Every so often a gardener will send me a gardening solution that is a real gem.
This happened recently via an email from Sue about her and her families experience with potassium permanganate, or as it is more commonly called, Condys Crystals. ( KMnO4 )
(Most uses of potassium permanganate are for its oxidizing properties.)
It is a strong oxidant that does not generate toxic by-products therefore KMnO4 has many special uses.
A solution of potassium permanganate can assist in the control of a number of diseases on plants.
Here is the email I was sent:
I came across an old post of yours (2008) today and thought on the off chance that if you are still interested, I’d pass on some info. My father was a very accomplished gardener in South Africa.
He had the most beautiful garden and had a really soft spot for roses, often rescuing them from the rubbish tip as gnarled dead looking bits of wood; he’d coax them back to full glory and crow about how stupid their previous owners were to toss them out.
One of his standard soil treatments was Condy’s crystals or potassium permanganate.
He would mix up a mild (pale lilac) solution and drench the soil around each rose in the spring before the leaf buds appeared and then spray the leaves once they had hardened (beyond the soft red stage) a couple of months apart.
Any sign of black spot or rust was immediately treated with the same spray but these were rare.
He also treated white powdery mildew (or any other fungus) with Condy’s wherever it appeared, as both a soil drench and spray on the plants.
My parents grew all their own veg and my mother always washed anything coming in from the garden that was to be eaten raw, in a weak solution (barely lilac). I’m not sure about the necessity of the latter but none of us appear to have suffered any negative effects.
I moved to the UK some years ago and found that black spot and rust on roses and various fungus infections on veg were much more of an issue here in the damp than in SA. I looked in vain for Condy’s and finally last year bought some on a trip back to SA.
We are having the wettest summer on record so battling fungus has been pretty constant this year but although my roses do have some spots they are far healthier than they have been in past years (could also be all the water of course). I didn’t do the soil drench in the spring but intend to do one last thing in the autumn and again in the spring for next year.
Kind regards, Sue Breetzke (UK)
I have suggested in the past for gardeners to use potassium permanganate as sprays for rust on any garden plants and have felt that it would be good also for a number of other plant diseases.
Drenching the soil as Sue’s father does with a solution of potassium permanganate would help wipe out disease spores that are lurking in the soil, under plants waiting for rain or the right conditions to migrate to the foliage and do the damage they cause.
Potassium permanganate used at ¾ a teaspoon into one litre of water with three desert spoons of table salt, dissolved then added to nine litres of water makes a good soil drench for helping to control club root in brassicas. (Drench each planting hole with one litre of the mix prior to planting the seedling.)
This same formula could be used to advantage in areas where you wish to sterilize the soil without harsh chemicals.
Used at this time of the year, under roses and fruit trees, would assist in reducing the disease problems that will likely occur as the season progresses.
This could be very beneficial in stone fruit trees that suffer from curly leaf and bladder plum diseases.
A milder solution of about ¼ a teaspoon per litre of water could be sprayed over the branches and later the foliage when it has emerged for disease control.
An application soon after rain would be advisable as that is a danger time when spores rise up to affect the foliage.
Potassium permanganate is inexpensive as many garden centres stock 150 gram jars for about $12.00 and 150 grams will go a long way.
Gardeners love to have very healthy roses with lots of flowers and this can be achieved if you change the way you garden (if you haven’t changed already and are enjoying lovely gardens)
Firstly do not use rose fertiliser or nitrophoska for their food, both products damage the soil life and can be likened to cheap fast foods.
Instead use only natural products such as sheep manure pellets, blood & bone, dolomite, any animal manures, compost, Bio Boost and Fruit and Flower Power. These foods will feed the soil life, build their populations and help to make for healthier roses. Also apply some Rok Solid to the soil under the roses and give the soil a watering with Magic Botanic Liquid (MBL). These will add minerals and elements to the soil not available in either chemical fertilisers or natural products.
Sprinkling Neem Tree Granules on the soil at this time may help reduce insect pests. To ensure that the soil life is not harmed by the chlorine in tap water put a 10 micron carbon bonded filter into your hose line. Alternatively store in a open vessel, tap water, to remove the harmful chlorine.
Chemical sprays that were commonly used for roses appear to do more harm than good as pests and diseases have evolved to be resistant against the chemicals. They are now very expensive, damaging to the environment as well as your health and not the answer to having healthy roses as many gardeners have reported.
Instead use maybe the potassium permanganate as the email suggests for fungus diseases.
Alternative would be sprays of Liquid Sulphur and Liquid Copper (in the blue bottle)
The Liquid Copper 250 ml bottle makes 250 litres of full strength copper spray making it great value for money.
For Insects; Neem Tree Oil will assist in control without harming beneficial insects and will deter possums from eating your roses when applied 2 weekly.
You can make a good difference to your roses with a two weekly spray of MBL and the Neem Tree Oil can be added to this if required.
The key to healthy roses is go natural and put the expensive chemicals in a safe disposal facility.
Editors note: please take precautions when handling any chemicals. Store in appropriate places away from children and read all label precautions. For more information about Condy’s Crystals please follow the link below.