Post G22-060, two gardening fails

Posted on September 26, 2022

 

Here are a couple of cases of “if it seems too good to be true, it probably is.”


Does a weak citric acid solution kill powdery mildew?

No.

See Post G22-039 for background.  This is based on a product offered on Amazon that said it would kill powdery mildew on plants.  That product was merely a very dilute solution of citric acid in water.  I was originally going to do a formal test, with a “control” patch, but the powdery mildew didn’t show up on time.

Instead, here it is firmly established on what’s left of my summer squash.  Near as I can tell, a dilute citric acid solution had no impact on well-established powdery mildew.  Here are two pictures, one before spraying citric acid, and one about a week after.  Any apparent difference is just an artifact of the lighting, compounded by the complete loss of some of the leaves.


Do bamboo leaves make a good weed killer?

No.  Or, at least, not good enough.  Or maybe it’s just very slow at it.  All of which is a pity, as bamboo surely kills lots of useful plants.

See Post G22-052 for background.  Bamboo is one of many allelopathic plants, that is, plants that produce poisons to keep competing plants in check.  I figured, why not give it a shot as weed killer.

Before:

Roughly seven weeks later, I pulled back half of the now-brown bamboo.  Unfortunately, there’s still plenty of live weeds growing through the driveway, like so: