Saturday, January 24, 2009

Solutions to a Different Problem

While looking for the cost of organic tatsoi on the web (research for my New Year's resolution), I ran across someone who wrote a thesis in the '90s about raising vegetables on roof tops. Though it didn't give me the answer I was looking for, I couldn't help but read it.

The article was a bit dry, not that that would deter me from reading it. His beds had soil that was only 3" deep to keep the roof from collapsing, but he did succeed in growing things. Sadly he concluded that it wasn't an economically viable enterprise. The useful tidbit that I got out of it was from his use of soil blocks.

Since I'm trying soil blocks this year and they can be eroded by watering from above, I've been contemplating how to water them. I had decided to just bottom water and hope they hold up. I don't like the idea of misting the little seedlings which is the recommended solution. It promotes disease in our humid area. However this author watered with a capillary mat. Yes! That is the perfect solution. I think even my husband can take care of my seedlings with a capillary mat.

I'm not using the author's route to a capillary mat which was buying a commercial one. Surely one would be easy to make with materials at hand. I have lots of cloth of different kinds: leftover bits from making things, old t-shirts and the like. I'm sure I'll find something that will prove appropriate after a little bit of testing. Before testing however another web search was at hand. What do other people use? I've found the most often recommended cloth is an old acrylic blanket.


  1. Daphne, funny you should bring this up. I have been telling a lot of people about using soil blocks lately- I have used them for a few years and love them. Watering is not a problem, if you make wooden trays that are open on one side. I also have a bigger wooden container that can water my bigger wooden flats that hold the 2" sized soil blocks- I have tried to water using capillary mat and the roots go right into them- which in my experience, defeats one of the great purposes of using them in the first place- which is little disturbance to roots;very useful for plants that are usually direct sown. You can check out all this on my blog if you want, click on label 'tools' to find the directions for making the wooden flats and happy gardening!!

  2. Ah a flaw in the system. I wonder if newspaper would work. Some people have used that as a capillary mat (though I haven't read about it being done with soil blocks. I checked out your page, thanks. They are very close to the size the Elliot Coleman makes. I'm going to use my plastic flats that I have for now and leave a space at the end so I can get them out easier. I really don't think my husband will be able to handle misting blocks, not to mention me :> I'll have to experiment to see if newspaper has a strong enough capillary action. Otherwise it will be bottom watering.

  3. Oh, I am so interested in this Daphne. Way to do the research and find that roof top guy. It is disappointing to find it not worth it. If the object was just to grow something ornamental rather than food I bet there are plenty of plants that would work, like sedums. I think newspaper is a good choice, but wonder if it would work as well as the blanket material. How about something like a disposable diaper with that lining that keeps baby bottoms dry, or even coffee filters allowing wet without the roots growing into it? Just a thought.

  4. Daphne,

    Making the wooden flats and setting them in a standard plastic flat does wonders for those that don't like to mist! Eliot Coleman (nice guy, by the way :) in his show Gardening Naturally (I found the VHS version at my library and had to dig out my VCR!) takes his wooden flats and puts them into a plastic tray, fills it with water so the little valleys are filled then covers them and leaves them alone until they germinate :)Now, I have found that if the plants are on a heat mat, I need to watch them for drying out- but misting them is not needed very often. I usually just soak them by adding more water for a bit if they get dry. Eliot Coleman, in the video, didn't put them on a heat mat or under lights- he set them on a counter or refrigerator until they germinated then they went under lights.I'm sure there were exceptions to this, of course.

    I've tried newspaper. I took the newspaper and draped the edges into a trough of sorts that I attached to the edge of my staging in the greenhouse. I didn't like the outcome. Roots still grew into it, moss everywhere and some mold even where a problem. I tossed it all out. Hope this helps :)

  5. Hm, hope you find the solution to your problem. I like that you are looking into re-purposing stuff instead of buying something new (and non-biodegradable)! Good luck.

  6. Frances, Isn't the internet a wonderful thing. You can find so many things. My kids are of an age that they grew up with the internet and take it for granted. Sometimes I wonder how we lived without it.

    Tessa, hmm even newspapers are a problem? Well I may just go for bottom watering. I'm not going to build anything yet. If the plastic trays I have had for years don't do well, I'll do that next year. Thanks for all the info.

    Karen, I'm always trying just to use what I have. I almost did that with the soil blockers but wanted something that would hold together for a long time.

  7. Good luck to you Daphne! I'm glad you're set on using what you have on hand- good for you. I too was on that same road, I just happened to have some wood that I could use for the flats because we were working on the house at the time- I lucked out! I did have to purchase a few things like some nails, I believe. Happy Gardening :)