Ahhh, a subject I have experience in...
First, what not to do: what got me into the hobby again
last year was buying some Dionea. I had forotten about soil
mixtures, but I remembered peat. So, I bought a nice terra
cotta planter about 5-6" deep, filled it with peat, and planted
my flytraps. Although they did ok, they weren't real vigorous.
Then they got dug up by bluejays. While replanting them I
noticed the peat was dryer than I expected, warm, and, well,
it felt dense. I wouldn't want to be planted in it. So, I
dug up Schnells book, bought a bag of sand, and made a 50/50
peat/sand mix. I planted the plants, and put a layer of longrain
live (you could use dried) spahgnum over the top to keep the
moisture in. Plants were MUCH happier with that.
I currently have my plants in an "American CP" planter. It's
an undrained plastic window box about 2' long, 6" wide, and 6"
deep. There's about an inch of pea gravel in the bottom, about
5" of peat sand, and some live moss on top. My flytraps were
real happy in that when they were active, and now that they're
dormant they're still happy. I also have a S. rubra, D. intermedia,
and Barrys mystery pings in this planter. In one corner I have
a small, drained, 2" pot buried (like you saw in the Ceph tray
at C.C. Scott) so I can know the water level in the planter.
Check local chain stores and garden stores. You can usually find
1-3 lb. sacks of sand next to the African violet mix, perlite, etc.
In replanting my flytraps I noticed they had roots going a good
4" or so. A window box type depth is probably ideal. They're
not fussy though. Give them 4-6". If you give them less, I'd
be careful about watering because I don't think they like having
their roots sitting in water.
BTW, using pea gravel as drainage makes the pots damned heavy.
Using sand in your soil mixes is almost as bad. Peter D'Amato
uses peat/perlite for the mixes he sells his plants in because
it weighs less. However, you get a different kind of mix. For
lack of a better word, the perlite mix is fluffier, while the
sand mix is well drained, but closely packed. I prefer sand,
but it is really heavy, which is in issue if you have a lot of
plants, or big pots. If you use perlite definately use life moss
on top, and maybe on bottom, to keep in moisture.
Robert