Mr Yorke stated that, "I had been having some aphids under the surface in a few spots, particularly where the soil was more open, so it was recommended I spray with Rogor 100 (not rogor 40, this systemic one is stronger) and at the last minute I laced the mixture with some Seasol. In 3 weeks I had noticed a considerable difference, in fact old plants had enormous growth from the base, they had whole batches of new shoots and leaves. Needless to say, I did the same spray 3 weeks later".
The attached shows the result, obviously the leaf on the left is one of the old leaves, the two on the right are much stronger.
On reading the label on Seasol, I see that it promotes good growth and helps the plant fight against viruses. Note it doesn't 'cure'. Anyway, I have old plants with a whole new lease on life and I am watching them most closely in future. The Curator of our gardens here tells me that Seasol is a wonder fertilizer, good to get rid of caterpillars and the like as well.
Just thought this may be of interest. I find Seasol also beneficial in soaking bulbs before planting out."
My own take on this is very simple, possibly pseudo-science.
This is a sea-weed based, organic fertilizer. (The name is a conjuncture of "Sea" and "Sol", the French word for sun). There are, I hope that I remember my biology right, 72 bio-minerals, i.e. plant nutrients. Most have been leeched out of the soil over the millions of years that the earth has been exposed. However, they are still in suspension in the sea, and sea weed contains traces of all of these nutrients. The application of a seaweed based fertilizer is one way to ensure that our Cannas get everything that they would otherwise lack.
Fertilizers typically provide, in varying proportions, the three major plant nutrients (nitrogen, phosphorus, and potassium), the secondary plant nutrients (calcium, sulfur, magnesium), and sometimes trace elements (or micro nutrients) with a role in plant nutrition: boron, chlorine, manganese, iron, zinc, copper, and molybdenum. It is those last seven micro nutrients that are present in sea-weed, but not in most cheaper commercial fertilizers.
Now, if virus is still present can only be determined in a laboratory, but if all my foliage looked like the ones on the right of Bernard's photograph, then I would never complain.
I have identified that "Mr Fothergill" is the UK representative for "Seasol", and I have already identified my local UK supplier. Now we have to try it out and see what happens.
Cannas by Bernard Yorke