Hello, I have few questions about these plants.

1. Annona Cherimola, I growing this tree from a seed in North Europe. But in late autumn it dropped half of it leafs. Is it normal?

2. Persea Americana, this plant also dropped half of it leafs, I think there is some kind of problem. Can I expect if I would recover this plant, it will grow up new leafs in the place where old were?

Hi David and welcome. Here''s the database entry for your Annona. It says it is evergreen but "may be briefly deciduous". So the question might be, is it cooler at night where you are keeping this plant? Also, how much light is it getting. You are fairly far north, and a tropical fruiting tree needs a lot of sun and warmth to keep growing "normally".
Custard Apple (Annona cherimola)

Pretty much the same questions apply to your avocado plant. They do lose leaves regularly through the year so that would be more or less normal. But I would say keeping it as warm as you can, and giving it as much bright light (preferably direct sun) as possible will keep it happy.

Also it's fairly important to note that tropicals raised as houseplants in northern climes will certainly slow down their growth rate during winter anyway. So you need to fertilize and water more sparingly than you do in warm weather when you can grow your plants outside. Too much fertilizer or water (or both) when the plant is growing slowly can cause leaf tip burn and other damage.

Thank you for your answer,

The plants are placed on the windowsill, they are for ±7 hours in daylight, and for 5 hours in "grow light". The temperature are 21-22 degrees by C. I watering them once a week. There are also Guava, Banana and Coffee tree, which look pretty ok . But avocado lost 15 leafs of 33. Also as I see the other 5-6 leafs are damaged. You can see attached pictures. Btw, I noticed, that in places where dropped leafs were, annona grow a small buds. Maybe this are a new leafs which will spread out in spring?

Glad to hear you have some grow lights for your tropical plants. They are very likely all responding to the lower light levels from outside and cooler temperatures. Does your window get direct sunlight for part of the day? if not, it might be a good idea to increase the time on your grow lights through the winter months.

On the avocado, I'd suggest you lay it on its side and slip the pot off to check how the roots look. Avocadoes send deep roots down sometimes, as they get taller they need it to stand up if they are planted in the ground. The tree is naturally a tall, slender shape as it matures. So if you find roots going round at the bottom of the pot, you need to put it into a much deeper pot as soon as possible. The new growth where the old leaves fell off is a good sign.

Unfortunately there are no sunny days in this period, every day is cloudy. Anyway my window get direct sunlight only in last winter month. I will set up grow lights for a 10h per day.

Avocado roots looks good, they are not spread out from the bottom and does not going round.
I remember a spring when my avocado dropped few leafs, unfortunately still there are no new leafs.
Other leafs looks like this:

http://oi44.tinypic.com/6jd7yq...

Your indoor temperatures may be cool enough to keep the tree from growing for a while, but the leaves in your pictures look fine. I wouldn't worry.

Here, where the trees grow outdoors in people's garden the temperatures range from 8deg.C at night to 24 C daytimes, with some days cooler, and some nights going a little lower as well. The trees will lose more leaves if we have a series of cool nights, and do not show new growth until it warms up.

It's possible that your grow lights will warm the area around the plant a little more, and give you new growth sooner when you increase the time the lights are on. But if not, just wait until spring. Modify your watering according to whether you are seeing growth, too. If no growth, water sparingly.

I am not sure I shouldn't worry, I attached photos of avocado and annona.
As you can see annona leafs from the top looks ok, but from the bottom there are some brown spots.
Same on avocado leafs, almost every leaf now looks like that one in photo.

Well, thank you, Elaine

I guess what I'm saying is you shouldn't worry because there may not be anything you can do. Tropicals grown indoors in winter, outdoors in summer can probably be expected to look a bit sad in their indoor phase. In cool temperatures (your regular indoor temperature) and not enough light, they will tend to slow down growing or go completely dormant in some cases. Unless you can find or create real greenhouse conditions for them in winter, some leaf anomalies might be expected. High light, humidity and warmth is what makes them grow nicely.

I can't see any evidence of insect or disease damage, it looks sort of like a bit of fertilizer burn (the brown ends) and possibly a leaf that got too close to the grow lights if they are hot?

Even in Florida during winter a lot of the fruit trees look sort of ratty because they're taking a rest. We just tolerate their diminished state and look forward to lush new growth once the weather warms up.

Well, I removed fertilizers sticks from the pots and left my plants in rest phase. Lights aren't too close to plants. I will wait until days become longer and I hope they spread out new leafs. Thanks!

David

Good luck with your plants. I too grow a lot of tropicals (> 20) and they always look like heck after I bring them in. For me in my zone here, it is a real challenge just to keep some of them alive til I can get them back outside in May,

My avocado is looking terrible, but part of that is I cut the top foot off and it is trying to catch its breath.

Hello, David

Well my avocado every week losing leafs, yesterday I saw that my Peruvian Guava started also dropping leafs and lemon tree did the same. Finally,a soon days become longer and longer, I hope these plants will be alive until spring comes.

Avocados loose leaves year round. Mine are a foot deep, but that gives them a soft landing when they drop. As to citrus and guava, they do loose leaves in colder weather, but as long as there are no hard freezes, they will come back in spring.

Thanks, I was really scared about, that after they lost them leafs they won't grow new in spring.

David

Just be careful not to over-water the tropical plants that you bring in. I have learned my lesson multiple times and I tend in general to over-water. Sometimes ones natural inclination when leaves start dropping is to water more. Heh

Well, thats true I have a big problem with fungus gnats because of the result of overwatering. But I water them once a week. Temperature +20-22 C inside.