Sterilising soil
hi all
I think my delphinium has crown rot I've read that I need to remove the plant and sterilise the soil but I can't find out how to sterilise my soil, the delphinium is in a flower bed surrounded by other plants
can anyone advise if and how I should treat the soil
thanks in advance x
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Are you in the US? Nearly all references to crown rot are US based or talk about 'warm, humid conditions' not exactly prevalent here in the UK.
Here the most likely explanation for failure of shoots is likely to be slugs and snails, though if your delphinium is in a very wet place, it may just be 'normal' winter rot and the remedy would be to improve the soil and drainage. If that is not the case then I would probably add protection against the molluscs and leave it to see if it can manage a few new shoots
Anything that would sterilise the soil would render it unusable by other plants for some time, unless you chose to remove it all and microwave it!
If the choice is sterilise the soil, or grow different plants, I'd grow different plants.
I'm no expert...but if you sterilized soil, wouldn't you be killing all the microorganisms in it? Wouldn't that mean the soil was "dead"? I thought that healthy soil was crawling with beneficial stuff...... lovely earthworms etc.
I presume this sort of rot is caused by a bacterium in the soil, and it's probably one of those things that are widespread, but only cause a problem when the plant is suffering with poor drainage or some other kind of problem. Kind of like most houses contain a few dry rot spores, but only get an outbreak when a hidden pipe bursts somewhere.
I would lift the delphs with a good clump of soil, dispose of the soil, and pot them on into clean gritty compost and quarantine them. They may come back from the dead. I would replace clean soil into the hole and plant something else that's really well suited to the garden conditions, and tough, into the spot where the delphiniums were. Maybe experiment with Monkshood, as a late season delphinium alternative? If you want to plant replacement delphiniums, ensure a well drained spot with decent air circulation. My mum has some growing in a dry corner on rubbly soil, thriving on neglect.