Chemicals can be dangerous

Chemicals can be dangerous

The rain was pouring down, but as a true Germanic I knew my duty. My knees were sodden as I knelt down and planted out the collection into this suddenly wet garden, while the rain poured down. After I finished planting out, having added a handful of bonemeal underneath each plant, as a final solution, I went around with pellets of Growmore and scattered them around on the surface.

Chemicals can be dangerous
Chemicals can be dangerous

Next day I went to visit this wet setting and about 10 plants, out of the 150 I had planted, were in a desparate state, having leaves that were bent and which had given up. All tne others had survived the continous rain. So why had the others had their foliage destroyed at the stem?

It took a while to work it out, and all sorts of explanations provided red herrings before the solution. When I threw the Growmore capsules around, some had lodged in the joint between the stem and the leaf. Careless distribution, because Growmore has to be on the ground to have the effect it is used for.

As soon as the 20 hours of continous rain arrived the Growmore pellets lodged between the stem and the leaf began to dissolve. The volume that dissolved was too much for the stem, and it rapidly disintegrated.

So, when applying pellets to your young cannas, please be careful. Keep them on the ground and ensure that none lodge on the joint between the stem and the leaves, otherwise, when the rains arrive they will dissolve the concentrated feriliser and overwhelm the leaf joint.

Crazy about Crozy

Madame Crozy
Madame Crozy

Monsieur Crozy’s goal was to turn Cannas from being primarily a foliage plant, with pretty but insignificant flowers, into a floriferous plant that could compete alongside any other genera in the flower beauty stakes. How well he succeeded can be judged by the fact that by the time of his death in 1903 the Canna was the most popular garden flower in both his native France and in the USA, where it even outsold roses.

Canna ‘Bonnetti’ has staminodes that are 45 mm. length and 13 mm. breadth, and by the time of his demise new cultivars were being introduced where the size had been increased to 66 by 35 mm, and this was achieved purely by selective breeding. The different colours and colour patterns in bloom and foliage were introduced by crossing his hybrids with other species, such as C. iridiflora. Basically, Crozy raided the species to supply him with any new feature he required.

The most famous of the cultivars introduced by Crozy was Canna ‘Madame Crozy’ (see the print), and this was later used by both Luther Burbank in California and Carl Sprenger in Italy to cross with the species C. flaccida to produce the first of the Italian Group Cannas.

Monsieur Crozy has been referred to as both Antoine and Antonin, the latter being a common nickname for persons called Antoine. He was also called Crozy aîné, which is the French for “elder”, however, it is reasonable to assume that he was not called by that nickname until late in life. Incidentally, there are canna cultivars called C. ‘Papa Crozy’, and C. ‘Antonin Crozy’, sometime refrred to as C. ‘Antoine Crozy’. The third of his christian names is the French version of Mary, which was a name commonly given to both genders in those days.

Antoine Crozy was succeeded by his son, Michel Crozy, who died only five years later at the tender age of 37 years, thus ending one of the most important and dynamic periods in the history off Canna.

Canna Crozy
Canna Crozy

It can be seen from this posting, how important the species are to us. The species collectively have provided everything currently found in our cultivars. There does seem to be an opportunity to introduce some new blood. Also, interesting seedlings can be obtained by using some of the early Foliage Group cultivars, produced nearly 150 years ago as the pollen parent, most are self-pollinating and would need to be emasculated if they were used as seed parents.

The Tiger Wins The Stripe Award

There were also a large number of very similar cultivars, many were obviously identical and just synonyms. But synonyms of what?

In 2005, at Claines Canna, we decided to grow as many of these plants as we could obtain alongside each other, to establish once and for all if they were different. We obtained specimens of:

  • Canna ‘African Yellow’ from Holland
  • Canna ‘Bengal Tiger’ from Philippines
  • Canna ‘Pallida Variegata’ from Holland
  • Canna ‘Panaché’ from France
  • Canna ‘Pretoria’ from UK
  • Canna ‘Pretoria Dwarf’ from USA
  • Canna ‘Striata’ from RHS, Wisley
  • Canna ‘Striped Wonder’ from USA
  • Canna ‘Tropicanna Gold’TM from UK
Bengal Tiger
Bengal Tiger

All of the participants in the trial were grown in identical conditions in 20 litre pots filled with Murphy’s peat based, general purpose compost. They were grown alongside each other but moved around regularly to allow direct comparisons with each other, and they were all on the same automatic watering system. None enjoyed any growing advantage over the others.

It was noted that all of the individual specimens had variations in colours, both foliage and blooms. Not normally noticed, but when closely examined they became obvious. The colours in the foliage varied, and the size of the stripes was also variable. The flower colours varied considerably, having a base of bright orange, and some with orange-red blush or even markings and many had a yellow rim or even a widish border.

What was also noted was that the variations were not only across different specimens, but on the same plant! The size of the staminodes was also variable, even on the same stem!

Although claims for C. ‘Tropicanna Gold’TM are for a large amount of golden yellow around the edges of the blooms, we never noticed enough yellow to justify the claim that it was different from the others, but C. ‘African Yellow’ was impressive on that score, and had a a yellow rim on all the flowers it produced. Canna ‘Pretoria Dwarf’ was the same height as all of the other trial participants, and that name seems to be misleading.

Our conclusion was that they were all the same plant, just many different names and a propensity to be variable, as are so many of the Italian Group, where the introduction of the wild species C. flaccida created a volatile mix. As this is reputed to be a mutation of C. ‘Wyoming’, it is not surprising that it is a little unstable. The other possibility was that it may be vulnerable to the quantity and quality of sunlight and water when the foliage and flowers were being formed.

Next, we examined Canna history to establish what was the correct name for this cultural wonder. Investigation revealed the cultivar originated as C. ‘Bengal Tiger’ at the Agri Horticultural Society of India, Bengal in the 1950s, probably as a result of the Radiation experiments that took place at that time.

Canna 'Bengal Tiger'
Canna ‘Bengal Tiger’

It was later transported to the African continent, by Sydney Percy-Lancaster, the Secretary of the Society, when he retired to Rhodesia, taking with him the Alipore Canna collection, originally founded by his father in 1890. Hence the synonym of C. ‘Pretoria’ when it was later discovered by US plant collectors in the late 1960’s growing in that continent; in spite of having already been imported directly to the USA from Bengal, India in 1963 by Glasshouse Works, again as C. ‘Bengal Tiger’.

Under the synonym of C. ‘Striata’ it was awarded the ‘Award of Garden Merit’ (AGM) in the 2002 Canna trials held at RHS Wisley, but that name belongs to an early Foliage Group cultivar dating from 1868, and still being grown under that name in Europe.

The list of synonyms (probably incomplete) that we have discovered for for this cultivar are:

  • Canna ‘African Yellow’ – confined to Europe
  • Canna ‘americanallis var. variegata’ – confined to USA
  • Canna ‘aureo-striata’
  • Canna ‘Damascus Road’ – confined to Southern USA
  • Canna ‘Imperialis’
  • Canna ‘Kapit’
  • Canna ‘malawiensis variegata’
  • Canna ‘Pallida Variegata’ – confined to Europe
  • Canna ‘Panach’
  • Canna ‘Panaché’ – confined to France.
  • Canna ‘Pretoria’
  • Canna ‘Pretoria Dwarf’
  • Canna ‘Striped Wonder’
  • Canna ‘Tropicanna Gold”?
  • Canna ‘Zebra Summer’
  • Canna ‘Zebra Sunset’

Summer Splits

Firstly, although we treat Cannas as perennials, in reality they do not need rest and in their native environment they grow for 52 weeks of the year, only slowing down if temperatures go too high. In temperate climates we know that they will be destroyed by freezing temperatures and so we store them in a safe environment over the winter and early spring, until the threat of frosts is past. The risk of too high temperatures is not a problem.

Cannas do not have a true state of dormancy, they simply have an ability to survive bad weather and growing conditions in the wild, things such as fires and drought. The large store of starch in the rhizomes means they have the energy to start over again. Anyway, after subjecting them to intense distress over the winter months, we then split them and start them into growth. In the process we always have a high number of casualties, not surprising when you think that they have been in a state of extreme stress for six months, then we aggravate that by splitting them and expect them all to grow a new root system as well as top growth for us to admire.

The garden trade knows that if they don’t sell the rhizomes in the spring, then they won’t sell many later. So, it makes sense that the trade cleans, splits and packages over the winter for a spring sale. The trade normally sells them in packs of three, so the customer has a high chance of getting something to grow, even if the rhizomes have been subject to bad storage and display conditions.

Beautiful Canna
Beautiful Canna

For gardeners with an established collection of rhizomes, it may be better to plant the established, semi-dormant clumps back in the ground and then, when they are flourishing again, with a proper root system, to split them. What make me start thinking about this? For the last few years I have been trading plants with another enthusiast in July/August, and I have been splitting the rhizomes for exchange the week before his arrival. Within weeks, my own plants have recovered and thrown lots of new, fresh growth and my gardening friend has lost none of his newly potted plants.

It is noticeable that the splitting has added new zest to the plants, but it is probably just the fresh food in the new potting compost or the bone meal that I add first before replanting in the ground, and the handful of fertiliser afterwards which creates that effect, and makes them appear to outperform their companions.

Anyway, I have determined to give it a try next year, and instead of working in the cold and damp of the winter in a poly tunnel, I will leave our collection alone and just replant them in May, and then do the splitting during the summer, when I can enjoy the exercise and weather. For those not convinced, why not try splitting just one of your plants this summer and try it for yourself?

Seed production

Seed Canna
Seed Canna

I have been asked to explain in as simple a way as possible, how Cannas produce seed. Let’s start by identifying the parts of the flower that are involved.

In the picture left, the central upright petal is the style, the female part of the flower. At the tip of the style is the stigma. The stigma is slightly sticky, and it is where the pollen must end up if it to fertilise the female ovaries, which are located below the style and out of the picture. The stickiness is caused by a sugar-type solution, which serves to both secure the pollen and also provide it with the energy to grow a pollen tube down to the ovaries.

To the left of the style is another petal called the stamen, and attached to the stamen is the anther, the sack where the pollen grows, becoming fertile at the same time as the flower opens.

The pollen in the picture has already been squeezed out of the anther, the pressures involved with the flower opening have the effect of squeezing the pollen onto the style. The cultivar in the picture is now waiting for a pollinator to arrive, it may be a bee, or a hummingbird, whichever, it is attracted to the flower by the prospect of drinking nectar, a sugary solution, produced in the base area where the petals all join together in a twirl, called the tube. But remember, there is not such a thing as a free meal! In return, the Canna expects to be pollinated.

The pollinator pushes its head down into the folds of the petals and drinks from the nectar, in the process it will attach the pollen you see in the picture to its body or bill, and then transfer it onto the stigma as it backs out again, a self-fertilisation. Alternatively, if it had visited another Canna prior to this one, it will have pollen attached to it from that one, and on its way down to the nectar that might be transferred onto the style, so performing a cross fertilisation.

In wild species, the anther is situated a little higher than the one in the picture and the pollen is automatically squeezed onto the stigma, that is what we mean when we say a species is self-pollinating.

Finally, at the bottom of the picture you can see the only real petal in the picture, although this article has referred to petals elsewhere, they are really staminodia, but more on that another time.

Canna ‘Burbank’ unveiled to the world

During a recent visit to Santa Rosa, California, I called upon Luther Burbank, and among other things was shown a new hybrid Canna which, when introduced, will probably create as great a sensation as Madame Crozy did. This plant is not a seedling of the well-known strains so deservedly popular, but is a hybrid between Madame Crozy, which has so long been the standard of excellence, and Canna flaccida.

Canna flaccida
Canna flaccida

Canna flaccida is a native of Florida, of a dwarf habit, and not a strong grower. Its exquisite light yellow flowers would, in spite of these defects, give it a high place in the garden were they not so very ephemeral. So frail and fleeting are they that an hour in the morning often measures their term of existence. I remember well that it was days before I got a sight of the flowers on a blooming plant of my own. The flower of C. flaccida is unique among Cannas in having something of the grace of an Iris and a peculiar silvery sheen that is very beautiful.

For years Mr. Burbank has been trying to make a cross in which some of these fine qualities of Canna flaccida might be united with the vigor and lasting qualities of the Crozy strain, but while many seedlings were grown and bloomed, all, with a pertinacity which is so often the despair of the hybridizer, followed one of the parents, and that Madame Crozy.

Last summer, in the third generation of hybridized seedlings, the new seedling appeared, and any one knowing Canna flaccida would have instantly recognized its parentage. Only a single seedling among thousands, yet Mr. Burbank feels that it well repays the trouble.

In the new and as yet nameless Canna are united, happily, the Iris-like form, the satiny sheen and the large size of flower of Canna flaccida, while the Crozy blood, giving to the plant a vigor of growth even surpassing either parent, and a lasting quality to the flowers about the same as Crozy possesses, is only apparent in the coloring in a lemon more intense than in flaccida, and a few reddish spots in the throat.

A marked feature of the new race is the development of some of the minor petals which in the Crozy strain are all but rudimentary. In the new Canna they are broad and flat, giving a bold fullness of outline until now quite unknown in Cannas.

Madame Crozy
Madame Crozy

Considering the predominance of Canna flaccida in this seedling, the most critical point is its keeping qualities. In this regard it is not quite the equal of Crozy. The flower opens up a clear lemon-yellow never before known in Cannas, and is unspotted, except for a few dots well in the throat. With age it becomes lighter in color, and in ordinary weather will last about as long as Madame Crozy, and I think for exhibition it is superior to any other Canna.

The foliage is of a light green, the growth a little stronger than that of Madame Crozy, the flowers well carried above the leaves and somewhat larger than those of the Crozy type.

The breadth of petal in the new strain is a marked feature which we can expect future hybridizers to still further develop.

Sign up for the newsletter to receive updates!