How to check soil for watering

[William Dinitzen]

An important point is to water your trees well before putting them under the mulch. Then water the mulch as you add it. Dry mulch will pull moisture from the soil in the pots. Also make sure there is space under the pot before mulching--I put my pots on bricks to keep the bottom surface off of the ground. Once all that is done, I rarely water anything. The mulch pile stays moist from rain and winter precip. Snow is excellent. Don't worry about it. You can check the mulch every so often by digging down into it to the pots to see if it's moist, then cover things back up. Below are some of my trees in mid-winter a few years ago.

Great, I think I have an idea of everything I need to do for winter then, I really appreciate you taking the time to respond.

 

[William Dinitzen]

An important point is to water your trees well before putting them under the mulch. Then water the mulch as you add it. Dry mulch will pull moisture from the soil in the pots. Also make sure there is space under the pot before mulching--I put my pots on bricks to keep the bottom surface off of the ground. Once all that is done, I rarely water anything. The mulch pile stays moist from rain and winter precip. Snow is excellent. Don't worry about it. You can check the mulch every so often by digging down into it to the pots to see if it's moist, then cover things back up. Below are some of my trees in mid-winter a few years ago.

 

[eugenev2]

@rockm, interested in this chinese elm dormancy comment, how long will they survive without going below 40F to enter dormancy?
My reason for asking is, they are sold quite frequently here and tend to be almost completely green throughout winter as our winters rarely go under 40F, we get at most 10 days at either 40F or below and the rest averages between 50 to 59F.

 

[rockm]

@rockm, interested in this chinese elm dormancy comment, how long will they survive without going below 40F to enter dormancy?
My reason for asking is, they are sold quite frequently here and tend to be almost completely green throughout winter as our winters rarely go under 40F, we get at most 10 days at either 40F or below and the rest averages between 50 to 59F.

Have a few questions for you--How many indoor Chinese elms are there in South Africa? How many live past five or six years? You also have shorter daylength in winter compared to summer by about four hours, correct? Chinese elms "tend" to be "almost completely green" in winter? sounds to me like there is some form of dormancy going on to me.

 

[Paradox]

@rockm, interested in this chinese elm dormancy comment, how long will they survive without going below 40F to enter dormancy?
My reason for asking is, they are sold quite frequently here and tend to be almost completely green throughout winter as our winters rarely go under 40F, we get at most 10 days at either 40F or below and the rest averages between 50 to 59F.

@rockm might have better insight about chinese elm, but they have a very wide temperature tolerance compared to many trees and may be a species that can get dormancy slightly higher than most temperate species

*edit* and he posted just before I did...

 

[rockm]

@rockm might have better insight about chinese elm, but they have a very wide temperature tolerance compared to many trees and may be a species that can get dormancy slightly higher than most temperate species

*edit* and he posted just before I did...

Chinese elm is "semi-deciduous" in our southwestern deserts and south. That doesn't mean the tree is actively growing. Live oaks and other trees follow similar strategies of not dropping leaves in winter. They're not actively growing, however and it doesn't get past the dormancy thing, or make them suitable for reliable indoor culture.

 

[Paradox]

Chinese elm is "semi-deciduous" in our southwestern deserts and south. That doesn't mean the tree is actively growing. Live oaks and other trees follow similar strategies of not dropping leaves in winter. They're not actively growing, however and it doesn't get past the dormancy thing, or make them suitable for indoor culture.

I agree they are not suitable and shouldn't be kept indoors.
I am wondering since the do have a much wider temperature range than most temperate trees, if they can achieve dormancy at a higher temperature than 40 deg F? My BRT and ficus go through a semi dormant period in January and February. They don't lose their leaves abut they don't grow either until some time mid March, They are not getting to temperatures as low as 40 in my basement but they do stop growing for a couple of months. If 1000 hours is a standard minimum for all trees, that is 41 days and would fit with the time requirement.

 

[rockm]

I agree they are not suitable and shouldn't be kept indoors.
I am wondering since the do have a much wider temperature range than most temperate trees, if they can achieve dormancy at a higher temperature than 40 deg F? My BRT and ficus go through a semi dormant period in January and February. They don't lose their leaves abut they don't grow either until some time mid March, They are not getting to temperatures as low as 40 in my basement but they do stop growing for a couple of months. If 1000 hours is a standard minimum for all trees, that is 41 days and would fit with the time requirement.

The species is adaptable (it's so adaptable it's considered invasive in a dozen states). It's natural range is China, Korea and Japan. However, it grow better in some places than in others. The Iowa Dept. of Natural Resources has a PDF (Which I can't link to for some reason) that says it's hardy in USDA zones 5-8, but "tolerates"4-9."

 

[Ian_P]

Is there certain mulch you recommend? Or more importantly certain mulch to stay away from?

 

[rockm]

Is there certain mulch you recommend? Or more importantly certain mulch to stay away from?

Shredded hardwood mulch is what I use. Stay away from chunks or "nugget" kinds of bark mulch. Looks like this:

 

[rockm]

The species is adaptable (it's so adaptable it's considered invasive in a dozen states). It's natural range is China, Korea and Japan. However, it grow better in some places than in others. The Iowa Dept. of Natural Resources has a PDF (Which I can't link to for some reason) that says it's hardy in USDA zones 5-8, but "tolerates"4-9."

Also worth noting the states that list this species as invasive (DC, NC, NE, NJ, VA, and WI) all experience cold winters. Since invasives grow best in conditions that favor them, that might be an indication of optimal dormancy requirements

 

[eugenev2]

Have a few questions for you--How many indoor Chinese elms are there in South Africa? How many live past five or six years? You also have shorter daylength in winter compared to summer by about four hours, correct? Chinese elms "tend" to be "almost completely green" in winter? sounds to me like there is some form of dormancy going on to me.

Ja look, every person that i know that has kept their chinese elm indoors here for prolonged periods of time, had a dead tree eventually. I cannot speak of bonsai Chinese elms that are older than 5 years, but there are garden trees (cannot confirm if they are chinese elms tho, but they look similar) that are 25 to 50 years old and older. But basically i hope @Paradox is correct that the range is slightly higher, as i've gotten fairly attached to mine, i hope to have it for much longer than 5 years

 

[dbonsaiw]

First, outside weather is NOT a problem for temperate zone trees. Rain isn't a problem--drainage is the problem for trees in containers. That means when it rains for two or three days you can prop one edge of the pot up on a brick, so the pot slants to one side. That will increase runoff. Other than that quit worrying. Trees have been rained on for a very long, long, long time.

Yes the greenhouse covering is a problem even if it has one end open to air. It promotes mold, wet conditions and general unhealthy plants. Temperate bonsai require a lot of air circulation, as in breezes and actual WIND. That keeps them from developing all manner of bacterial and fungal problems. Get them out from under that cover. They don't need it, it's potentially a problem.

As for winter storage, I simply mulch my temperate maples, elms, oak, bald cypress into garden beds cover them in their pots with five to six inches of shredded hardwood mulch. I make sure the pots have drainage space underneath before I bury the pots. I'm in USDA Zone 7--which has -17 to -15 C average minimal temperature. Denmark appears to be a bit warmer than here, but I'm not sure. If it is or even equal to what I have, your trees, including the elm, will be fine with similar treatment.

BTW the open bottom doesn't allow cooling. It actually encourages heating, since warm air rises, cold air sinks. So you're trapping hotter moister air for the plants. Warmer moist environments are hothouses for all kinds of problems.

This is great advice and I've been following Rockm's lead on this with success. My first year with bonsai was a little rough as I didn't really know anything, was constantly worried about everything and ended up doing things that basically left me with nothing at the start of year 2. This includes mold and related issues from keeping trees in a tent. Rockm's advice was like a Xanax. Not 100% on the weather in Denmark, buy here in NY the trees are perfectly fine through the winter outdoors and buried in mulch. I believe the trees really appreciate consistency in pot temps, especially avoiding the constant freeze/thaw cycles. Frozen is fine. Thawed is fine. But cycles of freezing and thawing are not.

 

[dbonsaiw]

Here's what my mulch pile currently looks like (I probably jumped the gun and did this early). When we start getting freezing temps I will cover the whole pile, including the pots, with mulch.

 

[eugenev2]

This is great advice and I've been following Rockm's lead on this with success. My first year with bonsai was a little rough as I didn't really know anything, was constantly worried about everything and ended up doing things that basically left me with nothing at the start of year 2. This includes mold and related issues from keeping trees in a tent. Rockm's advice was like a Xanax. Not 100% on the weather in Denmark, buy here in NY the trees are perfectly fine through the winter outdoors and buried in mulch. I believe the trees really appreciate consistency in pot temps, especially avoiding the constant freeze/thaw cycles. Frozen is fine. Thawed is fine. But cycles of freezing and thawing are not.

I think dbonsaiw touches on something here, first prize is joining a bonsai club or getting in touch with someone locally, they usually have more climate specific help for you. Here is the second best place, for my climate for example Shibui's information is normally spot on or as close as you can get

 

[Crash607]

Someone recently suggested that a good method for checking for moisture level in your bonsai is by sticking a wooden or bamboo chopstick in the soil. You can pull it out if you're not sure and it acts as a sort of "dip-stick". If this stick is wet, your soil doesn't need watering.