A Gardeners Forum Forums Gardening Reference Gardening in 2004 Mysterious Lemon Balm Problem, HELP!

Currently I grow lemon balm in a pot and keep it
indoors in a semi-shaded area. It went through
a brief episode of downy mildew which I treated
successfully by spraying a mixture of baking soda
and water on the plant.

The plant has been thriving since then, growing
at a remarkable rate, but recently I have noticed
that the leaves are browning around the edges.
The browning creeps inwards along the leaf until
the leaf finally dies and drops off. As a
result, I have several stems that are essentially
exfoliated now. I am absolutely baffled about
what this problem could be since the plant was
doing so well before. I have not changed its
watering schedule or the plant food I give it,
and since it is indoors I am not sure what kinds
of mildews/fungi/bugs it may have been exposed
to.

I am a novice at this sort of thing so ANY
advice more experienced gardeners could give
would be greatly appreciated. I'm very fond of
my lemon balm and I would hate to see it die
without this problem being resolved.

Thank you very much
Belladonna

Perhaps the baking soda found its way into the soil and changed the pH. This may have put the plant into shock which is causing the leaf drop. Try repotting with fresh soil, if you haven't already. How is the rest of the plant; stems, roots, etc.? Any problems there? Is there any new growth?

Aha, that is a thought. The roots are fine
and the stems look healthy, although they do
tend to wither away when there are no leaves
on them (go figure hehehe). I think overall
the plant is healthy because it is constantly
sending out new shoots with lovely dark green
healthy leaves on them - it isn't until later
that these start turning brown.

I shall repot it as you suggest and report back.
Thanks so much for the advice, I never would have
thought of the pH aspect, silly me.

I'm glad you posted this - I got some lemon balm this year and just love it - I like to ruffle it with my hands for the scent.

I went looking around for lemon thyme (which I had great luck with one year), didn't find it, so I bought the balm.

I will come across some lemon thyme, I'm sure, but there's no rush - I can always do it indoors, I guess.

I divided the root of my lemon balm and successfully made two plants. I hope to have more. I keep them in pots on my picnic table.

If I see these problems arising, I will try the baking soda trick, then change the soil immediately afterwards.

(I've been spraying leaves with a light soapy water made with baby shampoo - it's keeping the bugs off - I just love it)


:-0

hello Belladonna, Lemon balm can tolerate a wide range of pH values, from 5.0(acidic)to 8.0(alkaline)...a value of 7 is considered neutral. so I'm thinking pH may not be your problem, but only a soil test would tell you for sure. The run off from your baking soda/water spray should not have been that much to saturate your soil, and later waterings would have leeched any excess away. Your lemon balm would have recovered in time on its on i'm guessing. Sometimes drafts from air conditioning or heating vents can dry/wither leaves if its blowing directly on the plant, especially the heating vents. Also low humidity indoors contributes to drying also. Hope this helps and good luck.

Just a thought, but do you have cats? You know they are always tempted to use potted plants as a litter box.......