Avocados tend to get ragged looking when the weather is cold. They also don't like wet and cold roots. It makes them vulnerable to root rot. I wouldn't water them in the cold winter unless the soil completely drys out. I wouldn't fertilize them at all unless they are putting on a lot of new growth during the growing season. They are very sensitive to salt accumulation in the soil. My guess would be that it is suffering from the cold weather and/or salt accumulation from the information you gave.

Your tree is certainly being tortured by multiple causes. Avocados like high nitrogen food on a regular schedule. You actually have some fruit on your plant that does not have enough energy to grow leaves, remove the fruit. I would take the whole container and immerse it up to the rim in a tub of water, preferable water without a lot of Boron in it. Does your water source not make available a test report on the water they supply? After you remove the container from the soak and it drains the excess water, I would dissolve a table spoon of avocado labeled food such as that available from Lily Miller or if not available, Miracid or other citrus/avocado food per gallon of water. Good luck on your tree rescue. Al

Take 2 on posting my response...since the original didnt post the week or so ago.... I'd love to get the tree more light, but I live in a small apt, and only have a VERY small entry balcony that I share w/ 1 neighbor and this time of year especially only gets like 6-8 hrs of direct sunlight When I water, the water does drain, but has a tendency to sit for a few seconds on top before it all soaks in. The potting mix is something generic my garden designer friend used when we re-potted it in the spring. I feel that it's time to re-pot it again since I've noticed the main root trying to grow out of the hole at the bottom of the pot, but I dont have any deeper pots to put it in. I have one that's wider, but not deeper. Fertilizing? I'm just a poor student that's developed a sudden desire for growing things...this is a hobby going crazy and I dont really have money to get fertalizers. I hope to be starting a vermicompost bin soon so I might be able to get some worm tea in the future to use.

Hello, My avocado is 3 years old. Except summer time, it is always difficult time for it. Due to cold and windy weather, Avocado is always in-door during these seasons. There is not enough sun light in my place, so during day time I turn on bulb to provide additional light to it. Everything was relatively alright with avocado till recently. A few days ago, the bottom leaves started to turn brown at the middle + I can see yellow pattern on the leaves. The process is very quick (within several days). From time to time, I was able to see a small worm in the pot, but It seemed like not to be a problem at that time. But now, I not sure. I water it everyday around 150 ml (room temperature). From my opinion the pot is big enough. Any help is highly appreciated. Thank you in advance