I had a very nice afternoon seeing a friend I haven’t seen in a very long time due to, we all know, COVID! But yesterday, we finally met and she gave me a tour of her houseplants, asking various questions. Some of her plants in her home are traditional houseplants, some are succulents, and a few plants are in her basement for the overwintering phases of plants in our area of Connecticut.

Canna Lily Plant in the Basement

She actually wanted to show me how her Canna Lily plant in the basement, still in its pot, was pushing out new growth and also had a bloom starting on the tip of one stalk, no less, but the leaves of the plant were covered in brown spots. My initial question to her on that issue, was did she have any water dripping down on the plant’s leaves by chance? She said, no, no issues with that, however, her basement is probably on the moist side and the leaves were suffering. My immediate suggestion was to cut all the foliage off, especially since the base of the plant was showing a new shoot coming up from the rhizome below the soil, so she will get new growth on it as soon as we can place our pots back outside this year, around Memorial Day. Plus damaged or foliage with issues will only drain the plant’s energy, so it is always a good idea to cut off anything unsightly or bad on a plant if possible, always using clean, sterilized tools so you do not transmit any issues later when using those tools again.

Black Or Brown Spots with a Yellow Halo

I was curious, however, about the spots. When you see this photo, they are somewhat in a pattern. That led me to suspect it was more than just a bit of winter stress. There is something going on here. I thought, I will look it up in one of my many gardening or plant reference books when I’m back home.

I have many books on my shelves in my home office. Over the years, I’ve collected many but I have never really written about any of them here on this blog. Perhaps today is the day to start. One place which I’ve stopped in to get various books in the past is a small bookstore in Northampton, Massachusettes. I was just there about a week ago and popped in. They don’t have an extensive collection of plant related books, but I tend to always fine a “good one” in a little corner of the store, where a limited supply of plant related books are stocked. I think whomever picks them out has a good eye.

I prefer to review the books in person versus buying online because I kind of know right away if the book is a good fit for me. I’ve learned a great deal about plants over the years, and I’ve read lots of books to find answers, learn more, and for the pure enjoyment of reading about gardens and plants. Some books cover things I already know or are already in another book on my shelves, or maybe it is too complicated, but whatever the reason, I usually instinctively know if I will like it. And I did like this one.

How Not To Kill Your Houseplant Book

A book I picked up at that cute little bookstore a year or so ago during a prior visit is called, “How Not To Kill Your Houseplant” by Veronica Peerless. It is a small book, easily held in your hands, with a yellow hard cover. I remember I flipped through the pages and thought, hmm, this one is cute and decent. It has clear photos of the plant and goes over how not to kill it, best locations, light, watering and feeding recommendations, and care, etc. It has some information on common bugs and problems but it is not overly extensive or technical but just enough information to quickly find what you are looking for. It is also a visual type book, where photos lead you to what you may need to research.

So this morning, I pulled this little book out and immediately spotted the leaf spot in the book’s Plant Diseases section. Granted, Canna Lily plants are not technically houseplants. Out here, in our area of CT, I view them more as great tropical plants we put out in the summer months in container gardens or gardens. They are not winter hardy here. They grow tall, bloom summer into early fall, are easily stored by moving the pots into your basement as is, or by digging out the rhizomes from under the soil and storing those in boxes during our winter months. And I should note that some Canna Lily plants do suffer from various virus type of diseases, and some are not curable. In “some” cases, you may have to toss the whole plant.

Whole Pot of Canna Lily in the Basement

My friend, Linda, has the whole pot in the basement. The plant is pushing out new growth from the top of the soil, sensing the arrival of spring, and there is a window nearby too, so it did get a bit of light during the winter months. But, as I read the description of the Leaf Spot in the little book I picked up in Northampton, it said the problem is often caused by bacteria or fungi, which are more likely in damp conditions. Most basements are damp, so that made sense to me. Also, the fact each of the brown spots on her Canna Lily leaves had a “yellow halo” as described in the book leads me to believe it could be a Leaf Spot issue (or it could be a virus of the canna plant).

How to Treat Black Spot

My recommendation to Linda was to just cut it all down, stems and all, and it will regrow fresh growth when we move our plants outdoors in late May. Also, I suggested to her that if we get a spring tease day soon, put the pot outdoors for fresh air to allow the soil to dry out. But this may not solve the issue and she may need to treat it with a fungicide, which the book (or author, I should say) of the book recommends.

The book doesn’t specify any type of fungicide or particular brand. That is something you may want to ask your nursery person about when you go shopping this season, or when you order it online, be sure to read what the spray treats before clicking “add to cart.” However, Canna Lilies plants are easily dug out. Perhaps another route is to take the root ball out and pot it fresh in the summer. Without researching it further, I can’t say if a spray will fix it completely. It could be an incurable virus, and well, more research from my other plant books is required to make a more thorough assessment.

Other Plant Problems are Featured

Again, one of the reasons I enjoyed this little handy book, I think is partially their photos and images are well done. It shows other houseplant diseases such as, gray mold (Botrytis), Crown and Stem Rot, Powdery Mildew, Oedema, Sooty Mold, and Root Rot. Ack, those all sound horrible, don’t they? And of course, it shows the Leaf Spot issue discussed above. But a photo or diagram of each is depicted in this book.

Nice Visual Aid

This book is a nice simple visual aid. In the front, rather than your typical table of contents, are photos of each plant featured in the book with the page number and plant name. So, if you are unfamiliar with technical or botanical names of plants, you may easily recognize your houseplant from the photo, and then flip to that page.

Sometimes, I never get to read a plant book in it entirety. However, I super enjoy those days when I can sit in my greenhouse with a plant or gardening related book from my stock and flip through to read it or review sections of it. I recommended this book to my friend because I saw many of the houseplants she has in her home in this little book and thought this will be a handy reference for her.

BTW, I get no monetary payback from anything I post on this blog, so the book review is just my humble opinion. My payback is being able to help a friend with their plant questions. Feel free to ask me anytime and if I don’t know the answer, I will try to look it up for you.

Thank you for visiting today.

Cathy Testa
Container Crazy CT
Broad Brook, CT