Bonsai Study Group Forum

General Category => Evergreen Bonsai Discussion => Topic started by: Michael T on October 19, 2009, 01:00 PM

Title: Korean Boxwood
Post by: Michael T on October 19, 2009, 01:00 PM
I'm a little confused. I was reading through an indoor bonsai book that recommends buxus for indoor growth. Seemed very odd to me.

I have a small shohin korean boxwood that I have always wintered outside even in 0f degree temps. I have a high pressure sodium lights in my office with a floor to ceiling windows. I keep one or two of my tropicals in there in a rotating basis.

Was just wondering if anyone thought it would be ok to overwinter boxwood in the office?

In short, does it need a full dormancy period, or are they more akin to tropical varieties.
Title: Re: Korean Boxwood
Post by: Rick Moquin on October 19, 2009, 03:11 PM
There is a cultivar that can be wintered inside, but my experience with boxwoods is that they suffer inside. They are further ahead if left outside where they belong.
Title: Re: Korean Boxwood
Post by: subnet_rx on October 22, 2009, 08:22 PM
I've seen this also, but it was the Box tree and not the boxwood. 
Title: Re: Korean Boxwood
Post by: rockm on October 26, 2009, 08:50 AM
Boxwood is an outdoor species. It is NOT suitable to grow indoors. If you must bring it indoors, do so only for a day, two at the absolute most. Longer and you risk weakening the tree, dropped foliage, etc. Low Humidity levels indoors combined with the plant's dense foliage sets up perfect spider mite habitat. Indoor lighting, no matter how bright the window or overhead lighting is woefully inadequate for any plant. Bright indoor lights are only a tenth as bright as the dimmest sunlight.

The only box that can be grown with moderate to poor success indoors is the tropical variety Buxus Harlandi-and even it is iffy without special task lighting and humidifiers. It is most commonly sold through mallsai vendors, although it's not nearly as common as it used to be. You're not likely to run into it.

Your "Korean" boxwood is Buxus Sinica and is one of the more winter hardy varieties of boxwood--capable of taking Zone 4 winters. It is NOT a tropical species.


Broadleafed evergreens don't really have a dormant period like deciduous species. In winter boxwood slows and ceases growth, but retains its leaves. Protecting those leavs from dry winds and direct sun is important, since both can severely damage the tree in winter time through dessication. Boxwood foliage can turn bronze or even red during extremely cold spells. Bronzed foliage usually isn't severely damaged, but reddish foliage is killed.

I've kept Korean boxwood for years as bonsai. I overwinter them under six to eight inches of mulch in a garden bed out of the wind and out of direct sun. They've done fine for  a dozen years with this treatment.
Title: Re: Korean Boxwood
Post by: Jay on January 13, 2010, 07:10 AM
Greetings, A piggyback question. I have a Buxus Microphylla Koreana Nana. This is its first winter with me. I am overwintering it in my minimally heated sun room. It is in the coldest area and protected from direct sunlight. Do you believe this is OK? It is still green and appears happy.

Title: Re: Korean Boxwood
Post by: rockm on January 13, 2010, 10:32 AM
If you've got the plant inside, it's not dormant. It needs as much light as you can give it, as it is active. The biggest dangers inside are low humidity and too much water.

Go easy with the water. Soggy soil will kill it. Drying out a bit at the roots won't hurt it if it's only for a few hours. It's easy to overwater in the winter, since indoor trees get fussed over in long winter months.

Next winter, if you're in Zone 4 or above, I'd think about leaving the plant outside in a very protected spot or in a cold frame...
Title: Re: Korean Boxwood
Post by: Jay on January 14, 2010, 03:13 PM
Thanks for the info. The tree is inside and as you probably are aware I'm in Zone 3B. I thought about leaving it in my unheated garage by the window, but decided that the sun room would be a better place.
I'll try and add two pixs for your inspection.

Title: Re: Korean Boxwood
Post by: Jay on January 14, 2010, 03:15 PM
OK i posted the second of the two pixs, hopefully here is the first