Can you treat brown rot on the top of Agave Americana?
My 30 year old agave is on my patio. So far I had taken it into my garage during winter, this year I had to leave it outdoors as it is too wide to pass through any door. I wrapped it in fleece over the frosty winter period, but it has developed brown rot on the top, although it keeps growing new leaves and a lot of young plants, most of which I have removed.
Certified GKH Gardening Expert
Unfortunately, this is a sign that it has been left too wet for too long. These are desert plants, and need to remain pretty dry throughout the year.
You can try a handful DOLOMITIC lime and a tablespoon or so of WETTABLE sulfur.
It will be almost impossible to find dolomitic lime in your country, unlike here in the US. You can find hydrated lime, but this is decently toxic, and very caustic if used improperly.
You will have to find DOLOMITIC lime online. This is simply a mined formed of calcium carbonate and magnesium carbonate.
The sulfur must be wettable and contain a wetting agent to work properly.
It is possible that you may lose the larger Agave, but treating the smaller plants may be quite effective.
This article will give you more information on the care of these plants: https://www.gardeningknowhow.com/ornamental/cacti-succulents/agave/growing-agave-plants-in-pots.htm