Sassafras mystery...

There are 3 species of the true Sassafras trees. The name has also been used confusingly in a vernacular sense referring to other Genera. Sassafras albidum is native to eastern North America where it forms suckering stands of medium sized trees.

But the two Eastern Asian spp are what this short Blog is concerned with. Sassafras tzumu from China has been grown in the UK for around 100 years but never become established or widely available. The second species Sassafras randaiense was introduced more recently by seed from the Taiwan Forestry Institute and is uncommon in its native habitat in Taiwan and appears on the red data list of trees at risk. Both species are represented at Tregrehan by fast growing trees up to 15m tall. There has never been any issue with damage from cold conditions but they are susceptible to branch break in heavy winds so shelter is ideal. The variably lobed foliage is extremely ornamental and colours in the spring and the autumn. The bark as illustrated here in the images is also attractive when young and also upon maturity. Small clusters of typically yellow Lauraceous flowers occur on naked branches prior to the foliage in late winter. I would definitely recommend planting either species if they become more available

Recently the garden was approached by an Institution in the USA who are going to run some genomic trials to help with fungal disease of other Lauraceae such as the avocado. There may be a chance of discovering some resistance in the Asian Sassafras and it would also be very interesting to discover whether there is a significant genetic difference between the two Asian spp. They are exceedingly difficult to tell apart from morphology and the species delineation as far as I can tell is largely based on Geography. The results will no doubt will be published in due course and we will be able to solve the mystery as to whether the Asian trees are really just one species after all….

Young bark of Sassafras tzumu

Mature bark and foliage of Sassafras randaiense

Foliage of S. tzumu starting to colour in October

Gingers...

I have been prompted to post an article on Gingers after the National Collection holder from Sussex visited the garden recently. Various Hedychium spp. are still performing well in the early autumn and I have chosen two to illustrate here. There hasn’t been much heat to speak of this summer but this orange/yellow H greenii below is looking great at the moment. It is one of the spp. that does appreciate the extra warmth from the west facing brickwork in the walled garden to flower well. It’s not much use in the shade of the woodland under all the trees.

The other image below is of a relatively new sp called Hedychium viridibracteatum from karst limestone in NE Vietnam. It has a distinctive spidery, white flower which gives off a lovely delicate fragrance. This is a welcome addition in the greenhouse flowering so late in the season. It was collected by Crug Farm from relatively low elevation so will stay inside until we can divide the clump and try outside in due course.

Champion Stick

Dr Owen Johnson has been updating the tree measurements in the garden over the past few days. He is recording data from all the potential champion trees for the Tree Register of the British Isles; TROBI. This involves taking height and girth measurements for 100’s of different specimens in the garden, from 2m in height to over 45m. The TROBI website is online and I encourage everyone to join this charity which allows access to the database of all trees of exceptional size in the UK. He is spending a couple of weeks in Cornwall updating many of the region’s tender and rarer trees.

While measuring this oak tree from Yunnan Province China on Monday in rather damp conditions, we suddenly realised that we had been photo bombed by a stick insect. There are no native sticks in the UK but in warmer sheltered areas of Cornwall there are populations which have built up over the past 100 years or so. There is a hedge in Par which is stacked full of New Zealand insects so the locals say. Their legs are very delicate and they should be left alone if encountered. This stick on the label was still hanging in there a few days after we first saw it…..

Rhododendron Time

The Rhodo time of the year is full on for the next week or so. Many of the scented Maddenia Section plants will be at their peak and with the bluebells, azaleas and some welcome sun the garden is looking great. This 1st image is a plant that was seed grown from NE Vietnam. Very early for this group which includes, liliiflorum, nuttallii and excellens it is a remarkable sight absolutely smothered in flowers. The 2nd image is of a hybrid, nuttallii x edgeworthii bred by my father Mike Hudson in NZ. Its very attractive keeping the bullate foliage of the Rh. edgeworthii and the large scented flowers of the Rh. nuttallii. There are many others dotted around in the woodland, many of which are perched on old rotting logs and stumps where they can emulate their natural position in their native habitat.

Save the Pot

Over the past couple of weeks we have been clearing out the prop house and potting things on. There are always a heap of pots where there hasn’t been any germination and moss and liverwort normally take over the surface making any germination of small seeds virtually impossible. Luckily most smaller seeds get away fairly quickly when sown so if nothing is showing the pot is ditched.

Other larger seeds we have to make a call as to how long its worthwhile keeping. With plants such as Melliodendron, Perkinsiodendron, and in this image Rehderodendron it can often take several years to break down the hard seed endocarp allowing moisture to penetrate and bring the embryo to life. This emerging seedling in the attached photo has finally emerged after 6 1/2 years which i think is the longest time yet. Breaking the dormancy on these woody kernels can be interesting. Rotary mower run over Davidia has been known to work as has putting Melliodendron into a vice until cracking also seems to speed the job up…..

The Sun

Suddenly the sun appeared in the midst of a very dreary Spring and with it these two plants lit up the corner of the walled garden. Sophora cassioides looks as if it should be from New Zealand but in fact it comes from Chile. Very similar once mature this Chilean species doesn’t have a juvenile phase unlike S. microphylla from NZ which is presumably due to a lack of giant flightless Moa birds to mow the foliage in South America. It flowers early in the season as can be seen here on a young plant.

Growing above this is a recently introduced form of Clematis armandii var hefengensis from China. This variety was given to me by Chris Sanders who wasn’t sure that it was hardy. I planted it on the walled garden under a large camellia which it has vigorously started to monster covering the bush in only a few years. It has proved perfectly hardy and is worth growing when compared to the type with its more numerous and larger petalled flower with lovely dark staining to the underside .

Christmas 2023

This image was taken a couple of weeks ago when we had a few centimetres of snow one morning. The Cathaya argyrophylla looked spectacular and very Christmas like for a few hours until the snow started to melt after lunch. In fact the predicted temperature for the 25th of December looks as if it will be in double figures Centigrade this year, so very mild for us here in Cornwall.

I first planted a couple of Cathaya trees here out in the woodland about 20 years ago and the roe deer bucks immediately knew a new, tasty, and critically endangered tree to completely wreck, which they proceeded to do. So after that initial debacle I planted the next two trees in and around the walled garden closer to the house. These trees have done well and are now around 4-5 metres tall with foliage to the ground, very ornamental plants even with no snow attached….

Merry Christmas everyone and the very best for 2024 from all of us at Tregrehan; we look forward to welcoming you again, (if you can make it), when the garden opens again in Mid March.

Quercus insignis

At last we seem to have been able to keep a Quercus insignis alive in the garden for about 5 years now. Numerous trees have been tried in different places in the woodland and been knocked back by the winter every time. There were just two plants left nearly 4 metres tall about 50 metres apart and last winter nailed one right back to a few twigs but this one looks terrific and is shooting away with chocolate/purple coloured young foliage up to 30cm long this spring as can be seen here.

I have just received a couple more seedlings which after growing on for a few years inside will be ready to plant next to this one as it looks as if we have found the spot to give them the best chance of survival. The acorns are spectacular being several inches in diameter and shaped rather like flying saucers. It would be amazing if one day one of these subtropical Mexican trees would oblige and produce fruits in Cornwall……

Dendroseris litoralis

This fulla is providing some full on action in the greenhouse at the moment. A couple of small plants were given to me by a friend who gardens in a very mild situation in Mousehole in West Cornwall. The huge leaves look as if the plant has strayed out of a field of overgrown brassicas whereas it couldn’t be further from home. It is in fact native to Robinson Crusoe Island off the west coast of Chile where the dreaded goats are scoffing it into an endangered and rare item.

This small tree can also be found under the name Sonchus brassicifolius, which is part of the daisy family, Asteraceae. As can be seen in the image attached the wildly orange hanging flowers are in complete contrast to the foliage. Seemed to be easy to grow in the greenhouse, once it was up and away from the molluscs, that is. Plenty more buds to open for visitors to see when the garden is open on Wednesday afternoons.

Honeysuckle time

Lonicera spp. calcarata; subequale; hildebrandiana

With this sunny Summer weather and long days at this time of the year the Lonicera spp have been looking spectacular around the walled garden. A large genus with the three plants here showing some of the range in the flowering and habit that they are capable of.

The first one, (calcarata), is a strong growing climber from Sichuan in China. It is growing over a camellia next to the garden wall as can be seen in the image here but Mikinori Ogisu who introduced this plant advises giving it a large tree to scramble into. He has seen it in its natural habitat at least twenty metres high when given enough light next in marginal forested areas.

The second, (subequale), also originated from a Ogisu collection in China. Much less vigorous than the previous sp. the flower bunches emerge from a curious hat like protective lid. Ogisu says that this plant is most often seen in wetter areas in the natural forests where it perches epiphytically in the canopy trees.

The third, (hildebrandiana), known as the giant Burmese honeysuckle has been in cultivation for well over a hundred years. It is rather more tender than the previous two plants and this image was taken in the greenhouse where the scent fills the whole area. The spectacular yellow and white flowers are the largest of the genus and continue appearing all Summer.

Rare Plant Fair 2023

Its looking all set fair for The Fair this weekend. Traders are all raring to go and hopefully everyone with chlorophyll filled veins will be here and fevered up as well. The garden is also still full of late spring interest and the flowers have held on as the nights have been on the cool side and with no wind to speak of. This is a phone shot from the house roof where we have been completing some work in this fine spell. White Pearl is still full out, echiums are on the move and the conifers; C. macrocarpa and P. totara have flushed out with soft young growth.

The garden will now be open on Wednesday afternoons until the end of October for season ticket holders, visitors and holiday makers alike. There is much colour brewing in the walled garden borders, in the glasshouse and amongst the climbers on the walls. A special entry price of £5.00 pp (Cash only) for this Sunday while the plant fair is on. We look forward to catching you soon….

Xeronema callistemon

Well we have finally done it, a big day after a long wait!

The top image here shows the plant of Xeronema in the glasshouse which has just produced a single flower bud. About 25 years ago we put this plant into a rubbish bin and dug a deep hole in the ground and buried the whole container. This was done to eventually constrict the root system enough after many years of root growth to mimic its natural growing situation in the wild. Xeronema is endemic to a couple of small islands off the North island of NZ where it grows on and in crevices of cliffs. There is very little soil there and the roots fight there way into the rock to gain a hold and find skerricks of moisture. We have been waiting this long without any sign of a flower until now.

In Auckland a few years ago I saw this plant in the lower image below growing out of an old clay tile drain. This neatly shows what we should have probably done in the first place to speed the flowering up a bit. The plant looks more than happy squeezed into the pipe and is flowering its head off! Mind you we hope that now that our one has fired up the numbers of blooms will increase every year; here’s hoping….

Rhododendron sinogrande seedling

There is a huge plant of Rhododendron sinogrande growing not far from the house near the dog statue. Unfortunately this tree doesn’t have any background as to where it came from originally, but it is all of 10 metres plus which must make it a fair age, certainly pre war. The flowers are still the largest of any in the garden which is remarkable on such an elderly tree.

A result of the spread of the canopy is that there is quite an area of shady mossy ground underneath where occasional seedlings emerge. There was one such plant about 15 years ago which I left as there was enough space for it to develop and not interfere with the parent. I was in the garden with a friend last year and noticed these interesting pink buds opening on the top half of the bush and was passing yesterday when I spotted these blooms much lower down at eye level. It is quite a sight and colour shade for this species. I’m guessing that it has played away with something nearby with some pink in its parentage. Maybe even Rh. Elsae which is nearby and was bred in the garden by Jovey Carlyon in the late 19th Century. This hybrid was supposedly half hodgsonii making it a possible candidate for imparting the colour into this seedling. It is well worth its place and also layering several of its lower branches to eventually move into more open situations.

Dimorphanthera sp.

This arresting bunch of flowers has just arrived for the first time in the glasshouse. It is a Dimorphanthera and belongs to the Ericaceae family. As can be seen in the image it is scrambling around using the sloping roof section as a support. Often in the wild these plants are seen as scandent lianas and use other more twiggy bushes such as vacciniums and small rhodos a metre or two tall to run around in. Originating from Equatorial zones such as Papua Guinea in Malesia, where they can appear at over 3000m elevation none are hardy in our climatic zone unfortunately, being able to withstand light frosts for short periods only.

There are several good collections of these ornamental plants where there are fine collections of rhododendrons as well. Namely Pukeiti in NZ, The Rhododendron Species Foundation in Seattle and the RBG in Edinburgh. I’m not sure which species it is yet but have sent a message to Steve Hootman at the RSF who knows a fair bit about these fellas for an ID…. These plants are great for a cold greenhouse, its such a pity we cant include the nectar feeding iridescent birds in this display for some pollination action as well!

Donation

Nothing really to add to this crazy image of Camellia Donation here at its finest in early spring. The plant isn’t attached to the house at all but I do rest a long ladder against it every couple of years and cut it back tight against the wall to prevent it bowing over in the wind and breaking up. Even so it looks as if the branches at the top of the camellia are just floating about and not even connected to the bush itself. What a sight against a blue sky. The season is well underway now….. and the garden opens for 2023 tomorrow.

Wed, Thurs, Fri and Sundays from now till the end of May. Lets hope that we get plenty more views like this on the open days, and some more rain in between. Daily entry is £10.00 per adult with children free and seasons tickets are available from the garden entrance too for just £25.00 pp.

Winter Orange Action

We were recently tidying up winter sticks and rubbish in the Chilean part of the garden when I noticed these two plants with stunning orange fruits. The first image is Luzuriaga radicans which loves to creep around in shady places on the ground but really excels when given a tree fern to climb or this soft redwood bark. It has reached a couple of metres in various places and the fruits are fairly persistant giving a good show into the winter. It really needs to climb to show off its attractive starry white flowers and subsequent fruits.

The second image is Myrceugenia chrysocarpa which was collected by Peter Cox in Chile. This genus belongs to the Myrtaceae so presumably the fruits are edible, (I haven’t tried) but maybe they don’t taste very sweet as there are still plenty on the small 2m bush right through the winter again, the birds haven’t touched them. Both fruits are remarkably similar in colour which is curious, maybe there is an animal in South America that spots these from a long way off and aids the seed dispersal?

Trachycarpus geminisectus

I wasn’t sure what would be the first post of 2023 but I have just been asked for an image or two of this recently introduced palm for The Palm Journal, so this palm it is first up for the Tregrehan Blog as well. The individuals in the image below have been growing here for only 10 years or so and have been comfortable with lows of -6 degrees. As can be seen from the group they are very ornamental with striking silver backed leaves and hairy trunks. The species was only brought to scientific attention in 2003 and named geminisectus due to the twinning of the divided leaf section tips, quite cool really!

Interestingly their natural habitat is very bony limestone rocky terrain in Nth Vietnam. Not much of that particular terrior in Cornwall, but they have adapted to the conditions here remarkably well. Two of them have been flowering and setting seed here for the past few years which is exciting. Having become adapted to thin poor soil they manage to reproduce at only a few feet tall unlike most other Trachycarpus which are mature at a much greater height. So quite useful for people with limited space who wish to grow a small palm. The species has clung on in the wild due to the relict flora being of an open sunny situation. The usual wide range of warm temperate evergreen broadleaved trees hasn’t been able to colonise and speciate within these isolated karst peaks and swamp out the marginal loving trees and palms with heavy shade.

Talauma hodgsonii

This is second time lucky for this plant outside. I did initially put it out about three years ago. It was looking well tucked under an old Tsuga dumosa. Unfortunately during that winter it was flattened by a falling limb and so it had to spend the next few years recuperating inside the glasshouse. It has responding well to a heavy haircut and has shot back up again as can be seen in this image. Its taxonomic background is quite complicated as most of its relatives grow in Central America and the Genus is accepted now by many botanists to be Magnolia rather than Talauma.

It was collected by Keith Rushforth in Arunachal Pradesh from evergreen forest at only medium altitudes. It will be tender looking at the accompanying flora but with some size to the trunk now I am hoping that if it does suffer in the winter there will be enough root and stem energy to spark it up again next season. JD Hooker first named this plant after his travels in Sikkim in the 1850’s. He describes the flower as having a strong scent with purplish outa tepals surrounding a row of pure white inner tepals, well we are definitely looking forward to that one day!

Araliad Action

The garden is open now on Wednesday afternoons until the end of October. There are a still quite a few interesting plants for sale including this selection of Araliads. Good stocks of Sinopanax formosana and Fatsia polycarpa “Megafatsia” in 2.5l pots, and also Brassaiopsis bodinieri and hispida in 5l pots. There is a 20% discount on marked prices of these if two or more are purchased together. It will save us the trouble of potting them on for next season! I’m afraid that we don’t deliver so pick up at the nursery is essential, if anyone has trouble making Wednesday afternoons then please contact through the website for arranging another time.

Now with cooler nights looming and crispy days there will be a reasonable chance of some Autumn colour in a few weeks time so a visit will be well worthwhile. There are lots of interesting fruits in the walled garden and in the glasshouses. Most things have picked up after the dry Summer although the soil moisture levels are still way down making digging planting holes hard work.

Lapageria rosea var. alba

The old Lapageria climbers in the greenhouse are beginning to really show off. They have loved the warm temperatures over the Summer, and with plenty of moisture from frequent watering several plants have produced large bunches of flowers as in the image here. They have been cultivated at Tregrehan inside and on east facing walls outside where they never dry out, for well over 100 years. These old plants can get a bit tatty and moth eaten though and when this occurs they are brutally cut to the base. This tip was passed on to me by someone who had observed this pruning method accidently carried out on some Lapageria plants under glass at Chatsworth. The resulting vigorous clean regrowth was outstanding and I can definitely vouch for the results having used this method and seen the subsequent large flowering bunches..

Over the next couple of months they will be one of the chief highlights of the walled garden here. A few more varieties have been added to the collection over the last twenty years and as well as red, white and pink varieties there are now picotee and spotted flowered selections growing. Patience is the key and it can take many years for a plant to really feel at home and start to produce the stiff, (but slug prone), strong shoots from below ground level. They love plenty of feed and a deep layer of mulch around the base is also key to successful cultivation.