Permeable means it s ability to allow liquids to pass through. Chicken wire is fine if you have moles/voles but landscape fabric is only mildly permeable. Testing consistently shows it slows drainage substantially. It is not ever recommended for the bottom of a bed by experienced gardeners and it would have no effect on the moles and voles anyway. 75:25 compost:loam is high on the compost side and the quality depends on your definition of "loam". Means many different things. But as long as it isn't so-called "top soil" or sand a 50/50 mixture of it would probably work. More commonly you see the recommendation for 40:60. But you will have to add more compost at least once a year and better 2x a year as it continues to shrink as it decomposes. I get the impression you aren't interested in first trying to improve your native soil and incorporate it into the bed, correct? That is the best route to go. But if not then you need to understand that overtime it can affect whatever you fill your bed with unless you made some sort of solid bottom box which is not at all recommended. But you can still make it work with a framed raised bed on top of it with chicken wire or hardware cloth on the bottom IF you keep the bed well and frequently amended with quality compost. Over time the leachate and soil bacteria will improve the soil below the bed as well. Dave

I planted a Don Gillogly sapling about 6, maybe 7 years ago. I drove 400 miles to get it at an Orange County nursery, and bought another for a friend. Hers died, but mine lived and since we live only two blocks apart, I can't say why I had better success- I would guess because I practice benign neglect and don't water very often :) The tree was about 5 feet tall when I moved 4 years ago and I returned to my house in Cupertino, CA in March of this year to find my avocado tree had grown considerably and had fruit. The tree is about 12 feet high, so it is either going to stay relatively short or it's going to grow very slowly. The fruit is absolutely wonderful- no strings, a true avocado flavor, not watery flesh, buttery and rich and about 7 inches long. A weird thing about the fruit- they have a channel, like a skinny conical envelope from the seed to the stem. The tree now has a second crop for this year. My tree has spread horizontally (maybe 10 feet from left to right) so it seems like a tall bush in some ways. It is near my house and may get a little protection from cold and wind because of that, but our winters get into the low 30s at night and the tree has done well without any special care or fertilization. When I came back this year, I did throw some avocado fertilizer on the ground under the tree. I'm very happy I planted it.

I for one agree with you for the most part. There are a lot of us growing rare fruits in containers...even some of our more climatically advantaged members grow some in containers. C'mon...say it again...."climatically advantaged". Y'all like that don't you? This is of course, quite the opposite of my climatically challenged area of Ohio. But I digress. Due to my climate...I have no choice but to keep most of my plants container-bound. My plan all along has been to practice agressive pruning to keep the plants smaller and more manageable. The experience I've had with my apple trees is that the more I prune, the more apples I get the next season. Is there a downside to this somewhere? I believe there is. Even if pruned well, these trees are going to reach some size. There's root restriction and then there's just a root mass where there is very little soil left in the container! We've all experienced that. You grab the plant by the trunk, pull, and the entire plant comes out of the container. Where the hell is all the soil? I can't see any benefit to the plant when it reaches this point. No way to retain moisture and other goodies that soil provides. Okay, time to root prune and replant. This is fine and dandy and I do this all the time...when the plants are manageable. This is not going to be the case when these plants reach a certain size/weight. This has been a huge concern of mine for some time. And I'm certainly open to any suggestions this group may have. So while these plants that are grown in hard clay and other restrictive soils, they are still getting more benifits from that little bit of soil than I can probably provide my plants in containers if I let the roots take over the container. Maybe this is where the dissention stems from? Could I do a Bill Whitman in my greenhouse? Meaning, could I remove all of my solid clay, high PH soil and replace with the stuff our plants love? Sure, but it would kill me physically and financially!

Woo hoo! A much needed forum! I love it! Thanks for the heads up! Now I wish there was a Macadamia Growers and Olive Growers forum.