Lemon Tree Leaf Loss and Spots

[Minadora]

Hi folks! Hopefully you all can help me with my poor little tree so that it can survive the last month or so until spring time.

I inherited this little lemon tree back in July of 2016 when a friend of mine had to move across the country and couldn't take it with her. I've got a big veggie garden in the backyard so I kept it there until about October when our Canadian nights got a little too cold. Indoors, it stayed in my North facing bathroom by a big window for a little bit, but I felt like it needed more sun so now it's in my South facing bedroom where it's almost always sunny and warm. Probably around late November/early December-ish, it began to drop leaves. I messaged my friend who informed me that was pretty normal for it that time of year. I didn't worry much until about a month ago when it started developing some black spots on its leaves and continued to drop them pretty regularly. I don't water any of my indoor plants much during the winter because they dry so slowly even in my South facing room, but I make sure to check the dampness of the soil before watering it at all so it's not overwatered.

I'll post some pictures of the poor little thing and its leaves up close.

Could it be a pest? Or am I looking at a fungus/mold? Suggestions on my next steps? It has two lemons on it that are still ripening and we have maybe a month or so until I can move it outside again. I'm hoping it will make it to the spring time so help would be greatly appreciated!

Here's a bonus shot of it during summertime after I moved it into the shade 'cause it was getting just a LITTLE too much sun (hence the yellowing leaves). Just for comparison sake.

Thanks in advance for the help!

 

[Chuck]

IMO you have a fungus. Canada is not a great place to grow citrus and growing indoors can lead to problems. For instance heated air blowing on the plant will cause it. Lack of enough direct sunlight will cause yellowing. I don't think you plant is over watered but I do think that deep down in the root system it stays a little to moist. I would also check closely for hard scale on the stems of the plant. It is almost spring and I am sure the plant will survive until then but I would spray it with a copper based fungicide or 1 Tbs of hydrogen peroxide per quart of water. You can also use baking soda at the same rate. Citrus grows best in the heat of summer in hot places in direct sunlight. Do not move your plant into a less sunny area....especially in Canada. I would also take the plant out of the pot just to check the roots, to make sure it isn't overly root bound or too wet

 

[Minadora]

IMO you have a fungus. Canada is not a great place to grow citrus and growing indoors can lead to problems. For instance heated air blowing on the plant will cause it. Lack of enough direct sunlight will cause yellowing. I don't think you plant is over watered but I do think that deep down in the root system it stays a little to moist. I would also check closely for hard scale on the stems of the plant. It is almost spring and I am sure the plant will survive until then but I would spray it with a copper based fungicide or 1 Tbs of hydrogen peroxide per quart of water. You can also use baking soda at the same rate. Citrus grows best in the heat of summer in hot places in direct sunlight. Do not move your plant into a less sunny area....especially in Canada. I would also take the plant out of the pot just to check the roots, to make sure it isn't overly root bound or too wet

I took it out of the pot maybe a month ago to check on it and it wasn't root bound. It was pretty damp (the roots and the pot of soil) so I let the roots system dry a little bit while I changed the soil in the pot and replanted. Do you have a different suggestion?
I had read into keeping citrus indoors prior to getting it so I knew it was going to be tough, but I can't leave it outside when our nights reach almost minus 30 degrees Celsius. I think it would be way too damaged to recover the next spring if I did...
I'll try the spray and hope it helps! Should I be wiping down the leaves with the solution or just spraying them lightly without wiping them at all?

This little tree is so very different from the other plants in my personal garden so I just want to do what's best for it!
Thank you

 

[Chuck]

I took it out of the pot maybe a month ago to check on it and it wasn't root bound. It was pretty damp (the roots and the pot of soil) so I let the roots system dry a little bit while I changed the soil in the pot and replanted. Do you have a different suggestion?
I had read into keeping citrus indoors prior to getting it so I knew it was going to be tough, but I can't leave it outside when our nights reach almost minus 30 degrees Celsius. I think it would be way too damaged to recover the next spring if I did...
I'll try the spray and hope it helps! Should I be wiping down the leaves with the solution or just spraying them lightly without wiping them at all?

This little tree is so very different from the other plants in my personal garden so I just want to do what's best for it!
Thank you

You changed all of the soil a month ago? Was it the same as the removed soil?
Just add a squirt of dish soap to the mix, spray it and do not wipe. Just let it dry.

 

[Minadora]

You changed all of the soil a month ago? Was it the same as the removed soil?
Just add a squirt of dish soap to the mix, spray it and do not wipe. Just let it dry.

I did change all the soil. I wasn't given any soil from the previous owner so I had to pick some up. Did some careful research before changing the soil, following the instructions on this page for a 5-1-1 mix. http://forums.gardenweb.com/discussions/4089025/best-soil-for-an-indoor-potted-meyer-lemon-tree

 

[Chuck]

I did change all the soil. I wasn't given any soil from the previous owner so I had to pick some up. Did some careful research before changing the soil, following the instructions on this page for a 5-1-1 mix. http://forums.gardenweb.com/discussions/4089025/best-soil-for-an-indoor-potted-meyer-lemon-tree

What probably is happening is the tree is going through a mild transplant shock due to soil change. Transplant shock will weaken the tree somewhat thus allowing a fungus to take hold. Just spray it every few days and it will be fine.

 

[Fernsdaddy]

I would remove any fruit from the tree to help it recover from being transplanted.

 

[Minadora]

What probably is happening is the tree is going through a mild transplant shock due to soil change. Transplant shock will weaken the tree somewhat thus allowing a fungus to take hold. Just spray it every few days and it will be fine.

Thanks for the help!

 

[Minadora]

I would remove any fruit from the tree to help it recover from being transplanted.

I was trying to stay positive about the fate of the lemons but I do think the poor thing needs to focus on recovering instead of growing fruit. Thanks!