What can you scrounge locally (even fossicking where the fly tippers work their foul habit)? Old paint pails with BIG holes for drainage (thumb-thick and about five of them) would give you your depth and the handles made shifting them relatively easy. Which would be useful as Saffron grow better if they're repotted annually - and have a rich mix with excellent drainage. If the plebeian past of old cleaned paint pails is a bit much then making a surround of recycled planks, refreshed with some paint, would disguise them and would hide the pot feet or the pebbles you stand the pots on to help them drain well. You'd probably get five to a pot. That would take you about 3.5 40L bags of potting mix. Less, if you plan to add sharp grit, about 3-5mm diameter, to the mix. I don't think I'd go for a washing machine bowl. They tend to have peculiar drainage problems (but that might just be me). And old tyres in stacks aren't as clever as they're made out to be. :-((( Old wooden boxes lined with thick plastic (such as the potting mix bags opened out and suitably holed) are a possible, if you can get them, and might even be 'art-y'. Or ancient polystyrene chilly bins/eskies - whatever it is you call those things with handles for taking drinks and ice-packs to the beach. And remember that they need a dry dormancy (although that might not be a problem with the heat waves the UK has been enduring in parts). As you have a reasonable number of bulbs you might want to risk a few in a shallower container, too. Just to see if you get flowers AND healthy bulb increase. Hope they do well for you. Those sharp orange-red tassels are something I look forward to each year. Pretty as.

Saffron is actually a fall-blooming crocus. Mine always blooms in November. The blades stay green all winter and die back in the spring. It's supposedly hardy to zone 6a, so I would give it a try. You don't get much of a harvest (which is why saffron is so expensive), but you don't generally use a lot in cooking and it's fun to say that you grew it yourself.

I'm no expert, but from what I've read, the answer is NO. Here's an article on Saffron. There are different varieties of Crocus Sativus, however. Here is a link that might be useful: Saffron

The crocus mentioned as being a poisonous one has very long stems to the blossoms. One supplier sent me a note to tell me thay were fooled into that type too, and said to plant them in an area where you just want fall flowers to grow. Because they grow so tall they fall over easy. Saffron crocus flowers only grow about 3-6 inches tall with their stems. I used a 1/4 inch holed steel mesh screening. The squirrels didn't bother digging but VOLES do! They voles ate up all my tulips and crocus bulbs everywhere. These saffron crocus are planted in a small area with that screening as a big box under the bulbs. I also added some rodent repellent which is very abrasive bits of small stone that hurt when the rodents dig into it. I added bone meal and the second planting has just now shown up as green leaves only. The saffron crocus has very little smell and taste the first couple of years, as it matures it gets a bit stonger. Only issue is they multiply fast, so every few years you need to dig them up and seperate the corms. A good organic fertilizer high in phosphorous will help to get more blooms and later on taste. I got my recent ones from Richters, who sell quite a large selection of herbs and plants. You usually only use a few stamens per recipe. Too much in a recipe and it can get medicinal tasting.