Hi EG, thanks for weighing in. I remembered reading your posts when Raybo first tried reducing the orifice/basket size on the ETs. I've gone back over the thread, and scanned through most of your blog looking for clues on your trials but didn't find much info (sorry to be so nosy). You mentioned someplace that you believe the key to managing the moisture level has to do with the surface area of the soil to water in the transfer zone (I'm paraphrasing). Could you possibly explain that? At first I though you meant the surface area of the orifice, but then the surface area of the wicking basket in contact with the water reservoir. I don't know if you mean the total area, or just the open spaces (holes or slots in the wicking basket), or are you talking about the total surface area of the potting medium in contact with the water reservoir? When you talk about surface area, do mean the all the little voids within the potting medium that get filled with air or water? Do you think the wicking chamber sizes and/or orifices in my proposed experiment are too large? I have noticed that some DIY SWC instruction use plain slits in the wicking chamber instead of holes. Would that make a difference, and if so, should I make certain that all my experimental wicking chambers use the same number of holes (normally I'd put more holes in a 2" diameter wicking basket than a 1"). Another experiment could focus on the amount/size of openings. I think there's probably several different possible ways to manage moisture in SWCs. It'd be great if we could narrow down what works and what doesn't. You can never have too many tools in your toolbox. I'm also thinking of picking up an EarthBox and a a Growbox and getting measurements off of them to compare. I never would have thought that too much wicked water would be an issue with these. Last year I was so worried that my early boxes wouldn't have enough! I'm also wondering that once I manage to reduce the moisture content optimally for tomatoes, would that same setup be detrimental to the plants that did well in the wet conditions (curcubits, peppers), or were those plants just better able to adapt? So many questions. Where are the Mythbusters when you need them?

I always suspect too much water when SWCs are involved. I see some black on your tomato stem that looks like a disease, but I've seen the same thing on plants that drowned. I've found one of the best ways to determine moisture level in a dual bucket SWC is to lift up the upper bucket and feel the weight. It's somewhat subjective, but if it feels heavy for its' size, then it's likely too wet. If it feels unexpectedly light, it's too dry (and in the middle is just about right). A 5 gallon bucket is very deep, so you can't judge the total moisture level by just the top 4 inches of mix. Did you recently have a heavy rain/s? If so, your mulch cover may have actually funneled too much water into the crown of the plant, the smaller plants would be more susceptible. Are your drain holes low enough? HomeDepot buckets vary in design depending upon region, so if you used the GB measurements you need to double check and make certain that the drain hole is at least 1/2 inch below the bottom of the soil bucket. Make sure that buckets are relatively level and if not, rotate the drain hole down hill. Lift out the soil bucket and look at your wicking cups. Make certain that they didn't get crushed or split, allowing too much water in. What size cups did you use? The cucumbers may not do as well in Raybo's 3:2:1 mix as tomatoes and peppers. I have a Zucchini that's doing gangbusters in straight Sta-Green potting mix, and another that's not doing that well in the same mix my tomatoes love (3 parts Dr. Earth potting soil, 2 parts Fafard Aged Pine Bark, 1 Part Pearlite). My point is that it's possible that there are different things wrong with the cucumber vs. the tomatoes/peppers. You can't rule out water problems just because one pepper plant died and one survived in the same container. One plant could have received too much water at the crown (mulch cover funnel), the other could have been large enough to withstand deluge, or could have been better adapted to the wet conditions. What brand potting mix and pine bark did you use?

I used a ratio of 7:2:2 of fines:peat:perlite. The original mix recommended in the earlier post was 7:2:1:1 of fines:peat:perlite:vermiculite but I didn't have any vermiculite. I figured out the right ratio of lime and Osmocote 14-14-14 based on some other postings but foolishly didn't note it down (maybe it was 1c of Osmocote for 20 gallons of fines). I've also supplemented twice with MG 24-8-16 by simply adding a teaspoon directly into the watering hole. I did this in mid-May when growth actually kicked in and again when I started getting flowers about 3wks ago and the weather got hot. In the second watering I also directly fertilized the cucs with an additional 1gal of MG I had in a watering bucket left over from other fertilizing chores. I have 9 more tomato plants growing in Mel's Mix in raised beds that are roughly comparable developmentally to what I have in the SWC, despite the fact that the SWC get somewhat less late afternoon sunshine as they are close to a inner corner on the patio. I know cucumbers have a reputation for fast growth but I have to say that after the second fertilization and some summertime heat they seemed to explode from 6" to 4' in about two weeks while generating huge numbers of blooms. I have very high hopes that the SWC can provide optimum conditions for a very thirsty plant. Looking back at the original posting I see that there were some concerns about whether the adjusted soil mix would wick enough for seedlings w/o deeper root systems. The cukes, pepper and toms were all planted as seedlings although the cukes were less than a week old (given their reputation for not enjoying transplanting) and seemed fine - the under-planted nasturtiums were planted as seeds and had no problems germinating (100% germination, I think). The lettuces were direct seeded and I did need to top water them - this was easy because their pot was shallow and uncovered. I know there are a lot of designs out there for SWC but I'm very happy so far with the nested buckets - using the top as a plastic mulch has been VERY effective and I've only had to fill the ~1gal reservoir a handful of times since mid-May. I imagine as the tomatoes grow they will respire more water and refilling will become an issue but so far they have been nearly zero maintenance. The nested buckets were also nice since they took about 10 minutes each to make and were easy to put the cages into - next time I'll clip the cage wires and wire tie the lowest rung of the cage to the bucket top itself, but so far so good on stability (obviously this only works for bush or determinant tomatoes). By comparison, the petunia in the hanging SWC needs daily filling of the reservoir. Weirdly, I have the exact same container with a miniature trailing rose sitting on a low wall and it's actually over-moist and I never top it up, just relying on rainfall. I don't know if this is a result of the extra exposure to wind and sun that the hanging container gets or whether the petunia itself is using the water.

Thanks EG! It doesn't seem like a lot, but I figured why not try a little of the plants I REALLY like :-) As I said, the drip irrigation system worked really well and when I expand the garden next year, I plan on expanding that also. Although not as 'elegant' as the EB AWS or Raybo's, the water timer helps with the overflow since it only allows water to enter for about 15 mins 2 times per day. I thought about the nutrient leaching and so I did exactly what you suggested by placing the drip hose directly into the fill tube. The fertilizing...especially over the long-term, was problematic for me mostly because I really didn't think it through enough. The mix I add to the soil at the beginning of the season got the plants off to a great, sturdy start, but about half way through it, I knew I was in trouble. I'm thinking about burying a small, covered container at the same time I plant the veggies. Then about half way into the season, I'll push aside the large bulk mulch, remove the cover (which will be at ground level), place in a mixture of potting mix and another batch of fertilizer and then see what happens. I'm not sure it will work, but I much prefer adding the fertilizer to the soil rather than top-down watering. And since minerals are heavier than water, I don't think that a completely soluble fertilizer will give the plants all the extra nutrients they need as they head into their fruit production. The 'natural' fertilizer formula included in Ed Smith's book was a CRF so that may be all I need (in addition to the extra lime.) What do you think? Donna H.