I also have this problem. I planted them 6 months ago, they flourished outside (even got flowers), then were moved inside as the temp. became cooler. I have them now under artificial light (where I first started them 6 months ago), and they are growing but the leaves turn black and fall off after reaching an inch or two in size. I suspect some watering issues, change in light, as well as temp. Aka stress. Just not sure if they are going to make it. Also, I they do need nutrients from time to time, which I have not done. I don't have any answers - just throwing out the things I am considering and still looking for more definitive answers.

Your container looks too small for a tree, even a baby tree. The roots look girdled. It means they have been circling the base of the tree just below the surface, because they can't spread in this small container. Girdling roots are petty much a death sentence for a tree because they choke off the flow of water to the top of the tree. But I've heard that some folks have been successful in fixing this condition by cutting the roots. I'll let others weigh in on that. In the long run, however, you will have to plant this tree outside. It's a fun project, but avocados are not houseplants. It may stay alive but will not thrive.

I live in Buffalo, NY there's been a few colder days with one or two being below freezing. My apple tree had a few similar spots, so I'll remove those just in case.

The question now is top watering and bottom watering. Do you have strong feelings on this? I'm pretty set in the idea that top watering is best, even if only for the fact that flushing the soil while watering from the bottom would be more difficult (read as practically impossible) than I would want to mess with. Also, if you're watering from the bottom, the fact that bonsai media don't have a lot of wicking action (should have practically none) means all moisture and fertilizer salts would be at the very bottom of the pot. The only time I would use bottom watering is if the planting was a plant with pubescent (finely haired) foliage that reacts poorly to getting wet, as in African violets, or if the soil was capable of wicking water high enough to moisten at least most if not all of the soil column. Since the only media that will do that are very likely to be much too water retentive for best results, I wouldn't consider using those types of media unless it was an 'only choice' situation. Can you suggest a shop where I would find a watering can appropriate for that? I really like this Dramm 2L watering can. It comes with a rose for sprinkling, but I never use it. The white tool is a disposable nozzle for tubes of caulking/ caulking guns. It slows the flow of water and allows you to cover the entire soil surface. Water moves primarily downward only in bonsai media, so the grower must take care to wet the entire surface. I have so many trees and they're so close together it's sometimes like trying to thread a needle to get all the soil surface covered. The rose catches on branches and guy wires, so I go with the homemade gadget. I make them straight or curved. My little 2L watering cans are more than 30 years old and still going strong. Should I be watering the leaves as well as the roots? No. Try to avoid wetting foliage, unless it's a REALLY hot day, especially when/if you water in the evening. One part of the disease quadrangle is time. Fungal spores need a long enough incubation period, during which they are continually moist, in order to vex us. To deny the incubation period is one way to deny the disease. Some people are saying to water daily and some weekly but I can't understand how it could be daily? I do understand finding a pattern that the plant seems to like but daily watering seems like a lot. No one can give you meaningful advice about how often to water unless they are very familiar with the medium you're using, the weather you're experiencing, and in cases other than bonsai, your watering habits (do you water in sips? do you flush the soil when you water, is your medium water-retentive? ...... those kind of questions. Bonsai are more like pets than plants in some ways. They require at least a check on their water status daily, if not watering daily. I don't water every plant every day, but I drag the hose all around the benches and water at least 3/4 of my bonsai plants daily in the summer. In winter I water indoors on a split schedule (the media I use allows watering on a schedule as opposed to on an 'as needed' basis) with plants in the larger pots getting water at 6 day intervals and the tiny pots get water every 3 days. You'll need to find your own rhythm. We really do have a lot of nice light coming in through our windows year round here and I think bonsai would do well with it. I imagine people outgrow their window space as their hobby expands and move outdoors. Bonsai trees want to be outdoors and will show their appreciation if you afford them that accommodation. Insulated windows omit at least 309% of visible light and walls all of it, so even in FL you'll see a difference between indoors and outdoors. As for the potting soil from Peter Tea, do I use only that and no added dirt? I use 2 basic media. This one for misc stuff other than woody plants and succulents: The one below is what I use for woody plants which includes bonsai in bonsai pots and potential bonsai growing on in nursery cans or larger bonsai training pots: I make both of these media myself and amend them if required with other ingredients I keep on hand. Am glad you saw the video and enjoyed it enough to watch. I just assumed people bought their bonsais or traded with friends or fellow club members. I purchased a lot of woody material in the first 10 years of my practicing bonsai, some of it was rough=shaped to at least the degree a trunkline was discernible, the tree within the tree, so to say. After that period, I started almost all trees from cuttings and grew them out in raised beds. The tree in the middle had just been chopped back (spring) and lifted from a raised bed. It was 5 years old and roughly 8 feet tall. The branch sticking up will be the new leader or the top of the tree. The tree is chopped back so it tapers quickly from a fat trunk to a thin top. Same tree later that summer. Moss helps the wound where it was chopped to heal. ^^ 2 years to go. Note how the branch I mentioned is thickening and becoming the new top. The tree will be chopped 2 more times before serious work begins on the branches See where it was chopped 2 more times? Wound is healed, and the others soon will be. This image was taken summer '19, so the tree has had 2 more years of development. It's much filler and thicker, not much taller, and I've been working on reducing the leaf size so leaves are about 1/3 or 1/4th the size of the leaves above. Al, I wanted to ask about bonsai pots. Why are some so incredibly expensive? I understand if they're made by hand but does it have anything to do with the growth of the plant or is about beauty or status? (I realize they're all made by hand, but most are done very quickly without high quality control standards.) Do some have more precise drainage that increases their price and value? The high quality, hand-made pots will all have excellent drainage. Some of the stamped and molded pots will have areas in the pot lower than the drain hole, so water pools there - not a good thing even if it's only 1/8" deep. High quality pots will hold no water in the pot material, making them impervious to frost. Hand made pots are glazed and toned by hand and often fired in wood-burning kiln which imparts a somewhat unpredictable but unique appearance. A good trees deserve good pots that compliment the tree but never serve as the focal point of the composition unless the pot is purposely being scrutinized. Here's the commentary and discussion I found on perched water. https://www.bonsainut.com/threads/perched-water-tables-myth.1588/page-3 Reading it got me thinking! For instance, on the Fukien Tea bonsai I bought, the soil appears to be all small rock and on top of it the tree roots appear to be in a ball of soil. I couldn't understand this. Now I'm wondering if it's about drainage. The folks taking part in that discussion were drawing no distinction between ballast and a drainage layer. Ballast reduces the volume of excess water a medium can hold by displacing media that holds water. The image on the right shows how a brick, serving as ballast, reduces the amount of excess water a planting can hold. The image in the middle shows how water perches above the drainage layer. They were describing a thin layer of coarse material at the pot bottom when it was actually ballast. In order for it to be a drainage layer, there must be clear delineation between the 2 substrates comprised of different size material, and, the size of the particles in the lower layer must be at least 2.1X >the size of the particles in the upper layer, and, the size of the particles in the upper layer must be smaller than approx .100" or water will not perch in the medium. You can't toss a couple of handfuls of coarse pebbles in the pot so the layer is only 1-2 pebbles deep, then mix in the substrate and rightly call that a drainage layer when it's ballast. After reading all four pages of the above 'discussion' (mostly childish bickering) I found what may be a comment that's correct but I wanted to ask you. Are some growing their trees using rock only to prevent perched soil and nutrients added by fertilizer to give the tree it's food? Sort of. Conventional container gardening is much closer to hydroponics than growing in the earth. We wet the medium, the water should quickly flow out of the pot, leaving fertilizer and moisture inside of soil particles which are porous, on the surface of all soil particles, and at the interface where particles contact each other. The spaces between soil particles should be free of water (except vapor) and full of air. You can only accomplish that with a soil made of particles larger than .100" and at least fairly uniform in size. I can't understand why the two stores in Orlando sold bags of almost pure dirt? The same reason they make a fertilizer for nearly every type of plant under the sun - peoplewill buy it. If adding dirt to real bonsai soil do I just put it on top. I know that can't be right either. I'm missing something and that 4 page conversation confused me more. I do understand that the smaller the pot the greater the chance of perched water. Not quite. IF you are using a medium that supports perched water, the SHALLOWER the pot is, the more serious the effects of a PWT will be (because a larger fraction of the medium is saturated in shallow vs deeper pots) and the more difficulty you would have dealing with it if you don't know how to trick water into exiting the pot. Thank you for showing the diagram. I want to make sure i get that right before I do anything further. Most welcome. Al