facing waxy leaves in a silvery colour. Rather importantly the 'type' of Phyllocladus you buy determines the shape/appearence of your eventual tree; if you buy a plant collected at high altitude you will have a slower growing and more compact plant, and from a lower altitude a more open specimen. Both forms are, I reckon, rather nice, and the more open tree would like a distinctive specimen for a sheltered spot, maybe instead of a Pinus parviflora cv.?

 

The foliage of Phyllocladus.

ARAUCARIA Known commonly as the 'Monkey Puzzle', Araucaria araucana is a classic suburban tree, despite being rather unsuited to this purpose! The Victorians loved it for it's strong structure and unusual form as a young tree, and many were planted in the tiny front gardens of Victorian houses. You must, however, appreciate that very few people of the time had any concept of just how big these trees could get! Many must have been felled over the years as the Victorian ladies and gentlemen realised that their prize tree was a monster, blocking the light from the windows and generally taking up rather too much space! However a few remain, and if you tour the streets of a town with Victorian villas you may be lucky to see an original. A. araucana has three main growth phases- youth, when the plant looks strong and perfect; middle age, where the plant grows very tall and looks scruffy (and also drops it's lower branches!), and old age, where it looks like the umbrella we all know. This Araucaria is from high altitude forest in Chile where, according to Roy Lancaster, it grows with Embothrium (Chilean Flame Flower).

Not many people know there are other species of Araucaria. A. heterophylla is known as the 'Norfolk Island Pine', named after Norfolk Island in the South Pacific (where, as you've guessed, it comes from!). A reasonably well known houseplant you have to see a reasonably sized A. heterophylla to recognise it's family- the tiered branches or soft green needles are strangely familiar but quite different from A. araucana.

Picture courtesy of Jim Stephens. I think the one above grows outside on Tresco, but everywhere else it is a houseplant, although it would really enjoy a summer outdoors.

Even Australia boasts two Araucarias. A. bidwillii (named for J. C. Bidwill- a botanist) is occasionally found here in the South West to tempt those who like to run a risk! A. bidwillii is a VERY rare tree here in the UK because it is not hardy outside Cornwall, and I would be doubtful if it has a viable future as a houseplant! The Encyclopedia of Australian Plants (pub Lothian) gives an ultimate height and spread of A. bidwillii as 30-50m x 10-20m! Looking further in the write-up, they say that "young plants make handsome pot specimens and are highly prized as indoor plants in Europe and the USA", so if you can find one for sale here in the UK then it might be worth a go....?

A. bidwillii- this plant is only young, but this foliage effect continues into maturity.

MICROBIOTA DECUSSATA This tufty little conifer is extremely rare and endangered in it's native range, but thankfully is reasonably widely available in cultivation if you keep your eyes open! On first impressions this nearly flat conifer looks very similar to a Lawson's Cypress (Chamaecyparis lawsoniana), but... flatter! However the charm really comes in winter when the whole plant goes a rather nice purple or bronze colour.

An upright form exists, called M. decussata 'Jacobsen', and two other forms are listed by the RHS Plantfinder but I have never seen either of them 'in the flesh', so can't really comment on them. 'Jacobsen' makes an almost conical shape in my garden, and is no more than 1ft (30cm) tall. If it grows taller (which it better had do!) then it will make a very nicely shaped tree for a rock garden.

AGATHIS Known as the 'Kauri Pine' in it's native New Zealand, Agathis australis is a distinctive plant which is very gradually making it into South West gardens. The tree has large waxy needles (see below) and grows massive if given time and space! Many were unfortunately lost due to logging in the late 19th and early 20th century, but the remaining big specimens are protected by law. Rather interestingly this plant has a great way of stopping epiphytic plants (such as ferns and lichens) from growing on it's branches and weighting them down- the tree constantly sheds bark! Below is a picture of Agathis palmerstonii which is even rarer in UK cultivation than A. australis!

Sorry, probably not all that hardy, although is surviving in sheltered places. It is quite tricky to grow to be saleable in pots, so expect prices to be.... discouraging!

WOLLEMIA There's no real point in me going into any major detail about the Wollemi Pine. However, I do find it rather encouraging that a plant believed to have been extinct for millions of years can be discovered by a group of people out walking just 200km from a major centre of population! Makes you wonder what else is out there undiscovered.... Discovered in 1994 by David Noble, the Wollemi is proving to be a tough tree. It is suitable for cultivation as a houseplant, will take pruning to keep it's size down, and is being tested for hardiness- Kew Gardens have at least one, and the RHS garden at Harlow Carr in Yorkshire is growing one outside, so fingers crossed. In the UK the plant is protected by PBRs (Plant Breeder's Rights) and is rather expensive. However, expect affordable trees on the market in the next few years. For more information see www.wollemipine.com/

CALLITRIS I only recently came across Callitris rhomboidea in a Cornish nursery. In the wild this grows (in Australia) to be a smallish tree to about 6m, and even has a cultivar called 'Golden Zero' which is golden yellow all year round. I was rather suprised to find that C. rhomboidea appears in the RHS A-Z, with a picture, and some quite useful information. It is an ideal tree for a coastal garden, tolerating salt and wind, and it is also happy in a free draining and poor soil. The RHS claim it is half hardy (to -5deg C), so best in the South West, but as it is a good coastal tree it may be useful in coastal gardens further north.

I was quite suprised to come across a rather nice specimen of Callitris oblonga at the RHS garden at Rosemoor. Tucked away in a sheltered spot I doubt many people notice it!

Callitris oblonga in all it's glory- I don't know how long it's been here, or how big it will grow in the UK.

Callitris oblonga (branch detail)- this silvery wiry growth seems typical of Callitris, based on my observations of C. oblonga and C. rhomboidea.

ATHROTAXIS This one I like! I've seen a few plants of Athrotaxis laxifolia in the South West, and certain sources suggest it MAY prove hardy further north. Typically seen as a large shrub, the leaves are tiny scales around the stem, giving a rather unusual effect! If you want the rarest of the rare, A. selaginoides (below) has to be the one for you!

Photo courtesy of Jim Stephens. The other species of Athrotaxis is A. cupressoides, which is very similar to A. laxifolia, although the stems I've seen are thinner. The main way to tell them apart is by touch- A. laxifolia is quite rough whereas A. cupressoides is smoother (hence it's common name 'Smooth Tasmanian Cedar).

Athrotaxis cupressoides- easily identified by it's smooth, slightly thinner stems.

Athrotaxis laxifolia- slightly smoother than A. selaginoides, and seems to be green whereas the latter has a blue tint. In the wild A. selaginoides grows quite a bit bigger than the other two species, but I couldn't say if that would apply in the UK. My 'Encyclopedia of Australian Plants' puts the ultimate heights at "6-20m", "8-20m" and "15-40m" respectively.

TAIWANIA CRYPTOMERIOIDES Again, not the hardiest of all trees. This one was photographed at the Abbotsbury Sub-tropical Garden in Dorset. Initially I thought this was Araucaria heterophylla (see above), but this tree is far more bristly. Anyone who knows Cryptomeria japonica (the Japanese Ceder) can see where the 'cryptomerioides' bit comes from! A nice tree, and this one was not too big although I have no idea how old it is.

(The yellowing on the branches is sunlight!) This probably quite young tree is distinctive with it's open branch structure. Very nice thing for a mild garden- not showy but obscure! According to The Gymnosperm Database (www.conifers.org/) this tree is from China and Northern Burma, is found with Chamaecyparis in high altitude forest, and the wood is useful! Look it up for more info....

PODOCARPUS This genus is very diverse, bringing the gardener large trees and smaller shrubs. Of the large trees my favorite must be P. salignus; known as the 'Willow Podocarp' this large mound forming tree native to Chile has long leaves on pendulous branches, giving a mature tree a soft and gentle look. Similar is P. macrophyllus- this differs in having shorter and wider leaves, and generally makes a more rigid shrubby tree. There are questions of hardiness for both of these species, but if you can get hold of a plant of them (particularly P. salignus) they would be worth trying in a sheltered garden.

Podocarpus salignus- this plant has been trimmed hard to provide material for cuttings, so is slightly more compact than usual.

When it comes to the shrubby half of the genus there can be no question of hardiness- these mountain species from New Zealand will take all the cold they can get in the UK (although some gardening books are less optimistic about cold tolerance). In fact one of the appealing features of the shrubby species must be that many turn attractive colours during winter, often turning a rusty colour, khaki greens and browns, and even the nearly white 'Kilworth Cream'! Forms are selected for their winter colour or the colour of their new growth, and sometimes both! My favorite form for new growth is P. lawrencei 'Red Tip', a deep green with red new growth on top- always makes me think of holly leaves and berries... It's a good idea to clip these varieties every so often- it keeps the plant compact and encourages it to produce lots of colourful new growth!

Podocarpus 'Blaze'- note how the seed is nearly seperated from the flesh of the berry; any berry where the seed is not entirely surrounded belongs to a conifer (or Gnetophyte! Wait till I get started on those!).

Female forms produce berries if planted near males, although to be honest this seems a bit hit and miss! This year (2006) has been quite good for fruiting, although I've not seen any Podocarpus fruit like this P. nivalis 'Moffat' (below). Usually you will only get a few berries on a Podocarpus each year, but maybe a very warm summer helps the fruit develop..? Best results are achieved by planting male and females in the same area/border- they would look nice if they were allowed to grow into each other, but were clipped to roughly the same height.

For those of you who like that extra bit of information, Podocarpus give their name to Podocarpaceae, a reasonably diverse group of (I believe) exclusively Southern Hemisphere conifers (including Parasitaxus ustus- the world's only parasitic conifer!). Podocarpus have berries not unlike Taxus (Yew), but whereas Taxus has seeds wrapped by the fruit, in Podocarpus the seed protrudes from the fruit (see picture above). The leaves of the shrubby Podocarpus are short needles, not dissimilar to Taxus.

DACRYDIUM CUPRESSINUM This very rare New Zealand native always reminds me of a 'Weeping Willow' (Salix babylonica). Nice thing, although a little bristly to the touch, with long weeping stems which turn a bronzy colour in winter. Reckoned to be tender, all of the plants of D. cupressinum I know are left out during cold weather, taking occasionally very hard frosts.

This particularly fine example can be seen at Pine Lodge Gardens, St. Austell, Cornwall. www.pine-lodge.co.uk/