Don,
With me often it's a matter of economics, and perlite can be very expensive. I did get a 50-pound bag of 50/50 vermiculite/perlite at the local farm cooperative for 12 bucks last week, but then you can get a 50-pound bag of oil absorb made from diotomacious earth for five bucks, and I found it really spaces out my potting mix and absorbs water like a sponge.
Since I've been amending with diotomateous earth oil absorb product, when I water my seedlings, the water runs down through the containers much more rapidly that when it was just peat, perlite, and vermiculite. The diotomaceous earth also swells up and seems to retain water at least as well as vermiculite for less than half the cost.
Another product that works well for me is the baked clay oil absorb and it comes in 50-pound bags for about 3.50. It doesn't retain water like vermiculite or diotomaceous earth, but it's excellent at spacing out the growing medium to provide better aeriation and drainage.
Fire clay is even better since it will not break down since it has been fired in a kiln. Fire clay is a product sold to potters to augment pottery clay. It's also used to produce bricks that can stand up to high heat like in fireplaces and kilns. You should be able to buy fire clay wherever you buy pottery clay or from a brickmaker.
Also, crushed brick works well for the same purpose ... spacing out growing media and improving drainage.
PV
|