water requirements for winter will drop (as you'd expect)
fertilizers....I'd say it's too late in the season, especially for any nitrogen
next spring (at leaf-out) you can easily see where to prune, and at that time, fertilize and/or repot

Don't fertilize now at all, the allamanda will die back to the soil line as we get freezes here in Central FL.

It will survive, thought, and re-emerge next March. That's when it'll need lots of sun (to flower) and when you can fertilize.

I just purchased one of these this weekend at a local nursery here in Zone 5. The 'expert' on hand suggested that it will be fine outside if planted beginning of June, and will grow vigorously to 4x it's current size (1 gal pot- about 1' x 1' at the moment).

She said it will NOT survive outside in the winter months here in NH, and to bring indoors for the winter. My question is: I guess I have no problems with it being 4x it's current size THIS winter to bring indoors, but is it going to grow like that EVERY year? What can I expect for growth in future years?

I'm thinking I may have made a hasty decision on this one, and it won't be a practical choice for this area.

Keep the Allamanda in a container bigger than what you have it in from the store... a nice large one that you might put a small indoor tree in then bring it indoors and trim it back drastically. Then in the spring bring it back out and you can keep it under control. Allamanda can get extremely large especially if it doesn't freeze back like the area I live in.

What is the best way to trim the bush to keep the bush LOW AND FULL. We have them in a planter in front of our mobil home and want them to fill in.

I have several bushes but two of them are yellow in the leaves - I water every day - what is going on with the two that are yellowing?

is it poisonous?

There's no way that we can tell what might be causing the yellowing, Judy, but I will say that one of the most common causes of this symptom is overwatering. Look into it.

Allamanda, if ingested in large quantities, should be considered toxic. It's not the MOST poisonous plant in your yard, in all likelihood.

My Alamanda bushes got some kind of a fungus that I had treated by a landscape company. What used to be lush and full of flowers are now sticks and a few leaves. I do see some regrowth, however. I live in SW Florida and they get all afternoon sun. Is it too late in the season to fertilize or can I use Miracle Grow now?