Have a 3 year old Meyer lemon tree in a pot which is indoors for the winter. Noticed several budding flowers- should I fertilize now and please recommend what fertilizer to use.
When to Fertilize?
Certified GKH Gardening Expert
You should only fertilize in spring unless you use a liquid feed. I recommend a granular once per year. There are many on the market made, specifically, for citrus.
It is also worthy to note that they will not be able to produce fruit indoors without supplemental lighting. Even a south facing window will not do, as the light is still filtered a little through the glass.
I recommend at least 200 watts of horticultural grade lighting. I prefer LED as they consume less energy, and produce less heat.
Here is an article that will give you even more information: https://www.gardeningknowhow.com/edible/fruits/citrus/growing-citrus-trees-indoors.htm