All posts by Thor Dalebö


Have a banana!

In 1867 Monsieur Chaté writes, “This species was formerly described in the English, Dutch, and German horticultural journals under the name of C. excelsa. It was named musæfolia by Monsieur Théodore Année, who introduced it into France in 1858, from the resemblance of its leaves to those of the Musa or banana-tree.

This was the earliest reference I have been able to trace to those cannas with banana-like foliage, and it was ‘poshed-up’ with the letter  ‘æ’… how those early botanists tried to show of their educational and intellectual prowess! It raises the question of how we should be spelling it nowadays, as we seem to have a list of possible names to choose from:

    1. Musæfolia
    2. Musaefolia
    3. Musifolia
    4. Musafolia

Looking at the list I think that we can eliminate option 1. immediately, as very few people have keyboards that include the single letter ‘æ’ key.  Option 2. can be eliminated without debate, because what is the letter ‘e’ adding to the simple name depicting ‘banana foliage’?

Now we come to option 3., a popular spelling in the last 20 years or so, although not seen earlier. So what does ‘Musifolia’ mean? I don’t know what a Musi is, or whether my canna foliage resembles it!

This leaves the only sensible option, number 4., Musafolia. The word is made up of two conjoined words ‘Musa‘ (the scientific name of the banana genus) and ‘folia‘ (the Late Latin name for a leaf).

So there we have it, the only logical name for the group of cannas that have leaves resembling those of the Musa Genus is ‘Musafolia’. Needless to say, most people will carry on spelling it how they always have done, but at least I have offered my explanation and reasoning for why it should be spelt ‘Musafolia’



Spring and checking for virus

Back in the 1990’s, before the rapid spread of the canna viruses, we were told by the experts of that time to never judge the health of a canna by the first leaf, as its condition reflects the conditions that it was grown in last year and the way it had been stored over the winter, as it is using stored energy in the rhizome to start growing again.
It will probably also be without a working root system and the new roots will also be ‘fed’ by the rhizome until the first leaves can provide the energy for growth.
A plump, healthy green rhizome, as seen in the photo above, can handle this spring start-up easily, but a poor, dried-up rhizome will struggle, and that will be reflected in that first leaf.
Now we have to contend with virus as well, so those words of wisdom are truer than ever, and I would suggest that a rhizome showing a ‘dodgy’ first leaf should be quarantined immediately, given a dose of liquid fertiliser and kept away from other cannas and vegetables of the tomato family until you are satisfied that the plant is virus free.
If still suspect then destroy it immediately, as there is no known cure.😢😢😢
It is also a sad fact that packets of dry rhizomes nearly always have one of the canna viruses, and should be avoided. Buying a growing plant is always the safest as you can see the state of its health, although acquiring green rhizomes from virus-aware specialist growers carries much less risk.

Polyploidy in Canna

Canna News, reprint of article of Tuesday, 27 November 2007

Polyploidy in Canna

Each cell of a canna plant naturally has 18 chromosomes, or 9 pairs. These plants with their paired chromosomes are termed diploid, from the Greek word for “double”.
The pollen and ovules, are formed through a process called meiosis, which results in the production of cells that have only half the parent organism’s chromosomal material; these cells are termed haploid, from the Greek word for “half”. The haploid pollen and ovule join in fertilisation to form the new diploid cell that eventually becomes the offspring organism, and jointly provide the 18 chromosomes.
CannaPresident’, a triploid cultivar

Sometimes, however, the process of meiosis fails, and pollen or ovules are produced that have the full complement of parental chromosomes; this type of cell is called a non-reduced gamete. When such a reproductive cell participates in fertilisation with a haploid cell, an event that does not occur as easily as normal fertilisation, the resulting offspring has three sets of chromosomes instead of the normal two and is termed triploid. When both pollen cell and ovule cell have the diploid chromosome number, the offspring has four sets and is termed tetraploid. All organisms with more than the normal number of chromosomes are collectively called polyploid.

Polyploid cannas tend to be larger, stronger, more substantial, and more persistent in every respect. This has obvious advantages in any growing context.

The offspring of a triploid and a diploid parent is a tetraploid. Such a cross usually produces few or no normal seeds. With their 27 chromosomes, diploid cannas are difficult to cross with other cannas.

Although in other plants it has been possible to create cultivars with a higher chromosome level, the tetraploid seems to be the limit of the Canna, even after extensive laboratory experiments. Tetraploids can occur naturally as the resulting failure of meiosis, as described for triploids, if there are irregularities in the formation of both parent’s reproductive cells. They can also be produced vegetatively under laboratory conditions.


Origin and Evolution of Cultivated Cannas, T.N. Khoshoo and I. Guha (Neé Mukherjee)




Reprint of Canna News article dated FRIDAY, 30 NOVEMBER 2007
Authors comment: “And it has no long term effects?”


Extract from a paper by L.L. Bruner, G.J. Keever and C.H. Gilliam, Auburn University

The rather dramatic size of canna lilies makes them difficult to manage in nursery and retail settings. Canna lily species and cultivars are characterized by heights of up to five feet with leaves two feet in length and six inches in width. They bloom in mid- to late summer. Problems arise during container production due to their rapid and top-heavy growth habit. Pots blow over easily and shipping costs are increased. Plant growth regulators (PGRs) are effective in suppressing height in numerous species and may offer benefits in the production, shipping, and marketing of canna lilies. The objective of this study was to determine the effects of several rates of four PGRs on height and flowering of canna lily.

Canna lilies were divided and repotted in a substrate consisting of 7:1 pine bark to sand medium amended with 10.7 kilograms Polyon 22-4-14, 0.9 kilograms Micromax, and 3.0 kilograms limestone per cubic meter. Plants were placed in full sun with overhead irrigation. After the plants were measured the following PGRs were applied as foliar sprays: B-Nine, Bonzi, Cutless, and Pistill.

Results of this experiment show that vegetative and inflorescence height of canna lilies can be significantly reduced during production using Bonzi or Cutless. Height suppression was more persistent with Cutless than with Bonzi; however, plants treated with either PGR and transplanted into the landscape outgrew treatment effects within two months of planting.

CannaFrökenThor Dalebö.

Canna (Miniature Group) ‘Froken’, if subjected to the above chemicals we would never find it!

Why more aquatic cultivars?

Reprint of article Thursday, 11 November 2010 in Canna News by Thor Dalebø

CannaEndeavourThor Dalebö.

About seven years ago I built a small pond in the garden, its dimensions are about 2 metres by 1 metre. Not very large, but in keeping with the size of the garden. This is typical of garden ponds in the UK, somewhere for a couple of fish, a small fountain, a few aquatic plants, especially a water lily, and the inevitable frogs.

Naturally, I immediately planted the Longwood series of aquatic Canna in the special aquatic pots and settled back to enjoy them. True to their reputation they did not fail me as they are true aquatics, flourishing under 15-20cm (approx 6 inches) of water and they grew and they grew. This was their failing for me, they are far too large for a small garden pond. Their height made the pool, which was my pride and joy, look like a small puddle.

CannaErebusThor Dalebö.

The Longwood aquatic cultivars were bred for the large ornamental ponds and lakes of Longwood garden, not for the typical suburban garden puddle. The series consists of Cannas ‘Endeavor’, ‘Ra’, ‘Erebus’ and ‘Taney’. My favourite is probably C. ‘Erebus’, a fine pink specimen, but the intense yellow of C. ‘Ra’ (below right) is always eye-catching, and the unusual apricot/salmon orange colour of C. ‘Taney’ is always interesting and last, but not least, we have C. ‘Endeavor’ (above right), with its attractive bright red flowers.

Canna ‘Ra’ Thor Dalebö.

However, I digress. We had already recreated the earliest Canna species cross, having crossed C. glauca with C. indica. However, instead of obtaining the 2 metre (6’6″) tall C. ‘Annei’, we had obtained seedlings that grew to under 1 metre (3’3″), but with the same glaucous blue, lance shaped foliage. So we decided to see if we could create a series of aquatic cultivars based on these seedlings which all took after the aquatic C, glauca, and more suitable for the small garden pond than the expansive ponds and lakes of Longwood Gardens.

Canna ‘Teme’ Thor Dalebö.

Eventually we ended up with Canna ‘Avon’, a pale yellow speckled with cerise, Canna ‘Severn’, which is a golden yellow with some small red spotting, C. ‘Usk’, that is a distinctive self-coloured burnt-red, C. ‘Wye’, which is pink tinged with canary-yellow, and C. ‘Teme’, the ‘white’ of the series, but really a pleasant self-coloured ivory. Others are still undergoing evaluation, and we are still trying to create the difficult orange one.

Was it worth while? I think so, they look just right and in balance in our small pool, and we find that the glaucous blue, lance shaped foliage that they all share adds the final touch of elegance.
Over the next weeks we will try and post articles on some of these new cultivars.

Canna ‘Rosemond Coles’ name confirmation

Over the decades the various names of this variety have varied in popularity, as it has many synonyms. This week I discovered an old catalogue entry from W.W. Coles, nurseryman from Kokomo in central Indiana. This nursery was the plant originator (a sport of The President) and obviously the name is now confirmed once and for all as CannaRosemond Coles’. This also removes speculation that it was originated by Captain Cole in Australia.
The entry in the Canna Cyclopedia has been updated, but the separate synonym lists will not be updated until after Christmas.

Introducing Canna ‘Avranches’

A new introduction from Thor Dalebo of Cannas de Beslon named ‘Avranches’, a medium sized, green leaved cultivar with interesting orange-red flowers in abundance from early July until the frosts.

Named for the nearest large town, Avranches, this cultivar is an open cross on the Marcelle Sheppard introduced CannaZulu Masquerade’, one of the classic Zulu Series from Mrs Sheppard.