lovage and salad burnet — I think the mature seeds on both of these are brown. Cut off lovage seed heads and store in a paper bag. I scrape salad burnet seeds into my palm, and into another paper bag. Be sure to label all seed containers.
curley parsley – This is a biennial. Parsley is hard to germinate, so I just bend the seed head over the area I want new plants in, and let it plant itself.
dutch lavendar – haven’t collected from this.
chives – seeds are black when mature, cut off heads into paper sack, shake
seeds out and store. They’re only viable for one year, I think.
st john’s wort – I haven’t collected seed from these, but I’d guess you should wait until the seed pods turn brown.
sweet woodruff, >rosemary, >aztec sweet plant, & roman chamomile – I don’t know
lemon thyme, thyme – I’m not sure, although thyme, at least, does self-seed.
greek oregano, oregano – I assume when you can shake some pepperlike seeds from the seedpods.
french tarragon – does not set seed.
borage – get the black seeds from the seed pods before they distribute themselves. Peek inside.
corn salad valarianella, >grapefruit mint, & pineapple mint – I don’t know
sage when you can shake seeds out of the seed pods.
pineapple sage – does this set seed? I’ve never seen it or seen it offered.
lemon mint – this is a monarda, I believe. shake the dry seed head over an envelope.
catmint – I don’t know. I grow it, but don’t collect seeds.
candy mint – never heard of this one.
comfrey – I don’t collect seeds from this plant, it spreads by itself.
cinnamon basil, sweet basil – before frost, shake the seed heads inot an envelope.
marjoram – this is frost tender; before frost, shake seed heads into envelope.