SIP Improvement

Watermelon SIPs on the Chicago rooftop of the Green Roof Growers

We’ve featured self-irrigating pots (SIPs) in our first book and have done a lot of experiments with them over the years. One of the problems with growing tomatoes in SIPs is that the roots can get into the water chamber and cause problems and diseases. I found a nice workaround to this problem via an anonymous tip on a BoingBoing tomato post:

With tomatoes, you need to lay down a layer of high-quality landscape cloth (don’t use the cheap stuff) to keep the tomato’s roots from getting into the water chamber. You run it from the bottom of the bucket all the way up to the top of the soil line. If those roots get to the water chamber, your tomatoes will end up tasteless and watery. As long as you lay down the cloth and keep the SWC full, use good potting soil, fertilizer, etc. – you will have some damn good tomatoes, and plenty of them!

I’d also recommend growing smaller tomato varieties in SIPs.

If you’re using SIPs this season, leave a comment and let us know how it went.

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  1. A lot of the things we’re doing in our garden this year are experimental. While most of our tomato plants were in tried-and-true soil, I did put one in a SIP just to see how it worked. While it was the first plant in the garden to produce fruit, it never produced much, and the fruits were tiny, Roma-shaped but about a quarter the size of a typical Roma from the other plants. They were cute, just not significant contributors to this year’s canning extravaganza. It’s an heirloom, but I can’t remember the name. Not supposed to be so small. In any case, things are still producing out there, so I haven’t taken the opportunity to check the root system, etc, to try to diagnose the cause.

    We had much better luck with our peppers in SIPs, which seemed to take a cue from the waning tomato crop late in the season and leaped in to fill the void.

  2. Long time reader, first time commenting. Thank you for all you do! I just want to add my two cents worth on this topic. 🙂

    My husband and I planted everything we could for our summer veggie garden in SIPs this season, as we moved mid-summer and needed to haul the whole garden with us. We’ve been experimenting with SIPs for a few years. This season we used some of the name brand and generic models (Earthbox, Eezy-Gro, Mainstays SIPs from WalMart) as well as the DIY varieties (5 gallon buckets method). We have 10 tomato plants in SIPs, of 5 different varieties – Roma, Big Boy, Green Zebra, Super Sweet 100 Cherry Tomatoes, and Black Cherry Tomatoes. I did not use any landscape fabric to keep the roots out of the reservoir this season, and sure enough the roots made it in there. The tomatoes taste as perfect as ever, and we’ve already gotten over 200 cherry tomatoes off of each cherry tomato plant, and they are loaded with more. We started harvesting earlier than ever, as well. With our short season in Colorado, it has been terrific to have so many huge tomatoes as well as the abundance of little cherries. We’ve had enough tomatoes to eat with every meal, give away to friends and family, and to can tomato paste twice so far. I’ve never had such a productive harvest from so few plants. I will be using the landscape fabric when we build our permanent sub-irrigated raised beds, to make cleaning out the beds easier later. I’ve not had a problem with unhealthy plants or unproductive plants when the roots reach the water – only a problem with getting all the darn roots back out of the reservoir when the time comes for clean up! I think it does help a lot if you are not using white buckets or containers that the sunlight can reach through. Just some things to think about. I hope it helps! 🙂

  3. I use a SIP for my Sasha’s Altai which is a Siberian tomato and very cold hardy. I used 2 dry wall mud pails to make the SIP so they contain about 5 gallons of my own compost. I added some ground egg shells for calcium. The tomatoes taste good and there is no blossom end rot like I have with my tomatoes in pots. We live quite far north and have cold nights and short summer and I find the toms in pots generally have fruit earlier than the tomatoes in the ground.
    So far I like the SIP better than large pots and I will make more when I find more pails.

  4. We did tomatoes in 2 SIP containers and 3 upside down planters. We did them as a pilot/project with our left over seedlings, the less promising ones.

    They performed way better than we had expected and plan on putting some more together for next year. I didn’t find any difference in taste between those in soil and those in SIP, but it’s been a bad growing season for us this year. Weather was very yucky!

    Tks for sharing the idea on the cloth layer. I’m picturing you put it down at the bottom over the holes and earth wick?… i’ll do some digging and experimenting next year ;o)

  5. We are doing pretty well with our tomatoes in SIP’s. One was a yellow pear tomato, the other a cherry tomato. The weather was moderate this summer, which made watering simpler, no distress between waterings. After a couple of years of using organic fertilizer, we tried Miracle-Gro, and it worked great. Next year we’ll put in fresh potting soil, and we’ll try the landscape fabric, thank you for the hint. We have consistently killed calibrachoa in the SIP’s, maybe it is the wet roots? ‘Mousse

  6. I did six tomatoes in SIPs this year. I do have neck high plants with plump tomatoes but they are suffering and it’s been a fight the whole way. While it was a fun experiment I believe this will be the last year we run tomatoes in them. Next year we will be trying out 20 gallon smart pots as the experiment tomato in the two gallon smart pot EXPLODED in growth. I’d not recommend smart pots in dry environments but they’re great in the pacific north west.

  7. I am growing tomatoes in SIP this year. I have had best results with a small hybrid variety (Park Seed Container Choice Hybrid). I have had very poor results with large or even mid-sized varieties of tomatoes. I think if you are going to grow tomatoes in a SIP, you really want a hardy variety and not a temperamental fancy heirloom.

    I’ve also had good luck with herbs and different varieties of peppers in SIPs. I have basil plants as big as shrubs. My cucumbers did ok but not phenomenal, although they are a nice addition and I think I would plant them again. I tried summer squash last year and it did not like the container at all. Next year I want to see if zucchini does better than the yellow squash did.

    I am curious in the picture: Is there any benefit to elevating the SIPs off of the ground? What’s going on with the clamps?

  8. I planted squash in my SIPs this year and struggled to keep them wet enough. I ended up filling them almost every day for the second half of the Summer. Maybe those big leaves pull a lot of water.

    I got a lot of yellow summer squash but not much else. There were a couple butternut, a couple zucchini, and a few acorns.

    I think next year the squash will go back in the ground and I’ll try something else in the SIPs.

  9. i tried 2 sip containers then i put 2 tomatoes in the garden and 2 in the containers. the container tomatoes were a third bigger, and produced a third more tomatoes compaired to the garden. i was hopping for earler tomatoes from the containers but i was happy for the results

  10. I tried strawberries in mine, but can’t recommend it. I don’t think their roots go deep enough to reach the moisture – should have thought of this before I planted them. Next time I think I’ll try bell peppers . . . .

    • Root veggies do well in SIPs if they have enough depth for full development. For that reason, people growing in SIPs often focus on smaller, stubbier varieties. I assume you mean your container is 2 x 4 feet, not inches? 🙂 And what is the depth? At any rate, there’s no excuse for a SIP, whatever the size, to be too wet. If it’s too wet, something is wrong. Perhaps the soil is the wrong type, or there are insufficient ventilation holes. Or the overflow is blocked. Otherwise, even a deep container should be okay. You might want to check out The Green Roof Growers site. They grow all kinds of stuff, even watermelons, on their roofs in biggish SIPs.

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