Good call! I've never actually heard of solo cups, we know them as red cups or beer cups, but I think they're mainly used for college dorms. For gardening I've always used plastic gardening pots. They last for decades. I'm using some from my late grandfather and they're just as good as my newer ones. But ultimately I hope to replace them with permanent pots made from durable hemp plastic, when that's more available at a lower price.