I pruned off a dead top on mine, lost in a late freeze (it's still about 12 feet tall), did it kind of late, well into the hot weather. It did fine and branched out nicely. Made sure it was adequately watered. Is it in direct sun? Mine is on the patio up against the house with a southern exposure, it gets sun but not all day long, it's a little protected in the afternoon.I had one in the ground on the west side of the house which seemed a little too harshly sunny.

Mine sits on the front porch facing the west, so it gets the afternoon sun, but its been there for a couple of years now and it seems to be growing good. Its just so big now that I can't bring it in anymore in the winter and the cold has caused it to lose its lower leaves. My hope is to prune it down low enough to stimulate new growth on the lower parts of the plant, so that its lower parts won't be so bare.
Its already got a few branches coming off the base and main stalks, but I'm not sure if there is enough growth to feed the plant if I prune the main stalks below the level of their leaf growth.
By doing so, the plant will for the most part be bare, except for the few small branches down low.

If you prune it back it will have less mass to support and the root system will put energy into the new growth, so having fewer leaves might not be an issue but I think I would start with cutting back just a third of what you think needs to come off and see how it responds. For winter freeze protection we spread a big canvas paint drop cloth on the ground and then lower the plant onto its side. We then wrap the drop cloth around it and its pot like a swaddling. A towel over the surface of the pot before tilting it down can keep any loose soil from tipping out. We only do this when a freeze is predicted. It stays outside year round and seems to acclimatize as the weather grows cooler. If laying the plant down isn't an option you can drape flannel sheets around the pot and as much of the plant as you can reach and secure the sheet ends together with clothespins. The upper part of the plant may freeze but the lower part and roots will remain alive if well protected. Then in the spring you can tell where the dead stops and the living tissue begins, and prune back to living tissue. Mine branched back nicely. We haven't moved our huge rubber plant but one time in the past five years and that was to drag it into the garage because a hurricane was coming and we didn't want it to become a projectile. We have also successfully protected large potted Queen palms with the lay down and swaddle method. We just cut our rubber tree back about a third because it had become so tall that strong winds would blow it over and our other smaller plants would get crushed. I love rubber tree plants and hope yours continues to do well!

That was going to be my alternative option if I didn't receive any possitive responses on my first option. My only concern with doing that though is upper branching and the plant still being mostly bare down low. I want to see some lower branching too if at all possible, in order for the plant to be fuller.
My rubber tree normally acclimates well too. I believe part of the reason that it lost its lower leaves this past winter is because of my own neglect. I should have re-potted and pruned it last growing season and failed to do so. The soil got packed too tightly and it was also root bound. Also, the main branches were laying over a little too much, so I should've pruned it to strengthen them.
Your suggestion is probably the route I will take, in order to be safe.

Thanks,

BTW...Your rubber plant must be beautiful...12 feet tall is huge. How long have you had it? And how do you maintain a tree that size (prune, re-pot, etc...)? Also, what size pot do you have it in?
I would love to see it. Can you post a picture of it?

I will see if I can teach myself how to post a pic. I am a consumer of tech but definitely not tech savvy, LOL. Re-potting only occurs every few years when we know we have lots of time so size is controlled by pruning, usually once a year or whenever it starts to look ungainly. I'm sure the soil is compacted and there is root binding but we just keep feeding and watering it and have periodically top dressed with fresh potting mix. The pot is big but I can drag it with determination, otherwise I need husband help. I did want to let you know that if you already have some lower new branches, I think that is a sign that pruning would not be harmful because the roots that feed the stem to make new branches are good. Let me see about how to post...

* Best time to do extensive root work (repot) is between Father's Day - 4th of July. Be sure your repotting is done before the last week of July to make sure your plant has time to recover before winter.

* Do your pruning AFTER you repot - usually 2-3 weeks. The tree's ONLY source of food is it's leaves (and what little it can produce in green stem tissues). Leaving the leaves on the tree until the plant has recovered from the repot is the fastest way to get the plant back on its feet.

* Tight roots causes shedding of lower/older foliage, and leaves the tree with foliage concentrations near apices (growing branch tips). No amount of fertilizing, watering, or other cultural care will correct the problem - only remedying root congestion will restore the plant's ability to maximize foliage mass.

Rubber trees can't adjust to low temperatures. Once the temperature drops much below 60-65*, the plant's ability to carry on photosynthesis is seriously compromised. This means the plant goes from living on energy from the sun to battery power, relying on its stored energy reserves. So, at temperatures below 60-65*, no matter how the plant LOOKS, it's going to be in steady decline until it gets warmer temps and enough light to allow the plant to function as it's genetically programmed to.

Al

Is the plant's capacity to support its unpruned upper compromised at all by any root pruning that takes place first?

"Winter" here on the Gulf Coast is relative, really just a series of cooler days followed by warm ups into the upper 60's and even lower 70's, which probably explains why my rubber tree seemed acclimatized. It was really just getting booster feedings from the warmth and sun in between the "cold" fronts.

I'm envious of August in more temperate climes, but not in January!

>> Best time to do extensive root work (repot) is between Father's Day - 4th of July.

Al, is this applicable to other trees or to other plants in general? I grow tropicals indoors with no direct light all year round. Does someone's zone affect this best repotting window?

Thanks for being so active and helpful on this forum. Much appreciated.

Is the plant's capacity to support its unpruned upper compromised at all by any root pruning that takes place first? Yes, it is. To some degree that can be offset by siting the plant in the shade and keeping it out of the wind. Also, if you're repotting from a water-retentive soil to a well-aerated soil, the improvement in root function and the number of fine roots usually becomes quickly evident & additionally helps the recovery. If, for instance, you have a healthy 3 gallon tree and you reduce the roots by say 75%, you might need to remove a substantial volume of foliage to prevent the tree from seemingly indiscriminately shedding what it can't support. It's better to select the branches that don't compliment your vision for the tree's design than to let the tree decide. Also, you can partially defoliate if you remove a LOT of roots and the tree will quickly replace lost leaves as soon as the roots' ability to keep up with the canopy is back in balance. Everything revolves around the roots - the roots have to be able to support new growth before it can occur.

>> Best time to do extensive root work (repot) is between Father's Day - 4th of July. Al, is this applicable to other trees or to other plants in general? I grow tropicals indoors with no direct light all year round. Does someone's zone affect this best repotting window?

Plants have internal clocks (search "endogenous rhythm" and/or "circadian rhythm") that tell them when they are supposed to grow. I keep all my tropical trees (about 75 of them) under lights in a basement grow area. There is only one window at the far end of the basement, so it supplies no usable light. Somehow, the trees know when the vernal equinox is eminent and begin to exhibit more vigorous growth, despite the only usable light they get is artificial and on a 16/8 schedule.

I don't think the Father's Day - July 4th rule of thumb is nearly as important if your trees were outdoors or living on sunlight, but I'd still say that even if there were no changes in artificial light intensity/duration throughout the year, that the time frame I suggested would still be the best time. If your trees grow actively all year and they're healthy under artificial light, repot any time you have a mind to. The most significant effect of that sort of 'out of season' repotting would probably be a little longer recovery before active growth can resume. For trees that AREN'T healthy, the timing is a more significant consideration.

I don't think a growers zone affects the best window much, but I would say that the closer to the equator you get, the wider the window becomes. In consideration of the best timing, I have a much narrower window than someone who lives in south FL or TX. Growers in those locales can repot with fast recovery anytime in Jun or July, and the effects of repotting in May or Aug - mid-Sep are much easier on the plant than they would be closer to the 40-45th parallels.

Al

thanks, Al, very helpful.