Hi all,

I've had this potted lime tree for about 6 years (the last four in the Pacific Northwest), it has recently experienced a pretty severe episode of leaf drop (about 1/3 of its leaves and fruit drop), and would appreciate the community's thoughts on overwatering, underwatering, nutrient issue or something else. Some of the leaves that drop are yellowed, some are still green (but don't look great).

Here are some details and pictures below if you want to skip to the point (I didn't do a great job training it during its youth, as I figured any growth was good growth, and I've been using strings to help direct it upwards):

It lives indoors in a western facing room in the late fall, winter and early spring (with opportunistic outside time outside when the weather cooperates), and then lives outside once nightly temperatures get above about 55 degrees. The outside space is also westerly facing and gets great sun from early morning through sunset.

It has recently experienced a pretty severe episode of leaf drop (about 1/3 of its leaves and fruit drop), and would appreciate the community's thoughts on overwatering, underwatering or something else. Some of the leaves that drop are yellowed, some are still green (but don't look great).

I typically water in the morning and give it about 1/3 of a gallon of water daily or every other day (whether inside or outside, winter or summer, this has been pretty successful for the last several years).

I've used a miracle grow (or similar brand) of potted soil for the last six years (the one that comes in the blue bag and home improvement stores). I replace the soil every six months or so (as the directions on the bag suggest). We are about 4 months into the current bag. Drainage has been great. Over the last year I started using a fertilzer specifically marketed for use with citrus plants. I've added fertilizer every 3-4 months.

As detailed below, there are several potentially confounding variables, so would appreciate folks' thoughts!

There are several variables.

1) I moved and began leaving the lime tree outside overnight during an early warm spell, but over the last several months the weather has bounced between cooler temps at night (high 40s to low 50s) and with highs in the low to mid sixties (I would normally move the tree inside during this weather, but recently had knee surgery. More recently the temperature has been high 50s to low 60s at and 75+ during the day.

2) due to the knee surgery and the fact that the soil has been damp in the mornings, my watering schedule has been thrown off. Sometimes I water every day, sometimes every third-ish day.

3) a pretty bad outbreak of scales. Several branches were completely covered with them, several leaves were completely covered down the center vein, and many of the leaves were covered in the mold from scales' secretions. Last year the hornets/wasps took care of the problem by eating all the scales, but this year they seem more interested in the honeydew itself. I've manually removed about 80% of the scales and wiped most of the "soot" off the leaves.

I see a couple of options, some conflict with each other/based on what the cause is. Water more. Water less. Move back inside at night. Move back inside full time. Fertilize more. Fertilize less. Try neem oil/or fungicide to address scales and/or any other issues. Introduce praying mantis/ladybugs to eat the scales.