They were a few left overs from last year, I thought you could save any spuds and they'll grow again once planted. I stored them in cool, dark cupboard but obviously did something wrong.
It's not ideal, Marty but I think it's as good a place to start as any. I started this way and still pop some in that have gone to chit from the bottom of the potato bag. The risk you have is disease, so keep them away from each other when you plant. If it works and you fancy doing more next year, think about buying some disease-free seed potatoes.
The important thing is to dig them into a trench as deep as you can and then gradually fill in the trench as they grow. The spuds grow on the green stalks you cover up later. I grow mine in bags or even old dustbins with holes through the bottom. Just because it's then very easy to dig them in deep and keep covering up during April/May/June. But as Dorset has already said - you must remember to keep watering them. Also would help if you can add organic matter.
On organic matter, you don't need to buy it. Here's some things you can do:
1. We have a polystyrene wormery which keeps stuff warm and doesn't release smells to attract rats. ALL waste food goes in there*. I put a seed tray beneath (one without holes) under the drip hole and every week you'll have a yucky brown liquid you can add to water to feed them. After a year you can dig in the finished worm matter from within. It goes dark brown.
2. Collect the green of nettles, or of you have it comfrey. Fill a bucket to the top and submerge it in water. After about 4 weeks it turns into a very smelly brown liquid. Dilute with water again for a great feed.
3. Compost garden waste in a heap. If you can, cut stalks etc. up small before adding. Grass cuttings are the easiest but you must add about 50% brown matter too (wood chippings; newspaper; torn card). It's composting when it gets hot (you can feel it and see steam rising). Turn it over to add more oxygen after 4-6 weeks. When it cools you have a great compost.
Good luck!
* EDIT: Just remembered, don't add citrus peel. Everything else though: potato peelings; pepper stalks; onion skin... everything. It will even take cooked food if you don't complete your meal. We are veggies and give ours to our hens, but it would take anything.