Hey everyone!

I had a question about a Meyer lemon tree, specifically a cocktail tree. (A Meyer lemon tree and key lime tree growing side by side.) I recently purchased it about one month ago from a local nursery. It’s a container pot and I live in Colorado. Our temperatures have started to rise so I put the plants outside. It’s been getting full sun, but the Meyers leaves are getting crispy, curling upward, turning yellow and falling off. Additionally, the fruit on there is starting to ripen.

This started to happen when I put it outside on our south facing patio. It’s in a black pot and I water it maybe once a week, but I do the finger test to see how the soil is. The soil is good draining, and the pot is a black medium sized pot. Originally I thought this was an overwatering issue (still could be) but the key lime tree definitely needed some water and perked up right away when I watered it. I also added some fertilizer to the pot so it could get some nutrients if that was the case.

Why would the leaves be turning yellow all around and falling off? Is this a reaction to getting more sunlight and being outside for hotter days? Should I get it a pot that’s not black and repot it? It gets really hot on my deck it faces the sun all day, but it has good shade too. Could it be a heating issue? How can I give one the water it needs while also not overwatering the other?

Thanks for the advice! Brendan