Second Seedling Surprise!

Three weeks later than planned, I have finally weeded and redressed the raised beds with Strulch, but only after lifting and potting-up 138 self-sown seedlings! I started labelling them to reference the location I found them, but soon realised this was futile as the parentage was indeterminate given that there were over 40 species and cultivars for the pollinators to visit in a relatively confined area, promoting their promiscuity and ability to cross with almost all and any of them.

However, according to ES Anderson, the botanist after whom the Andersoniana Group is named, this is how most of the hybrid selections were created, by open pollination in domestic gardens. There are rarely such a number of species and cultivars in close proximity so it is unlikely to happen in most domestic settings but, in my garden, the chances of nature producing a new hybrid are high, very high in fact. So, I will grow these 138 babies until they mature and flower, probably next year, and see if there is anything special to select and possibly introduce to the market after further trials.

Of course, there could be nothing new, nothing of any merit, nothing to reward me for the months of time spent, compost used, watering, feeding and molly-coddling. But then again, the next big thing could be in one of those pots!

These are just the self sown seedlings out of the Strulch mulched beds. The Strulch, I have found, doesn’t last the two years stated in the marketing hype, it is almost gone after a year. But it did a very good job of preventing most weed seeds from germinating, maintaining a moist soil beneath, deterring slugs and molluscs and providing an attractive dressing for the raised beds. So, £75 well spent in my opinion.

The next job is to locate and remove the self-sown seedlings in the pots, as these too are unlikely to be the same as the parent plant which produced the seed. If left in the pot, their roots will become tangled with the main plant and be difficult to remove. Best to get them out now as seedlings and maintain the integrity of the parent. In all likelihood, the parents will be the adjoining cultivars, but not necessarily. Better to separate them now, grow them on and see if there is a worthy new hybrid next year.

Seedling Surprise

The promiscuity and prolific self-seeding of hardy Tradescantias is well known and is the reason for so many open pollinated hybrids being discovered and in such a diverse range of colours and leaf forms. I suspected it was going to be a potential problem for me at some point and here it is! Just two years into this venture, this is obviously going to be an ongoing problem but one which may have as many benefits as disbenefits.

I have said in an earlier post that the open soil areas surrounding the 20 litre sunken pots are covered in Strulch mineralised straw mulch which reduces weed seed germination by blocking out light and deters slugs and snails who can’t slither over it. However, the Strulch gradually rots down and I think an additional 30-50mm is going to be required annually to top it up and stop the falling seeds from germinating.

The other, and possibly more worrying aspect of this problem, is when seedlings pop up in the pots themselves because this is potentially a new/different hybrid to the plant in the pot and if allowed to grow will become entangled with the roots of the main plant.

However, the upside to all this is the opportunity it presents for identifying possible new hybrids which could be worthy of further cultivation if sufficiently robust and different. The big drawback is the uncertainty of parentage as with 50 plants in close proximity, open pollination could occur between any of them.

Nobody said this was going to be easy!

First to flower!

It may be a fluke, but the first Tradescantia to flower is ‘Little Doll’, but not the parent plant, one of the divisions I took a month ago on 26th March.

Perhaps the act of division caused a reaction which in turn promoted flowering a month earlier than expected. Perhaps the additional warmth and protection of a cold greenhouse brought it on compared to the parent outside and exposed to the current warm days and cold nights.

Whatever the reason or the cause, it is a joy to see the first flowers and the promise of a thousand more to come!

Annoying!

I am increasingly irritated by plant nurseries who send valuable, and often expensive plants riddled with weeds, particularly Hairy Bittercress which seems to prevail no matter how many times you weed it out! This example of Tradescantia (Andersoniana Group) ‘Lucky Charm’ from a nursery in Essex is just one example of many I have received over the last two years and is how weeds get introduced into gardens. You innocently plant out your new treasure only to find it swamped with weeds a few weeks later.

Coming as I do from a Sales & Marketing background, I feel this is akin to any other product which is not fit for purpose and lacks any degree of quality control. It is widely accepted as ‘inevitable’ but I know one or two nursery owners who think as I do and would never knowingly sell plants in this condition. Yes, it takes time, trouble and effort to keep plants clean and free of weeds, but surely they have a duty to at least try. Otherwise, they are falling short of their responsibilities to their customers.

Or, is it me?!

Propagation

It is Saturday 26th March, the garden is full of Spring bulbs and blossom but, in a curious tradition only we could make up, the clocks go forward an hour tonight and British Summer Time (BST) begins! This means two things, it’s time to plant out Sweet Peas, and time to start propagating the Tradescantias.

By propagating, I really mean dividing or, more accurately, removing a slice from the outer part of the clump. This is the second year of the Collection and I am under an obligation from Plant Heritage to hold not only a main listed plant (an Accession), but also two others of each cultivar. This is known, as in Royal parlance, as an ‘heir and a spare’ (think Princes William & Harry!). It is an insurance policy to ensure the survival of each cultivar by always having a duplicate plant in case one perishes.

In this example, I am going to take a division of Tradescantia (Andersoniana Group) ‘Charlotte’ which is looking very happy, healthy and raring to go. The process I am using leaves 80% of the plant untouched and unharmed, thereby giving it the best possible chance of recovering quickly and growth unchecked.

A small outer section is selected and the hand trowel inserted smartly and vertically, ignoring the loud graunching noise as it cuts through the crown and thick fleshy roots. This can be a little disconcerting and it is only natural to think that irreparable harm is being done but, like other fleshy rooted perennials (Agapanthus, Rudbeckia, Sanguisorba etc.), the plant is programmed to accept the damage as part of life and recovers quickly.

The resulting division is lifted cleanly away from it’s parent and moved to the bench.

This one small piece could easily be divided into four or even six separate small plants, but I am just looking at two for my purposes. If I was propagating to increase stock for sale, as a nursery would, I would be pairing this division down into as many small individual plants as I could and would probably have taken a much larger division to start with, depending on the size of the clump.

Using an old breadknife, I cut the division into half, slicing clean through the roots and crown of the plant.

The mass of roots can clearly be seen in this picture but, remarkably, the plant will hardly notice and has enough growth material intact to carry on and produce new shoots and possibly even flower this year.

This size of division fits neatly into a 1 litre (12.5cm / 5″) pot with plenty of room for a season’s growth. Obviously, smaller divisions would only require a smaller (9cm / 3″ pot).

I pretty much use Melcourt SylvaGrow, peat free compost for all my propagation which includes seed sowing, cuttings, divisions and potting on. I have tried many, many alternatives but keep going back to Melcourt. I occasionally add a pelleted slow release fertilizer if the subject is likely to put on fast growth and requires additional long term nutrient, and sometimes add 20% John Innes or bagged topsoil if I think more ‘body’ is necessary, but I mainly use it straight out of the bag with excellent results.

I find the blend of fine bark, coir and wood fibre is good at retaining water and nutrients, is consistent and, importantly to me, contains no peat or recycled green waste. There is a similar Melcourt product with added John Innes but I find it more convenient (and less expensive!) to add my own in the ratio I want. There is enough base fertilizer to see the plant through the first 6-8 weeks, after which additional liquid feeds are required.

The compost is perfect for a job like this, clean and easily handled, needs not pressure, just tap the pot on the bench to settle the material around the roots, water, label and finish.

The parent plant is simply backfilled with soil and mulched to fill the gaping hole left by the division but in a week or two, the tremendous growth rate of the plant will completely mask the removal.

I will diarise a photo in 2, 4 and 8 weeks to demonstrate the recovery of the parent and growth of the divisions.

Hybrid Origins?

Tradescantia (Andersoniana Group) ‘Innocence’

I am sure this will be resolved over the coming weeks and months, but at the moment I am very confused about the origins and status of the Andersoniana Group hybrids. It seems pretty clear from all the research I have read that the parentage of most of the original hybrids were Tradescantia virginiana, Tradescantia ohiensis and Tradescantia subaspera. However, it is also true that Anderson himself found very few hybrids in the wild because although these three species share overlapping ranges, they enjoy differing habitats, therefore rarely coming into contact.

So, this led Anderson to speculate that it was only when two or more of these species were grown together in close proximity that hybrids began to appear through cross pollination. Tradescantia was certainly one of the first plants to be introduced into Europe from North America by John Tradescant the Younger in 1629, some 120 years before Carl Linnaeus even named the plant Tradescantia virginiana in Species Plantarum in 1753, certainly long enough for multiple hybrids to appear in domestic and botanic gardens in the UK and on the continent of Europe. However, Anderson then went further and showed through gene and cell research that these hybrids also crossed back with one or more of their parents creating ‘interspecific hybrids’.

Over the last 200 years, hybrids worthy of cultivation have been selected, propagated vegetatively, and, until recently, were known by the name Tradescantia × andersoniana. Further deliberate crossing and back-crossing has subsequently produced huge variations in flower colour and size, leaf colour and form, height, vigour and flowering period. Of course, naturally occurring hybrids are still being discovered and selected, and I think it is probably true to say that what we now call Tradescantia Andersoniana Group is a mixture of both.

Tradescantia virginiana ‘Brevicaulis’

I am indebted to Jorge of blog.primrose.co.uk
for the following detail which explains the origins and
differences between Species, Variety and Cultivar.

What is a species? One definition states a species is a group of
similar individuals which can
reproduce successfully with each other
while at the same time being reproductively isolated from other similar
species. This definition leaves it up to scientists to decide when a group of
individuals is distinct with some placing greater weight on genetics, others
more obvious characteristics such as their morphology.

When a group of individuals becomes geographically isolated, it will
begin to develop unique traits, making it distinct from the rest of the
species. These distinct groups are known as varieties. Over time, they may
become so different from the parent group that they are unable to breed,
leading to the creation of a new species. Often, however, a variety comes into
contact with its
parent group, resulting in an influx of genes that
erodes their distinct features, reintegrating it into the greater species
group.

Varieties are true to type as their seeds produce offspring with the
same unique characteristics of the parent plant. Cultivars are distinct from
varieties in that they do not occur naturally in the wild. Cultivars are selected
by humans for specific characteristics and are propagated through vegetative
cuttings i.e. cloning. Propagation by seed will often lead to something
different from the parent plant and as such they aren’t true to type”.

Synonyms

Tradescantia (Andersoniana Group) ‘Carmine Glow’ or ‘Karminglut’?

Synonyms are a really BIG problem for gardeners in general and National Collection Holders in particular. When a plant becomes popular and sales increase, it usually isn’t long before a commercial plant nursery offers an extremely similar plant for sale under a different name. There might be a tiny difference in flower or leaf colour or no difference at all! They want more sales and if people are buying a particular plant they will also buy ones which are very similar, thinking they are getting something new and different. Collection Holders like myself might hunt down a plant with a name they don’t recognise only to find it is something else they already have but under a different name. This is very frustrating and can be time consuming and sometimes expensive. I would normally advise people only to buy from reputable sources but they are often the biggest culprits!

It seems to me that because Tradescantias are so promiscuous, and produce cross pollinated seedlings at the drop of a hat, this is why there are so many different hybrids, many of which are only subtly different to each other. On any given plant, not all the flowers will be identical, so are the two flowers featured above from the same plant or differently named plants? They are accepted by the RHS as different plants, ‘Pauline’ and ‘Pink Chablis’, but at several points last year both plants looked identical. The flowers seem to have stronger or weaker flower colours depending if they are grown in sunny or partly shaded positions, and colours seem to weaken as the flowering period comes to an end. Of course, there are many other differences and variations which characterise specific plants, not just flower colour, but these are often very subtle indeed!

A former Tradescantia National Collection Holder, Hazel Kaye, recently told me that she purchased a Tradescantia Andersoniana Group plant named ‘Bridesmaid’ at a plant sale in Leicester and believed she may have found something new. It turned out to be a self sown seedling from a local garden which the owner had named herself and which had not been trialled or tested before offering it for sale. It was a poor selection and not worth pursuing.

Tradescantia ozarkana – a species widely distributed in Missouri, Arkansas, and Oklahoma, USA

I am indebted to the Botany Advisory Services of the RHS who kindly allowed me to quote from their leaflet ‘Guide to Plant Names‘.

“Although the ideal is for each species or cultivar to have only one name, anyone dealing with plants soon comes across a situation where one plant has received two or more names, or two plants have received the same name. In each case, only one name and application, for reasons of precision and stability, can be regarded as correct. Additional names are known as synonyms.

In the past, and in the nineteenth century in particular, when a huge amount of botanical exploration was taking place, it was possible for botanists to be beavering away describing and naming plants in different parts of the world, blissfully unaware that they were duplicating someone else’s work. This is perhaps difficult to understand in these days of instant global communication, but it led to many cases of a single species with two or more names, or two or more species with the same name. The simplest way to resolve the problem of duplicated and superfluous names is to invoke a rule of priority – the earliest name correctly published wins and new names are therefore needed for some plants with later, incorrect names.

This is a basically sound idea but has led to changes of some very familiar, yet incorrect names due to the discovery of earlier, correct ones in very obscure texts. This can have a destabilising effect, contrary to the intention of the rule of priority, so there is now a much more pragmatic view being taken, with some of the more destabilising proposed name changes vetted by an international panel and often rejected if the technically wrong name is widely known. For example, the popular heather, Erica carnea, was saved in this way from being changed to Erica herbacea.

Cultivars acquire extra names in similar ways to wild plants and also through the deliberate re-naming when the original name is felt not to promote good sales! The same principle of priority applies for cultivars as for wild plants so there are always cases where correction is needed. However, it is not always appropriate to provide a new, unique name for a cultivar which has been given the same name as an existing plant. Where there are large groups of cultivars, such as in the genera Fuchsia and Pelargonium, repetition of cultivar names has proved difficult to avoid. In these cases, names can be qualified with the name of the breeder, the date of introduction or the plant type to help pinpoint their identity.

In the case of wild plants, correct identification and naming relies on knowing what species exist and how they are related. Add to this the increasingly reliable evidence of evolutionary trends provided by DNA and molecular studies and the fact that, for better or worse, the naming system aims to reflect the classification and therefore relationships, and it can be seen that some changes are inevitable….genera being split, new ones created, others amalgamated.”

This is a major source of irritation for National Plant Collection Holders as I have already said. In the main picture above, Tradescantia (Andersoniana Group) ‘Carmine Glow’ is the same plant as ‘Karminglut’ (which means Carmine Glow in German) and is recorded as such on the RHS database. However, I have discovered sellers who offer both as distinctive plants.

Likewise, Tradescantia (Andersoniana Group) ‘Sweet Kate’ (above) is a popular variety for sale in the UK due to it’s distinctive yellow foliage and mauve flowers. However, in the United States, I have discovered a virtually identical variety for sale on the internet called ‘Charlotte’s Web’. It remains to be seen if this is indeed the same plant but the images I have observed would suggest so.

As my Tradescantia journey progresses, I will no doubt be discovering many more instances of the same cultivar with different names and my collection will require constant scrutiny to weed out the synonyms.

Pots & Supports

Apart from the plants themselves, the biggest expense so far has been the pots and the supports, but I considered this a one-off cost and was happy to indulge myself by purchasing the best I could find and afford. As it turned out, the best pots were found on Ebay sold buy Oakland Gardens in Kings Lynn, Norfolk. I decided that heavy duty 20 litre rigid black plastic pots were the most suitable and found them for £3.50 each with free postage and packing. As it turned out, the packaging didn’t account for the way they would be thrown about and damaged by the courier but, all credit to Oakland Gardens, they agreed to replace the broken ones immediately.

They must have been thrown about quite violently because these Aeroplas pots are very well made and unlikely to be damaged simply by a bit of rough handling. Of course, the idea was always to sink them up to their rim in raised beds so they had to be able to withstand the sideways pressure without buckling and be strong enough not to split, should the Tradescantias become pot bound and apply pressure from the inside as Agapanthus do.

So why 20 litres? Why not 10 litres or 35 litres? Well, it was partly down to cost and space, but as I would be splitting them regularly, at least every other year, it seemed to make sense not to go too big. Tradescantias are clumpers, producing more and more thick fleshy roots every year and gradually spreading sideways. I felt I had to give them plenty of growing room and enough growing media to satisfy their water and nutrient requirements, but also contain them and keep their roots in one place and under control.

As you can see from the picture of ‘Purewell Giant’ at the top of this page, some of the Tradescantias get quite tall, but without the company of other neighbouring plants they also tend to droop and fall over, often snapping their stems in the process. Plant supports are essential for the taller varieties and I have chosen these simple ‘Grow Through’ 6mm untreated mild steel ones from Plant Supports of Tenbury Wells in Worcestershire. They are 37cm diameter which is wide enough to span the 20 litre pots, and 57cm high on four sturdy legs pushed into the ground which can be raised as the plant grows taller. I purchased 10 for £63.77 including VAT & delivery. That may sound expensive but they will last a lifetime. They are also much more purposeful and attractive than sticks and string!

And, in case anyone is wondering about the mulch, it is chopped up mineralised straw called Strulch. It prevents weeds germinating, keeps the soil or compost moist by reducing dehydration, discourages slugs and snails who don’t like slithering on it, and dresses the soil surface attractively. Lasts for about 2 years, gets absorbed by soil and provides organic content, doesn’t blow about (surprisingly!) and is recommended by the RHS and all good gardens.

Welcome!

Welcome to this website all about Tradescantia virginiana and the Tradescantia Andersoniana Group.

I hope you find the information I provide useful, the photographs inspirational, and the journey interesting. As the newly accredited National Plant Collection Holder, I am on a mission to collect all known cultivars of hardy Tradescantia listed in the RHS Plant Finder over the last 20 years or so, many of which are no longer cultivated by plant nurseries and may prove difficult to find. However, they may still be available from small independent nurseries who do not list plants in Plant Finder, or fellow gardeners who bought plants many years ago and may not realise those particular cultivars are now threatened and could be lost forever.

As well as playing my part in helping to preserve the plants for future generations to enjoy, I will also revel in the detective work, the research and the joy of sharing all this with other interested gardeners. I hope you enjoy it too.

David Simpson

How it all began

The Missing Genera campaign began in 2016 and every year since, Plant Heritage has highlighted ten different varieties of plant not currently represented in a National Plant Collection.

Vicki Cooke, Conservation Manager at Plant Heritage explained: “The idea of the Missing Genera campaign is to showcase some of the many types of garden plant we have in the UK that don’t have a National Plant Collection to look after them. Anyone can help by starting their own National Plant Collection of one of the types listed this year, which they can care for, grow and ultimately help to conserve for future generations to enjoy.”

In July 2020, just as the UK was slowly emerging from a national lockdown caused by the Coronavirus pandemic, Plant Heritage published the list for that year: ArisaemaAubrietaBerberisDaphneElaeagnusGauraHoyaPapaver,  Robinia and Tradescantia.

Tradescantia ohiensis

To be honest, I only had a passing interest in Tradescantia. It was not a genus I had developed any passion for, either in the garden or as houseplants. However, I had recently decided to redevelop my fruit and vegetable garden with ornamentals of some kind and the appeal to start a National Collection struck a chord. When I delved a bit further into the genus, it was clear that the species originating in the mid-west of North America, the winter-hardy species, were easy to grow and propagate with little specialist care required for their wellbeing. So easy, in fact, that they are considered to be an invasive weed in many States and difficult to eradicate!

Desk research on the internet revealed a fascinating history and an extensive range of species and cultivars, cultivation notes and warnings about prolific seeding and spreading habits but, on the whole, it was a genera that interested me and sparked my curiosity. Could I really build up a National Collection? Could I seek out all known cultivars in the UK? At 70, was I too old to begin the task and who would take it on if I became ill or worse?

My fears were unfounded. Initial discussions with the wonderful team of plant conservationists at Plant Heritage HQ in Guildford, and my local Gloucestershire Group committee emboldened me and I took the plunge!

What follows is my account of how I went about building the Collection, the process of becoming accredited and the responsibilities that come with it. It will also document detailed descriptions of each plant in the Collection and as much useful information as I can offer anyone thinking of either growing Tradescantias for pleasure or taking on a National Collection of their own.