Thanks very much for the kind words!
If you have a turkey baster handy, I think it is totally fool-proof.
Hey, it works for me, after killing whole TRAYS of seeds!
You might even be able to gauge what an "average" watering would be, from experience, if a mat got all-the-way-dry. Probably around 4-6 ounces of water. I hardly ever let my mats get all the way dry - I'm an eager-waterer.
(Making my mix coarser and more open helped prevent over-watering too, but then you have to water frequently if there is no bottom-watering "reservoir".)
What I like best is that you can
just look at the mat and know how dry the soil is at the bottoms of the cells or plugs.
No - that's wrong. What I like best is not having to call the plumber every time I bottom-water!
There are some photos here:
http://garden.org/ideas/view/R......
P.S. This link is where I ramble on at length about adding screened pine bark mini-nuggets or "grit" to potting mix. ALL the ideas in there (I think) came from Al / Tapla. He's the man!
http://garden.org/ideas/view/R......
P.P.S
I don't know if it is
necessary, but I always put some cut-up strips of flannel into a few of the grooves or channels in the bottom 1020 tray. I want to make sure that the water in the grooves has plenty of capillary contact with the mat, even if the mat doesn't sag into them and its fuzzy surface isn't fuzzy enough to reach the bottoms of all the grooves.
P.P.P.S
I bet a used cotton towel from Goodwill would work even better than cotton flannel. It would be thicker, and hence touch the soil more firmly and reach down into the grooves more consistently. And hold more water as a reservoir.
Touching the soil through a hole in the bottom of each cell IS necessary. If the cells only have narrow slits, you would have to test the contact to be sure you're watering EVERY cell, and/or keep the mat quite soggy some of the time, instead of just damp most of the time.
P.P.P.P.S
If you have left-over odd-size pieces of flannel or toweling, the mat doesn't have to be all-one-piece. The pieces do need to overlap so they share the water evenly. I think that a strip of fabric from a Tee shirt would be plenty to "bridge" the pieces together.
P.P.P.P.P.S
Someone told me that acrylic felt might also work, but I haven't tested that yet. If it does work, I'm going to get a hank of really thick acrylic yarn and use that in the grooves, and maybe in EarthBoxes / EarthBottles. One of these years!
