Hey All,
I posted this in Trees & Shrubs and was advised to post here also. Here goes:
I have one on order and I'm considering using it in a container - at least for a while. What is the minimum size container I should use so I can leave it outside all winter? I am zone 6b - 7 according to the new map but I prefer being conservative. Further, is there a minimum size container that would allow me to leave it wherever it is and not bring it to a more sheltered location? If that's possible, I would then fill in with annuals until the tree grows sufficiently. Thanks.
Regards,
Victor
Chinese Fringe Tree in Container?
How big is the plant material you're working with? The size of the container has little to do with hardiness except to the degree that containers with a large bottom area in contact with the soil will show slightly greater geo-thermal moderation of ambient air temperatures than containers with a small bottom surface. Appropriate container size is determined by a multi-faceted relationship between A) the type of plant material B) The size of plant material C) Cultural conditions, such as temp, wind, amount of sun, rainfall, etc D) and most importantly, the soil porosity. No one can answer your question with any degree of reliability unless something is known about A-D.
Burying the container against a building (preferably on the north or east side, out of wind, will offer you the same (or a better) degree of hardiness than plants that are planted out in the landscape.
Al
Thanks Al . A) has been answered already. B) is described as 2-3 feet at shipping. C) Will be in full sun. Can't predict rain, temp or wind. Wish I could. D) Most likely a good quality potting soil.
Please correct me in the following. If I took a plant whose 'true size', if you want to call it that, is say a two gallon pot, and a) left it in the two gallon pot, b) planted it in a five gallon pot or c) planted it in a half whiskey barrel, I would think the following to be true. All else being equal, the largest container would provide the best winter protection because 1) there would be LOTS more soil between the roots and the outside world, thus protecting it (insulating it) from the cold and 2) chances are the thickness of the largest container is substanially greater than that of the smaller ones, thereby adding to the insulation. Of course the larger sizes will also take longer to dry out. What's wrong with that reasoning?
I know burying it would be better and planting it would be better still. Thanks again.
By "size" of plant material, I meant some feeling for the mass. Length of the material and the existing container size is inconsequential, as a 2-3 foot plant can arrive anywhere from nearly rootless to something with a 30 lb rootball (unlikely, but possible), with a dozen small buds to hundreds of open leaves & viable buds straining to open. What you would be determining here is how fast you might expect the plant to use available soil moisture - a very important consideration when determining appropriate container size, and that is most easily estimated if you have an idea of the bio-mass of the plant.
"A good potting soil" leaves lots of room for interpretation based on our individual experiences. For example, I think that my idea of a good potting soil likely varies considerably from what you might consider a good soil. The key is this: If you want to retain plant vigor and promote maximum plant vitality, when you grow a small plant in a large pot, it should be in a very fast soil; that being a soil with at least 80% total porosity and a minimum air porosity of 40% when your soil is at container capacity (this is the saturation level of the soil after it is fully wetted and has just stopped draining freely). You won't find a soil like this in a bag.
More mass does not necessarily protect the plant from actual low temperatures. Technically, it is not the duration of exposure to cold, only the actual low temperatures that roots (and other viable tissues) are subjected to that determines whether or not cells rupture and tissue dies. What's wrong with your reasoning in 1) is: In order for insulation to be of any value, there has to be a source of heat the insulation is conserving. An imaginary illustration of this principle would be seen if, before retiring, you were to take an 8 oz Styrofoam cup filled with water and a steel can of water (same volume) and place them side by side in a freezer. The water in the can would freeze much more quickly than the water in the cup, but by morning, the ice in each would both be the same temperature, which would be very close to the ambient air temperature of the freezer. Add a small heat source to both, and the better-insulated container is far less likely to freeze than the uninsulated one. Can you see how the added insulation depends on an extraneous heat source and only moderates the rate of temperature fall & not the actual low temperature? Of course, the added insulation, though not very efficient, would help to trap and conserve a small amount of geo-thermal heat from the soil, it would be largely insignificant and would certainly not make a "zone's worth" of difference - probably not even a half-zone.
If you're determined to grow a small plant in a large container, why not use the large container as a cache pot? This will allow the plant material to remain in a more suitably sized container and greatly reduce the rot-risks that over-potting brings? As the planting matures, you can increase the size of the container it's in until your pot/soil combination is appropriate for the plant material.
Al
Thanks for taking the time to answer in detail, Al.
Victor
when planting a small plant in a large container (in the hopes of the small one eventually filling it out), i like to plant thirsty annuals on the perimeter. these little plants will take up some of the excess moisture associated with potential rot, if that makes any sense at all! of course, that would be a moot point during cold months as the annuals would die in the cold.
I've been looking at rose standards and all the questions and answers by Victor, Al and Debi are exactly what I wanted to know. Thanks to all three.
One more question Al: Can you explain "fast" soil to me? Would that be fast draining?
Thank you for your time and your help.
arlene, i think it means "fast and loose". lol
You're too much! I thought the rose would enjoy our compost so I'm wondering how much compost to how much potting soil (would Miracle Gro potting soil be acceptable?) and how much perlite. For every two quarts of compost what would the other amounts be?
pirl, wrap your head around this very wonderful thread. http://davesgarden.com/forums/t/527353/
Yes, Pirl - a "fast" (and loose) ;o) soil will be very free-draining and hold lots of air, even when fully saturated. Because we cannot see what goes on below the surface of our soils and we cannot see air, we tend to forget about it. If you were building a soil to encourage best plant vitality, your goal would be to keep a steady supply of moisture available to roots while encouraging large amounts of air throughout the soil; then, amend the probable best choice to comply with how often you are willing to water.
Al
Thanks, Al. What is the reasoning behind tamping down the soil when we plant directly into the garden? Wouldn't those plants want the air just as much as potted plants?
What about tamping down when planting? Should that be kept to a minimum just to stabilize the plant? You'll still see 'experts' talk about tamping down while planting 'to get the air pockets out'!
Victor
Oops - Pirl beat me to it!
This message was edited Jan 28, 2007 2:36 PM
Thanks, Victor - now I don't feel so lonely.
Yes - tamping should be done primarily to secure rootage and help prevent the plant from toppling from the pot or being moved by air currents, which can break newly formed hair-roots and slow establishment. There is also some benefit from full contact of soil to roots in that it facilitates water assimilation at a time when maintaining the plant's turgidity could be problematic. The pockets themselves would only present a problem if the soil was allowed to dry to the point where inter-cellular water in roots began to migrate across cell membranes into the dry air pockets. Full of water vapor, they would cause no physiological problems.
Al
Al - you're better than butter!