Winter growing / storage

[David_Sweden]

I am hoping to hear about your experiences of how to handle palms indoors during the winter. I know that even those who don't grow palms indoors year round like me, often take them indoors in the winter. I can also imagine that some are more sensitive than other.

I have read that if I keep the temperature high (~22C/72F like my flat normally is), many palms might produce lanky and distorted growth. So I'm thinking of lowering the temperature as much as I can, and/or adding artificial light. One advantage of lower indoors temp would be that humidity will be a bit higher, but if it's a really cold winters day I don't think a few degrees lower will help much.

I have palms at two spots: At the windows of my balcony (SSE), and in an oriel (NNW). In the oriel I have a Rhopalostylis baueri (1½ m), Kentia Palm (1½ m), Licuala Ramsayi (~1 m), Licuala peltata var. sumawongii (~½ m) and a Chamedora Elegans (~20 pcs, 1-3 dm) (and a Jatropha podagrica and Japanese Pepper Tree bonsai). At the balcony I have a Foxtail Palm, a Lipstick Palm, a Livistona rotundifolia and a Phoenix roebelenii, all small (1-5 dm) (and a "Hawaiian Palm").

All palms in the oriel except the Kentia and Baueri are behind a screen made of white lace which lowers direct sunlight by 50% so that it is at most 20-35 klx. I might be able to remove this screen in fall or spring except for the Ch Elegans. (Note: Everyone says Kentias dislike direct sun but this one loves the ~3 hours of evening sun.) Most palms have been here since april, the Kentia is older, ~10 years. Most have been growing quite good: The Roebelenii has added one frond per month, the Rotundifolia one every 2 months, the Baueri only one but a giant one ~1½ m, and that's all average growth, it was slower in the beginning. The only one that is very slow is the Lipstick palm but so far I'm happy it's alive, it didn't like the cold transport here among other things.

The oriel is right in the living area (next to the kitchen table) so I can't lower the temp much, but at least I can shut down or mimimize the radiators in the oriel, and that way maybe get down to about 20C/68F. I have read radiators are liable of causing brown tips, but one thing I haven't heard mentioned is the effect of the cold downdraughts from the windows, which the radiators actually might counteract. Some palms hate cold draughts. My plan of handling that is to move them at least 1 dm from the windows, maybe 2 dm if possible but I doubt there is enough space. I know that 2 dm distance lowers the light level quite much on an overcast day though, so I'll probably aim for ~1 dm.

The balcony is in my guest room, I think I can lower the temp to about 18C/64F there most days.

I'm thinking that I will have to decide on what level of light to aim at, something between 1-10 klx is easy to get from artificial light and resembles bright shadow. I think I've read that e g the Kentia and Roebelenii will survive winter fine if placed close to a window. I can imagine that e g the Kentia might decide to drop one of the lower fronds? If so that would be a pity since it's grown much more than ever this year due to me getting better at taking care of it, so if possible, I would like to aim at it (and all of them) having enough light not to get any brown fronds during the winter.

So I guess the main question is: With the temperature conditions I can give them, what light level should I aim at? I'm planning on getting some quite ample artificial lights if required. I'm quessing that as long as I don't go above ~20 klx there are no downsides with plentiful light? I also plan to make sure all leaves get 1-10 klx (at least 0,5-20 klx) which is a bit of a challenge, I can imagine with artificial light some leaves often get almost zero light. And I plan to leave the lights on for 14h/day. It would be nice if the palms kept on growing all winter (but slower of course). Or is it for any reason better to aim lower, so that they survive ok but don't grow? I also wonder about experiences specifically for all these palms (or if you want to give this thread a more general coverage then go ahead and add info on all palms you know of).

Regarding humidity I am planning to make some special efforts on the really cold days (like shutting down ventilation for 16h per day those days and getting a humidifier ur just boil a lot of water on the stove), we usually get very few days lower than a few degrees C. And I will keep misting them every morning, even though no book I've seen has any clear evidence if that helps or not, but that's a different discussion. I have a hygrometer and have already concluded e g pebble trays or even humidifiers have no effect unless I shut off ventilation completely, which I shouldn't do for prolonged periods.

So far humidity has usually been 45-55% and they all do ok (with 1-2 mistings per day, one of them on both sides of the leaves). Will use incandescent or LED, and monitor soil moisture level. And I plan to continue water them thoroughly but not until they are barely moist (or keep a bit more moist for the ones that usually live in swamps). Will keep an eye on my hygrometer and forecasts. Will leach soil 2-3 times per year. Might get RO filtered water but I'm not sure if there's any point in using it for watering as well or only for misting.

Some other threads I found on palms indoors in the winter, related but not exactly the same subject: 1 2 3 4

The last thread mentions anti transpirant polymer spray, which I never heard of before; googling gave me this PDF which seems to say such sprays have little or no effect. Have anyone else tested this? I also wouldn't know where to buy it in europe.

But mainly I'm interested in your experience in what combos of temperature and (artificial) light that works well (for my species).

[David_Sweden]

Bump! No one has any experience to share on winter growing / storage? I see I forgot to mention "indoors" in the heading.

So far I've found info that says palms in general can be put in a dark corner all winter with no harm (but others that say either that if at room temp they should have light, and that all fronds need light or else they may look like crap in the spring), seems to me this might well differ between species?

I think it's time to get a grow light within a week or two since it's getting noteably darker now. My main idea right now is to aim at:

• At the balcony: 20 klx, two groups about diam ½ m, using two 35W lamps per group
• In the oriel: 5 klx, two groups about diam 1½ m, using two 70W lamps per group

LEDs don't have enough power and I want the lamps 1-3 m away to make it look good and avoid heating, so I need reflector lamps and that means no fluorescents. I found these relatively new Philips Ceramic metal halide (CDM) 4200K that seem good both for the plants and me. Ordinary Metal Halide are not cheaper (and very blue). I suppose I could use HPS since they might be cheaper, and I read palm are not prone to elongation even in their yellowish light and my main plan is to also give them daylight. The bushy ones I will turn 1-2 times per week, the other ones I think will do ok due to 2 lamps in 2 angles plus daylight.

How does that sound? I'm hoping that will make them grow at a moderate rate.

[michigan steve]

I keep my palms out as long as i can, even when i start to see frost i just move the big ones next to the house and cover with a frost blanket over night and i bring all the small ones in. I put everything back out the next morning.

When i bring them in for good they are all put in one room with extra lighting.

[Mauna Kea Cloudforest]

You're posting in the wrong forum, try the hardy palm forum. You will get much better responses.

[David_Sweden]

No I'm not interested in cold hardiness since I'm indoors and I think that's the only other forum is about cold hardy palms.

It would be nice to create a subsection especially for indoor palms, I don't know how many that would be interested but I know of a few.

Anyway I have to make a decision very soon so that I have light within a week or two and it will probably have to be shipped from abroad which probably takes at least a week..

[sashaeffer]

I have around 135 palms, some in the ground year around but all the rest come either inside or in a garage that never drops below freezing.

I have a heat pump so it doesn't dry out the air like forced air furnace does(although I have that as a back up) So, I can keep humidity around 45%. I keep inside temps at 68deg F. That temp and humidity levels keeps most plant pests away as well.

I back off watering quite a bit and let them be more on the dry side other than a few that have to stay wet all the time. Most are in a room that faces East with 3 large floor to ceiling windows. Others are in a West facing room with one floor to ceiling window.

My wife HATES it when I bring all the palms inside. "It' looks like a Jungle in here!" she snorts (exactly the look I was after)

Let me know if you have any other questions.

Scott/ Omaha, Nebraska USA 6B zone

[Alcibiades]

Hello David,

Most Palms do ok with 20C indoor. Don`t wait too long before bringing them in. Install some small ventilators to get some air movement especially close to radiators. Try to increase humidity. Maybe you can install an air humidifier? Aerate your rooms regularely but keep sensible palms like cyrtostachys away from draft. Forget about the artifical light. To do this effectively you have to install two 600 Watt lamps with a reflector to light 2 square metre. Not to mention that such a setup somewhat disturbes social life in your living room. Spray your palms if possible twice a day and dont forget the bottom side of the leafs. Reduce fertilizer during winter to a minimum.

Edited August 31, 2014 by Alcibiades

[ghar41]

Temperature and light have never been a problem for me with indoor palms...temperatures comfortable to humans is fine for most palms and some light is required. I would not move them to a dark corner.

The problem i have every year is a lack of moisture in the air due to the drying effects of my furnace in warming the house. I would say this is the most common problem among indoor palms.

[Mauna Kea Cloudforest]

No I'm not interested in cold hardiness since I'm indoors and I think that's the only other forum is about cold hardy palms.

It would be nice to create a subsection especially for indoor palms, I don't know how many that would be interested but I know of a few.

Anyway I have to make a decision very soon so that I have light within a week or two and it will probably have to be shipped from abroad which probably takes at least a week..

The cold hardy forum is for growing palms in a cold climate like yours, it's not restricted to growing hardy palms. There are nay people who grow tender palms in very high latitudes. If you guys have that attitude about your own forum, it's never going to take off. It's pretty dead in there these days.

[David_Sweden]

Thanks for the useful info.

Bahrea, create a forum for indoors growing (or container growing) and that's where I'd most often be. The one you call "mine" is named "cold hady palms", that means it is all about growing outdoors, mine never see less than ~20C i e 68F. And this particular question also relates to those who grow outdoors in containers and move them in during the winter, which also isn't cold hardy palms or they could leave them outside, so this is a good question to post in a general forum.

[sashaeffer]

^^^Agreed. Container grown palms would be nice add to forum options. Not everyone lives where it barely gets to freezing in the Winter so grow most of their palms in pots.

[sashaeffer]

David sent you PM

[Alcibiades]

I second that. A subforum for us weirdos who grow tropical palms in zone 6 would be nice.

I always appreciate to read discussions about heavy freezes from guys who can plant cocos nucifera in their gardens. But growing indoors in pots in a hostile climate is something different and has nothing to do with the actual cold hardiness of the palm. Asking about my Cyrtostachys renda in the cold hardiness forum would feel kind of silly.

[David_Sweden]

I started this topic on suggesting a forum for indoor and container growing:

http://www.palmtalk.org/forum/index.php?/topic/43034-indoor-container-grown-palms/