Wow. Nice article. Makes me nostalgic for my days in Arizona...

Keeping western junipers here in the East is problematic. The climate is very different. Heat and humidity are the culprits, I suspect. The desert is not a swamp as most of the eastern coast is. The heat is different here. In D.C. (a former swamp drained to construct the city), temps may only be in the mid 90's on a hot summer day, not really the hellish 110+ the desert can reach. However, the humidity can also be in the low 90 percents too. That doesn't allow for alot of respiration. Humans can't sweat effectively, neither can plants respire as effectively.

There are news stories every summer here noting that a tourist from out west goes jogging when "it's only 90," only to collapse from heat exhaustion 30 minutes out.
The higher humidity levels can lead to difficulties in growing bonsai if you're not attentive. High humidity means water stays in the rootball alot longer in bonsai because they're not respiring it through their leaves effectively. It's possible to drown a bonsai with overwatering in the summer, even if you're using a thoroughly draining soil mix.

Too much water, not enough respiration can stress trees out over time too, even if you are attentive to watering. The local trees sometimes enter a summer dormancy, where they just shut down active growth for a few weeks in the hottest part of the summer. That can also lead to more water accumulation in the rootball if you're not aware of what's happening. Watering has to be adjusted accordingly.

Sorry for the longwinded response.

Great article. Keep this kind of thing up.

I was re-reading Nick Lenz's book on Rocky Mountain Junipers, and note that, in addition to the forementioned humidity, acid rain is also a problem to the point where he recommends adding ground limestone to the soil after a "heavy bout of acid rain". (Nick is writing from Massachusetts.)

He goes on to say:

"In the evening of a dessicating day when I water the larch or white cedar or apples, I make repeated passes to saturate the soil. With pitch pine, I make a single pass. With established Rocky Mountain Junipers, I water the grass beneath them and let them smell the resulting humidity."

He also points out that they "will never settle down to the original dense mature foliage of the dry mountains, but their juvenile foliage is tiny-needled and quite attractive. The growth is somewhat awkward for classical bonsai training, but can be manipulated."

I'd urge anyone considering trying to grow these in the East to read the 4 pages of Nick's book that discuss them.

As for California Junipers in the Northeast, that's a non-issue. It's too cold as well.

Don't think cold is a problem for most desert juniper species. It gets cold in the desert, colder than Mass. sometimes. Arid air doesn't hold heat and cooling is rapid and dramatic in the desert. If you look at the USDA hardiness map, zones 5a and 5b are common in the Southwest, although not in SW California...

Very interesting article Al.

Rocky Mountain Junipers do extremely well in my garden. I use very well draining soil, water every day a lot, leave the trees out when it rains for two weeks in a row, leave them on the spot all winter, with or without snow, feed agressively from April to October , mainly organic.

Everything the contrary of what they told me in America. Americans coming to my garden just cannot believe the health of my RMJs, Ponderosa pines just the same.

Very mature growth on the morey.

Another bonsai myth.

Attached Images

	Dscn7920v.jpg (63.5 KB, 186 views)
	Dscn8260v.jpg (64.3 KB, 213 views)
	Dscn9071v.jpg (62.2 KB, 210 views)

"Everything the contrary of what the told me in America."

With due respect, that covers an awful lot of ground and alot of that advice might be accurate here. America is 20 times the size of Germany, with many more climates. What works for you might not work for the majority of folks here, especially if they live in the South. where heat and humidity are higher.

In a brief search of the web, I found that the average July day temperature in Washington D.C. is about 87 degrees. The average July day in Munich is around 75 F. The relative humidity in both regions was about the same. However the "heat index" effect that combines temperature and humidity's affects on human perspiration (plants also respire water) are dramatic.

An 75 F degree day in Munich with relative humidity of 80 percent might yield a heat index of almost 80. An 87 degree day in Washington D.C with relative humidity of 80 percent yields a heat index effect of 113 F. Eighty seven is an average here in D.C. We get much higher temperatures in July and August. A few summers ago in July, we had a string of almost 30 days above 90 degrees. Days in July and August over 100 F are hardly rare. Temperatures and humidity levels in the deep south rise even higher and that region can gets an enormous amount of rain.

rockm,

I did not adress your post really. It was what Thomas Bart wrote which reminded me so much of what I was told about RMJ and Ponderosa pines. I would never judge what it means to grow them in DC area or Florida. but New England area and similar is quite comparable to central Europe.

I agree with Walter wholeheartedly. Here in New England, we were always told that RMJ and Ponderosa Pine didn't last long due to our high humidity and rain levels. Working with both these species for over 10 years now, I have found that they thrive here. Nick is right that the foliage is different on the RMJ (but certainly desirable).
Regarding Ponderosa Pines, I know of no one who has had luck with needle reduction though (has anyone?). Walter speaks of cutting needles - this is common with Ponderosa. Right now I am working with 3 collected shohin sized Ponderosa Pines (a crazy proposition, I know!). One of them does have a much shorter needle but i believe it is due to the stress it experienced while growing - as it gets healthier, I expect them to get longer.
Now with California Juniper, I have seen mixed results. There are a few at New England Bonsai Gardens that have been thriving for almost 10 years now so it can be done. I have just not personally tried them here yet. I have one that I got last year but that does not afford me enough experience to say one way or the other.
John Romano
bunjingi@aol.com
Rhode Island, USA

Well, it seems it strayed a bit away from Al's story on collecting CALIFORNIA JUNIPERS and Charles susequent query on growing them in Florida , but,

Charles,
RockM might have better info on this , but, I believe they lost at least one of the Ca. Junipers in the national collection due to too much moisture ( Is that true RockM?) and I have seen them, during PBA shows, with covers over the pots when rain was happening or about to happen.
As for RMJ's, I know Miami Tropical has had a big'un for a few years now. Can't get much hotter or humid in Florida than there! I wonder how long it will last.?

BTW, I was "Taken" with the sage for sale and in workshops at Denver ABS convention in '97 and brought two collected ones from Arizona home for myself and my business partner, ALONG with the warning of too much water and humidity. well...
I could almost watch them turn brown!!

All in all, unless you have "Special care areas" I recommend people stick with trees that grow within a couple zones + or - from theirs. They grow better, look better and you'll be more successful with a tree that isn't always "on the edge"
Regards,
Dale

Walter: I'm not about to get into the middle of a debate between you and Nick. I defer to you both.

Having said that, it is my impression based on three trips in August, that it is less humid in Bavaria during mid summer than here in New Jersey. I would also say that it seemed that the climate around Munchen was different (warmer) than that in the Fichtelgebirge (Bischofsgruen), where I spent most of my time. I'll leave that to the keepers of the almanacs to confirm or deny.

Bart Thomas

I'm looking forward to seeing you in Washington.

The National Arb has had continuing troubles with collected Cal. junipers in their bonsai collection (RMJ too, but to a lesser extent) from what I've heard. They apparently don't up and die in a year or so, but decline over a period of years. I have avoided adding western species like this to my collection for this reason.

"Non-native" Southern species, like bald cypress, live oak and the like (which are only one or one and a half zones away from us) fare much better in this climate than western ones. The issue with much of the middle Atlantic states (New Jersey to Northern N. Carolina, but esepcially the N. Va./Md. D.C. area) is that they're in a transition zone between Northern climate zones and Southern ones, we get the benefits of both--longer growing season, moderate snowfall, but we also get the worst of both--wet winters where temperatures can drop below zero F and summers with strings of 90-100 degree days with stifling humidity.

As Walter points out, the RMJ (And most likely other western species) can, indeed, thrive in moister areas with lower summer temperatures and moderate humidity levels. But the hotter and more humid the climate, the more problems you will probably have with these species. If any of these species could establish and sustain itself in other climactic areas in the U.S., they would be native there. They don't grow east of the Mississippi river for no reason.

P.S. Undoubtedly someone will point this out, so--No. I have no direct care experience with RMJ or Cal. junipers as bonsai. I do have direct knowledge, however, that qualified horticultural experts at the National Arboretum have difficulty with them here. I've seen a decline in many of the western collected species in the collection over the last ten years or so--sparser foliage, dropped limbs and trunks, etc. It's not a catostrophic decline for most, but it's noticeable.