Lily of the Valley – brown spots on leaves

(Question)

Hello!

I live around the East York area and have recently bought a Lily of the Valley from a nursery which I am trying to keep as an indoor houseplant. It is currently beside my orchids and my peace lily, and is located in my living room where it receives bright, indirect light. Additionally, it is currently in basic potting soil (humus, peat moss, sand, and perlite). I only water this plant when the top soil gets dry, and it’s in a plastic pot with several drainage holes at the bottom.

I have noticed after about 2 weeks since I’ve brought my plant home that brown spots have started to appear on some of its leaves. I’m wondering what may be the cause of this. I have looked up online for possible causes and most sites say it’s from the humidity which results in bacterial or fungal infection. If that is the case, is there any way I can save my plant and if so, how?

Thank you so much for your help!

(Answer)

Thank you for contacting Toronto Master Gardeners!

Lily of the Valley (Convallaria majalis) is generally easy to grow in a variety of soil conditions. It can be susceptible to aphids and spider mites. Stem rot, leaf spot, leaf blotch and anthracnose may appear but usually are not significant deterrents to growing this plant. Foliage decline will occur in hot summers, so perhaps your plant was already becoming stressed from summer heat when you purchased it, or it is too warm in its indoor location.

As you know, Lily of the Valley can be a beautiful and fragrant indoor plant.  The following link from Gardenista provides some additional information about growing it indoors on a windowsill. https://www.gardenista.com/posts/forcing-lily-of-the-valley-indoors-windowsill-garden/

(Please note that all parts of this plant are very poisonous because they contain cardiac glycosides.)