I've got several Smart Pots as well as testing out a line of Fanntum Containers for my containerized fruit trees. I live in Central CA where the heat is crazy. However, only two of them have the gritty mix and I was betting I wouldn't make it through the summer in those. I suspect the gritty or 511 mix in a fabric container, in dry 100+ weather, will not work unless you are a watering maniac. I made it through last year in plastic containers with the gritty mix (added 20% more turface and reduced granite) but the hottest days did require container shading. Also the smallest containers, and one citrus tree where the roots were extensive and filled the container, required a cache pot or placing mulch around them. Those is my area scoff and say you *must* use peat or coir in every mix to survive the summer heat. Well I've certainly found that peat "bakes" (as does other media), when used in plastic containers in full sun. Just because a mix holds lots of water doesn't mean you can ignore root temps. There is not enough aeration in a heavy water-retentive soil in a plastic container for it to release the heat. A benefit of fabric containers is when you place them directly on the ground, the capillary wicking action of water in ground contact is supposed to help drainage even when you use poorly draining soil/media. In addition, supposedly the fabric containers "reduce soil temps" due to the aeration. So this year I'm testing with a typical peat-based soil, and an even heavier mix of cheap potting soil, in Smart pots and Fanntum containers on the ground to see how well they do. I'm hoping they'll require the same amount of watering as the gritty mix in plastic, yet be cooler. Don't know yet. I'm also testing blueberries in the plastic grow bags which are white on the outside and black inside. They are so cheap (like .75 ea for 10gal) and I want it to retain moisture and have cooler roots for the BB. BTW, so far I really like the Fanntum containers. Though they won't need "washing" like Smart pots, I do not know how well the "tarp like" material will last from UV damage. But the wire support around the fabric container is *very* helpful for larger sizes 10gal and up. I wish their 5gal sizes included wire supports, but they don't. It's not a retail type place, no online ordering, etc and they mostly cater to growers who purchase in bulk. But Alan Fanntum is sharp, flexible, and pleasurable to work with. He did the best he could to fit the containers in a small package to ship via UPS. You may pay as much for shipping as the containers themselves, but overall they were still much cheaper for me than Smart Pots. A 10gal container runs $4 whereas the smart pot was about $10 locally. Smart pots become economical if you brave the largest sizes, as they are only a few bucks more than the small/medium sizes.

I have used smart pots for tomatoes, cucumbers and several other vegetables for four years and love them. I haven't had problems with blossom end rot or other things like you describe. I suspect your problems are more likely caused by other things, primarily the variety you are growing or the potting mix. Search BER on GardenWeb and you will find that some varieties, like many paste tomatoes, are most susceptible. Uneven watering that affects cacium uptake is another cause. As for cucumbers, I finally overcame many problems when I started growing Diva, a variety that is resistant to cucumber beetles and the many diseases they spread. The next most likely cause of your problems is the soil mix. For the first three years I used smart pots, I used a mix of 70% soilless professional mix (Promix, Metromix or Fafard) and 30% compost. I only used organic fertilizers. My results were mostly good, but my plants suffered when we had a lot of rain in the early weeks because the soil held too much moisture when the roots didn't fill the pots. This year, I discovered Al's 5-1-1 mix and filled all my smart pots with a modified version of that. Since they sit directly on the ground, Al told me they are more like miniraised beds than traditional containers. My mix is five parts pine bark fines, and one part each of peat, compost and Turface. I also added one tablespoon per gallon of agricultural lime (which helps with preventing BER) and one tablespoon per gallon of Osmocote Plus with trace elements. (Al also convinced me that organic fertilizers don't work as well in containers as they do in soil.) This mix held up very well to lots of rain in June and recordbreaking heat in July. Its also significantly cheaper than bagged soil. My tomatoes and cucumbers have done very well in spite of the usual insects and diseases. The final source of problems is those insects and diseases. I have been much more aggressive in responding to problems this year than in the past, and it shows. I do stick to organic pesticides, like neem and spinosad. I've had the best gardening ever thanks to Al and all the other great folks who share their experiences on Gardenweb.

Thanks Phebe. I originally was going to go with an all dry Japanese inspired garden, but then the fruit & veggie bug bit me, so I am trying to find a balance between stuff and negative space. I suspect that balance will always be shifting... Al, I'll keep my eyes on the roots as I progress down this Smart Pot adventure. Six new Dave WIlson low-chill fruit trees: Royal Lee Cherry, Minnie Royal Cherry, Red Barron Peach, Saturn Peach, Mid-Pride Peach, Arctic Star White Nectarine. Potted up into Smart Pots filled with UniGrow potting soil, left the root ball intact and just nestled it in the middle with the potting soil packed around it. I'll be doing more research and getting some root training, so in the Spring I can repot and prune, possibly using Al's Gritty Mix. Here is a link that might be useful: Front yard with 6 new containered fruit trees

Is this a valid concern? Enough to either switch to standard pots instead, or increase the ratio of calcined products even further? I'd say it's a valid concern, given the evaporative surface is probably in the neighborhood of trebled. I can't tell you what to do because it sort of depends on how much you're willing to water. I suppose it you're willing to water daily if that's necessary, a try at upping the water retention with the added water-retaining products is a good bet. Regardless of what you try- why not also try at least one variant container type with a regular mix (if you use 1 pot) or a super soaker mix if you use the fabric bags. - And just out of curiosity, if the unscreened Turface/DE doesn't affect aeration why do you (seemingly) prefer perlite? Cost- or weight-related? I use perlite because I don't want or need the additional water retention afforded by products like Turface or calcined DE. I don't particularly like to water, but my plants appreciate me making soils that require frequent watering. I have at least 200 containers, so I have to make the watering rounds daily (unless it rains) anyway, because I have so many bonsai pots that have 1/2 cup of soil or less. Some plants only need watering every 5 days or so (like pines & junipers), but the little guys demand close attention. That's not the soil's fault - it's related almost entirely to my choices that limit soil volume. Should I water based on the volume of the media with 5-1-1, or should I water based on the size of the plant? Both of those considerations are part of what you use to decide when to water. A well made 5:1:1 is quite forgiving when it comes to the potential for over-watering, so common sense usually carries the day. After a planting is established, you might wait for a weekend when you know you can watch a plant carefully. Water on Wednesday or Thursday, then watch carefully for the first sign of wilt to give you a better idea of where the limits are. It won't take long before you'll be factoring light levels, wind, humidity ..... as a matter of course into your determination of when to water - it'll become almost reflexive. I hardly even think about what I'm doing as I water - usually thinking about something else. If you're in doubt about whether or not the plant will be ok until your next opportunity to water ..... you can usually water w/o ill effects because of the nature of the soil you're using. - Would you recommend the seedlings in an intermediate pot before they go into their final 15gal homes? Personally, I wouldn't bother, but I WOULD be mindful of making sure I keep the soil moist where I think the roots are. IOW, if all the roots are in the top 3" of soil, you better water so the top 3" is moist enough to satisfy water demands. As noted, if you run into this issue at transplant time, you can set the fabric bags on the ground (to take advantage of the earth's wicking action, or set things up so an actual wick is keeping the lower part of the container from staying soggy - say if you have to water daily immediately after transplanting. Don't worry about asking questions. That's what drives the forums. If I can't answer, there are a lot of smart folk here who can help. Once I'm a part of as thread I usually follow it until it fades away, so if you're getting replies from others (say on this thread) and I seem to have gone missing, it's just that I agree with what's being said & there's no need for me to add anything to 'their' able advice. If I think you're not getting good info, I usually offer some sort of input that will make whoever's following the thread view what was said in a light that shows it might not hold up to more than casual scrutiny. With the number of messages I get from people who actually make a point of saying they are totally confused by conflicting information, it's probably as GOOD thing for everyone if we make it more of a point to hold each other's feet to the fire so people can rely on what's being presented as good advice. That's my story and I'm stickin' to it. Thanks for the kind words, BTW. Al