Melvin Wei's video: Growing Avocado Trees from Seeds Days 86-133

My avocado seedling really took off after I moved and a heat wave struck, despite the lack of direct sunlight on my new balcony. I suppose the ambient temperature is the most important factor for both seed germination and growth. If it's too cold or hot, it's game over. The second most important factor in plant health is whether the root system is getting enough oxygen. Third is water abundance, and fourth is nutrition. Of course a plant must receive some light, but even in the absence of direct sunlight, plants can still get off to a great start. I have seen pictures of avocado seedlings growing in tap water or tiny pots of soil indoors for a year or years with success. In the case of avocado seedlings growing in containers full of tap water, the external nutrition is nonexistent, the roots get dissolved oxygen from the water (it cannot have any organic matter decomposing in it), there's unlimited water, and there is very little light indoors, but the even, favorable temperatures throughout the days and nights help tremendously, especially in colder temperature climates.