Thanks for your comment. I’m not sure whether you mean that you weren’t successful actually making the balls, or that the seeds didn’t come up. If the latter, I’ve got a couple of tips:

- plan “deployment” in early spring, during a long rainy period, so that when the seeds come up there will be regular water until they get established. Don’t know if that’s an option in LA – we have lots of rain here :) Seedlings will die without water. So if it’s not raining regularly and you really want the seedlings to live, someone’s going to have to get out there with a watering can.

- Look at what thrives and spreads naturally around you, and use seeds from those plants. Sometimes native plants might be suited to your region or state, but not necessarily an urban landscape. For example, lots of commonly-sold BC native plants grow in our woodlands but they’re not exactly adapted to the dry, open city.

Hope this helps. Keep me posted on your progress.

I would agree that no fertilizer needs to be added. And I agree that, in general, seeds contain everything they need to germinate (except water and sun, of course). But they do need something to grow in. And often, at least in guerrilla gardening, seedballs are used in situations where the native soil is quite lacking (old industrial sites, empty lots, etc.). So the compost would provide a bit of soil for the seeds to root in.

As for the microbe question, sure, compost is full of decomposers. But not to the exclusion of other microbes. And I know it doesn’t prevent seeds from sprouting – I’ve seen the results! Also, how would a seed germinate in a native setting otherwise? That’s my thinking, anyway. I always seed in compost because I don’t see the point of buying potting soil.

That said, you want to use “finished” compost – stuff that is no longer heating up and decomposing. I suppose you could use sterile seed starting mix too; the point of the compost is to provide a rich growing medium.