I think sedum might not give you much return for the cost of using them to make compost. The whole idea of compost is to recycle things from your home, yard and garden that you otherwise would have thrown away. Like fruit peels, lawn clippings, spoiled fruits and vegetables, etc. Those things are all considered green for your compost. Browns would be leaves, shredded newspaper or cardboard, and eggshells. Mix the greens and browns together and you have a garden amendment that cost you nothing and helps to keep landfills from being loaded up with things that are still useful. And these items are all free. I wouldn't buy seeds to plant something just to make compost out of it.

You may be thinking of the principle of 'green manure' where the garden is sown with winter rye, red clover or hairy vetch, plants with short life span, that also fix nitrogen in the soil as they grow. They are planted in fall and the roots help to maintain the soil through winter and in Spring they are turned under to fertilize the soil for planting a garden.

If you have a garden you don't need to grow anything green for the compost pile. As you trim and thin plants through Spring and Summer, put your trimmings in the compost pile. Add all of the grass clippings, junk mail, newspapers, cereal boxes, kitchen waste, leaves, stems, sawdust(from non-treated wood only), wood ashes, chicken poo, cow, horse, goat, sheep or rabbit manure.

Things to avoid in your compost: grease, meat, pine, citrus, pet waste.

"Things to avoid in your compost: grease, meat, pine, citrus, pet waste."

All of the above have been composted in my pile (although I try not to make a habit of using pet waste). They'll be fine in moderation and in a working pile.

tj

Broad beans (fava beans), being a legume, improve the soil. They're prolific, delicious and the stalks create loads of biomass for the compost. Probably wait till autumn to plant though. Corn/sorghum's a great summer composting crop, with bonus food. Buckwheat, phacelia, lupins, annual clover, field peas...I don't grow anything specifically for my compost except comfrey; everything else serves a food/nitrogen-fixing/soil-protecting/beneficial insect feeding role before it ends up there. But it all ends up there!

Pippimac - I couldn't have said it better. The only thing I grow mainly for composting is comfrey and even that is great bee food. As for trying to use sedum as a compost ingredient I think that would be less than a great idea. What you need is something with deep roots that brings nutrients up from deep down and/or has plenty of top growth wich provides lots of 'greens'. Sedums do neither. Sedums of the type used on green roofs are very low growing grovelly things with very shallow roots. That's why they can grow on roofs. They would be a nightmare to harvest. They also have the potential to grow from the tiniest piece. So any bits that escaped thorough composting could regrow and you'd have sedums coming up everywhere.