Early July is pretty much the cut-off point on planting any tomato seedlings. Even still, you'd want to plant a variety that will be able to produce ripened fruit by mid September. I had rooted a sucker from the Black Krim, potted it, and then watched it start growing rather aggressively. Since the mature Black Krim plant had a long stretch of being unproductive, I figured why not "even out" things by trying to grow the sucker into a full fledged plant. It would also give me a chance to try out a few things I'd learned.
I ended up buying another SWC from Home Depot. But this time I took it apart to see how the reservoir and connection to the main container was designed.
As you can see, there's not a lot of drainage from the container to the reservoir. You see those slits in the 4 legs? In my potted containers there are roots running through those that sought out the water. While I appreciate how the design helps hold back the soil from the water, it doesn't provide much in the way of a wick action from the reservoir into the soil. This probably contributed to the Black Krim growing so slowly. I decided to make a modification akin to a typical design for DIY 5 gallon containers.
I saved this small plastic container from a soup I'd enjoyed from Trader Joe's, which is pretty much the right size for a central wick basket on this pot. I got out my Dremel, put on protective goggles, and got going.
I cut a hole in the floor of the container. It's a little crude but sufficient for the project.
The plastic container had a prominent lip to it with a step that nicely overlapped the diameter of the hole I'd cut out. So I trimmed off the lip to make the basket fit through the hole but not fall out.
I cut a bunch of slits down the sides and then drilled holes along the bottom. The plastic is sturdy enough not to buckle with all of the cutting I did. The slits will provide ample irrigation, while the holes will allow for the last 1/4" of moisture to be drawn up by the roots if needed.
The basket fit just right in the hole and when I attached the reservoir, it rested flush with the bottom. I didn't photograph the rest of what I'd done, so I'll describe it briefly. I cut up 3 strips of microfiber cloth, about the length of the whole container. I then laid the strips into the wick basket evenly spaced in a tri-spoke layout (like a Mercedes symbol). Next, I poured in the potting mix. I also mixed in fertilizer and other natural ingredients (like eggshell powder) and kept the microfiber strips at even lengths upward. Once the whole pot was filled, the microfiber strips ended just under the surface. I did this based on a tip I'd read about using microfiber cloth as a wick device, which provides great capillary action while also being impervious to rotting (unlike cotton based materials).
Here it is planted in the modified SWC, after the mulch layer was applied. This photo was taken 4 days ago and already it has grown about 2". The roots are about 8" away from reaching the bottom, so I expect once that happens the growth rate will really take off. It'll be very interesting to see the difference. Of course, the plant is also benefiting from warmer weather at this point in the season (versus mid May), but if the grow rate is seriously faster then I'll know this modification was a worthwhile improvement.
UPDATE, one month later (August 21st 2013):
This plant really took off like a rocket, as you can see here:
Very healthy growth with large, lush leaves and plenty of fruits that have set. Some of the lower branches curled a bit, but that was caused by the long heat wave we had last month. I've already chopped off a few and may dispense with the few that remain once the plant grows a little taller.
When I popped off the reservoir to clean it, I noticed the basket was not deforming or buckling in any way, so all of the drilling apparently didn't weaken it. There also wasn't any roots penetrating it, but I do think that next year I may put in swatch of lawn cloth to help discourage the roots from trying to get through.
All in all, I have a feeling this SWC modification worked out well, but the real test will be when tasting the ripened fruit. If they don't suffer from a watery or lesser taste than the others, I'll consider it a complete success and will modify the other containers next year.