Saturday, December 18, 2010

greenhouse in winter


Nik Rozman said...

Hi Mr. Pall,

Why did you put the prunus mahaleb in the green house?


Houston said...

Hi Walter,
Does this greenhouse have a controlled temperature? If not, I am interested to see that your trees have no mulch covering the pot, and some are elevated above the ground.

Here in Chicago, USA, we are taught to winter our bonsai on the ground and cover the pots with mulch. This is intended to insulate the roots from repeated freezing and thawing, and to keep the pot at ground temperature rather than air temperature. Do you find that to be unnecessary?

Walter Pall said...

Nik, because I have wired ane bent the ends of this years new growth in October. If one does this the tree absolutely needs some winter protection. Otherwise Prunus mahaleb are quite hardy.

Houston, this greenhsouse has almost no controlled temperature. Only when it gets down to minus 10 Celsius which is around 10 to 15 Farenheit I start a small heater with 2,000 Watt. This is sufficient. Around 800 trees are right outside on the gound under the snow without further protection

Nik Rozman said...

Wel that explains it.

Dallas from Utah said...

Hi Mr. Pall,
How do you keep your trees from coming out of dormancy in the greenhouse? I have a greenhouse for my tropical bonsai and it will easily get to 80-90 degrees F during the day. Any deciduous I would put in there would start to leaf out quickly. Thanks for taking the time to answer these questions.

Walter Pall said...

Dallas, I assume your greenhouse is probably way too small and does not have automatic window opening devices. It is importat for the hosue to be as large as possibel, to have window openers which react quickly when the sun heats the house up, and to provide shade if the sun is too strong. My trees start with swelling of buds by middle to end of March, which is four weeeks earlieer than outside. By beginnign of April I start bringing them outside gradually.
I leave the doors open as long and as often as I can. It gets quite cold in there, way below freezing for many weeks.

Daniel Dolan said...

Dear Mr. Pall:

Thank you for the beautiful winter photos. And for the presentation of pots by Mateusz Grobelny whom I have since corresponded with about shipping some pots to Chicago.

One short question about the photos inside your greenhouse. The soil appears to be somewhat dry. My few fatalities have been a result of overwatering in winter for fear of roots drying out for trees in a protected workshop environment.

I strive for "damp" but not "wet"....but is there a benefit to letting them dry out a little more between watering?


Dan Dolan / Chicago / Midwest Bonsai Society

Walter Pall said...

when it is below freezing I don't water at all. Thus the soil appears dry. It is frozen stiff though.
When there are a few days with warmer temperatures I water everything throughly.
One has to get used to the fact that you can NOT judge watering from the dry appearance of top soil with modern substrates. They appear to be too dry most of the time while they are not.