Hi, Robin!

Easiest: Force a situational dormancy in a cool basement or other location where temps will range from around 45-55*. Chop back to about a foot above the soil. Keep the plant almost dry but don't allow it to go completely dry. It'll will soon shed foliage, or you can snip through the leaf petioles as it dries down.

You'll probably get a little etiolated and spindly growth during winter you can remove in spring. Root prune/repot in spring. Once it gets going, pinching all vines to 2 leaves after they have made 6 leaves for the early part of the growth cycle will give you a much bushier plant with fewer rapidly shooting vines.

Best luck!

Oh - since it's going to need annual repotting - I'd put the plant in the 5:1:1, though it will do great in the gritty mix too.

I bet I'm ahead on frosts at 3-0, eh? ;-)

Al

I just planted a mandevilla in gritty mix last week, and it's doing great so far. (By contrast some of my other gritty mix repots/transplants have been traumatic.) My mandevilla will stay outside year round, though.

Andersons - I'm not saying this in a critical way ..... more like I'm inviting more conversation about WHY there have been traumas - but on another thread so we don't hijack Robin's. It's likely we can figure out where the trouble lies because repotting shouldn't be that hard on plants if a few basic considerations are taken into account. Maybe on the thread I'll link to below - if you're interested.

Al

Here is a link that might be useful: HELP - a click away ....

Thank you both for respinding to my question. I wouldn't consider a discussion of successes and failures after root pruning and repotting into gritty mix "hijacking" my thread. I've been thinking about trying to start such a thread when I have the time to compose it. I've done that with at least three dozen different species in the last five months and would love to compare results with others. My successes (including Bougainvillea, begonia, orchids, amaryllis, ficus, plumeria) have been as surprising as my failures (including avocado, brush cherry bonsai, some clivias). Iv'e been having a really fun learning experience.

Al: I'm curious about why you prefer 5-1-1 for a mandevilla. I grew two in 5-1-1 this summer. The one I bought and repotted in May was healthy with lots of blooms until mid-August, but since then it's stopped producing more than a few blooms and the leaves are turning yellow. I used Osmocote plus and agricultural lime in the original soil mix and I've been fertilizing weekly with MG 24-8-16 since July 1. I bought the other Mandevilla in late July on sale and had to prune it quite a bit to get it out of it's original pot. I knew it might not bloom this year because of my pruning, but thought it was worth nurturing because of the few blooms it had. Since then it's grown like gangbusters, which is why I want to overwinter it. Two plants of the same species are showing different results in the same 5-1-1 mix. I was thinking the one that's so vigorous might do better in gritty mix over winter, especially since I don't have a place to put it where I can keep the temps much lower than 55.

I usually use the gritty mix for all my woody material, with the exception of those few plants so genetically vigorous they're sure to fill the pot with roots yearly and need full repots as often. For those plants, I would choose the 5:1:1 mix - just because it's less expensive & easier (to make) than the 5:1:1 mix.

I bet you could prolly over-winter it in your garage, if you set it on the floor & cover with an over-turned cardboard box so the soil doesn't freeze.

I have the same issue with 2 Styrax japonica (Japanese snowbell) shrubs I lifted from the nursery beds to start training as bonsai in spring of '09. Both plants are genetically the same (started as cuttings from the same plant) and both are in the same type of container and in the same soil (gritty), yet one of the plants has put on twice the mass the other has during this, the second year in the large pots. Perhaps I'll find some reason when I repot in the spring, but until then it will be a mystery. I know there's no answer in what I related, but at least you know you're not alone. ;-)

Fare well, Robin.

Al

I guess I spoke too soon...this week, my mandevilla newly transplanted into gritty (no root work) has LOTS of yellowing leaves low on the bush. New leaves on the tips of stems are small and soft. There are new blooms however. Does it need more nitrogen?

Also I don't know if this was related to the transplant, but there's now a stem that shot out about 12" with no leaves, then has a few leaves and blooms on the very tip. !

What kind of soil was it in prior to the bump?

Al