Alternative to crocks in growing containers

Hi folks, quick question;

anyone tried using something like felt or old fashioned underlay to line the bottom of growing containers?

Thera are 2 reasons why I ask;

1 - I have dozens of 20 litre containers and I do not relish the idea of messing about with such a large amount of crocks (I don't have any anyway) and having to sort them all out again when emptying containers (spuds).

2 - putting an inch or two of crocks in means that much less growing medium in effect making the container smaller which is a concern for spuds.

I have tried filling some tubs using a small patch of heavy felt like cloth to cover the drainage holes and watered it copiously, it seems to drain ok.

Anyone tried this, or heard about this being done.

(I'm a novice BTW)

The crocks in pot bottoms is a traditional way of 'doing things'. I myself have no clay pots so I have no broken ones to add to other pots. The idea is simply to keep the drainage area open, so yes, pieces of weed barrier or loose woven burlap (not underlay) over the drainage hole will work just fine, as will some scrunched up polythene or whatever else will keep the soil in and let the water out.

As Trillium mentioned, I keep any small bits of weed suppresant I may have and pop those in the bottom of any containers I use.  I've used polystyrene on pots that are really big and I don't want to waste too much compost in them.  Polysturene helps bulk the bottom out and helps drainage.

Thanks all, will see how it goes this season.

I might go with the corks, reckon I need about 50 in each tub at 50 tubs that's 2500 bottles at £4 a bottle, a snip at £10,000 - will I be able to cope? 

I just use  a bit of fleece - I  usually have some that is torn in a corner of the shed - good for lining baskets as well - in this case the cheaper sort works better. 

Small charcoal chips work well. They are totally fungus resistant and will hold water. If you can find someone nearby who makes charcoal, they may be able to supply pieces sieved at 1/2".

For the top of the pot, bits sieved at 5mm down to 3mm are useful to sprinkle on the top. Here their afungal characteristic is useful. Damping off is a problem, and we found that charcoal chips on trays of Basil seedlings completely stopped the problem.

Small charcoal chips work well. They are totally fungus resistant and will hold water. If you can find someone nearby who makes charcoal, they may be able to supply pieces sieved at 1/2".

For the top of the pot, bits sieved at 5mm down to 3mm are useful to sprinkle on the top. Here their afungal characteristic is useful. Damping off is a problem, and we found that charcoal chips on trays of Basil seedlings completely stopped the problem.

An excellent idea - I suppose you could use the small dusty bits from barbecue charcoal as well. Thnaks for the tip 

Thank you, oldbean