Rich:

Why not just put the pots above ground?

I agree with fruitnut. Just keep the pots above ground. Not sure why you would want to bury the pots?? Here in S. Calif., in order to successfully be able to grow blueberries (without a gigantic hassle), we grow them in containers so we can control the pH. Just put them in attractive pots, or 1/2 whisky barrels, and you'll be able to grow them very well. And, they are very attractive plants, too, so a double benefit :-)

Patty S.

Put the pots about a third into the ground and some drainage holes a third up. Insulate the pots above and you'll get all the advantages of having some of the pots in soil.

If the sun hits the pots all roots near the southern side will be killed if you don't insulate.

If you bury your containers in soil that does not drain, neither will your containers, no matter what the mix is in the container. Raise your containers so the drain hole is clear of the ground if you wish to control the moisture content of the container. If your container is in full sun it will have to be shaded or the temperature in the root zone is likely to kill the plant. Al

I've had blueberries and many other fruit trees outdoors all summer in 15 gal black pots with no problems. Perhaps it's because we are at 30 degrees so sun is nearly straight overheat at mid summer. Shading the pot surely can't hurt but I'd be more concerned of heat or cold in a small pot than in a 24 inch pot.

Has anyone actually suffered either heat or cold damage in pots?

You may not see the problem but if you remove the plants from the pot I believe you'll see that roots are not growing on southern side of pot so you are wasting some valuable space. I admit this is a little piece of info I got from Carl Whitcomb's book "E.and M. of Landscape Plants" so it's not actually based on my experience.

Also, putting a third of the container in the ground may make the lowest part of the pot soggy at times but this may be a benefit. A pot has been designed to leave the very bottom undrained and having near constant water on a small percentage of the pot seems to be quite beneficial. Roots will find enough aerated soil If you put some drainage holes above the soil, but water will be more constant.

If your soil is clay what is the value of digging the pot in . I dig my pots in because I have great farm soil which is amended with perlite , peat moss and Humus. As you see this is not my normal soil but it is the soil in the raised beds. Every year I build two raised beds now I have 8 raised beds for all my Vegetables and trees in pots. I did that after too many failures with my original soil.

Blueberries actually don't seem to benefit much from having pots set in soil (the roots stay in the pots for a long time) but most trees do much better with some access to real soil in my experience with hundreds of potted trees in my nursery. Soil is better than potting soil, all in all.

Thanks for all the input. I have several reasons to want to bury the pots: mainly to block out the voles eating the roots, but also to decrease root competition from nearby trees. Not to mention which, I bought el-cheapo pots on sale at Home Depot, and I doubt my neighbors want to look at them for the next few years.

I have amended the soil in a raised bed so there is about 10" of decent soil and composted peat above the clay, and I think that part drains pretty well. One big problem is that the 24" pots are a lot deeper than the soil.

It sounds like my options are to try some buried pots with additional drain holes placed above the water table, just leave the pots out of the ground, or to scrap them. Maybe I'll experiment with different ideas and report back in a year or two.
Rich in Richmond

You want to leave the pot in the ground to provide insulation and keep the pot cool during hot days. You want to leave it above ground to help drainage. So as a compromise, since the days are getting warm but not hot yet, why not leave them above ground? Then when it's hotter and drier, put it in ground with some gravel beneath to hold the occasional rain water.

Another alternative is to leave it above ground, but put a mound around your pot. That should prvoide both insulation and drainage.

I guess I should clarify: I have an existing bed which is 4x40 feet, with old blueberry plants, and several large gaps where I had to take out dead ones. Having read about blueberries on this forum, and thinking that they needed a big pot, I bought some cheap 24" pots at HD, but they were on clearance for a reason: they fell apart when I tried to pick them up after I got home. So, I was concerned that they would not be able to stay together while holding a full load of soil, plant, and water. I know, I know--don't dig a $30 hole and put in a crummy $14 pot. Since they are normal proportion for flower pots, they are very tall and conspicuous. I don't mind if my neighbors think I'm eccentric, but I don't want them to dislike me. So, my reasons for wanting to set the pots in the soil are mainly aesthetic, but also practical.

So, yesterday I returned most of the big pots, and bought a short wide fiberglass pot. I planted the giant pot in the spot with the best drainage, drilled extra drainage holes in the side, and stuffed them with hardware cloth. I put the fiberglass pot in the next best site with lots of drain holes, and in the wettest spot, I lined the hole with hardware cloth and no pot. I filled them with pine bark, peat, sulfur acidifier, and perlite, with a little topsoil tossed on top. Now, I'm just waitiing for the plants to come in the mail!
Whew!