RAISED BEDS

[August44]

I actually got the idea of using the raised beds by watching some larger SA Fir trees this summer that I have collected. Some were just put on top of the soil in their pots in old wine barrels that we usually use for flowers. Some in Anderson Flats, some in regular pots. Other SA Firs were just in their pots on the bench. The difference was absolutely amazing! The ones on top of the soil in the old wine barrels went crazy with a lot of new, dark green, healthy growth top to bottom. The ones on the benches, not near as nice. I went to pick up one of the Anderson Flats from a wine barrel one day and I couldn't move it. Roots have gone through the bottom of the flats and into the soil. Just amazed me what that does for a tree. Maybe I just need to set the pots on top of the soil verses planting the trees in the raised beds.

What do you think about using Perlite and a good grade of potting soil or top soil for the beds. Way cheaper than pumice that I have to travel many miles to pick up. I understand about perlite floating and/or blowing a bit.

I just want to say thanks to ALL of you who participate with ideas and all the help you provide with questions from me and everybody else on this forum. All of you deserve metals, but I can't afford them. Thank you!

 

[JeffS73]

Maiden and Shibui are right about the problems I encountered - not thinking about the hydrology. I was also trying to provide frost protection. My pots are now sat on top of the soil in the raised beds, so I can report back after Winter

 

[Shibui]

What do you think about using Perlite and a good grade of potting soil or top soil for the beds. Way cheaper than pumice that I have to travel many miles to pick up. I understand about perlite floating and/or blowing a bit.

Usually just good quality topsoil will be fine for a raised bed. The increased drainage of a raised bed should not stay too wet. Potting soil will probably be more expensive and will drain even faster but may be easier to remove from the roots at transplant.

The difference was absolutely amazing! The ones on top of the soil in the old wine barrels went crazy with a lot of new, dark green, healthy growth top to bottom. The ones on the benches, not near as nice. I went to pick up one of the Anderson Flats from a wine barrel one day and I couldn't move it. Roots have gone through the bottom of the flats and into the soil. Just amazed me what that does for a tree.

Many others have similar experiences and some even use escape roots as a technique for fast tracking bonsai growth.
Even though we think we are supplying all the tree's needs in a pot on a bench that's not often the case. Fluctuations in temp, soil moisture, etc, etc as well as restricted root area. Escape roots definitely mean much more growth and health. Down side is sometimes one root gets ahead of the others and we end up with lopsided nebari so I still like to check every year or 2 to head off problems before they get out of hand.

Trees can be planted in soil or in pots on top of soil raised bed or flat ground. All are legitimate techniques and will work.

 

[Maiden69]

Maybe I need to clarify something with what I meant by "drainage layer". A drainage layer to me is 5/16"-1/2" pumice and most of the above substrate is pumice also but 3/16"-1/4", so I'm using the same substrate just different sizes. Maybe some of you were thinking I was using a different substrate all together for drainage. Not sure that the larger size for drainage is a good idea. I do understand now that the substrate needs to be the same top to bottom, so maybe I need to stop the large substrate for drainage thing.

You don't need a drainage layer for a pot, much less for an above ground bed. Use the same size substrate in the entire bed. Using a drainage layer of lava/pumice topped with "X" material is just asking for trouble.