They will definitely survive in zone 9.
But the best time to start them from seeds is in the spring time. Tolerating and surviving winter cold is one thing growing in the cold is another. But if your night LOW temps stay over 65F, you can start them now. Then again, it depends how warm or how cold your winters are.

But then what is to lose here? a pack of seeds? Go ahead try! life is an adventure.

I'd go with planting already growing herb plants if you want them to help in the garden, and they will survive LA's version of winter just fine.

I'm sure they'd both grow fine in your winter. But I wouldn't set too much store by their protecting your vegetables. They don't appear to have any effect whatsoever in my garden.

In Z6, most rosemary dies in winter and will not return again. I grow it from primed seeds, as its had to germinate in seed form.

I'm glad that flora mentioned it, because I was going to say the exact same thing.

Rosemary will get huge - they grow it for hedges in LA.

The whole "companion plant" thing is an untested garden legend.

Rosemary will survive in colder areas apparently if the soil is well draining. I have been in Santa Fe, NM with the ground frozen solid standing looking at a 3+ foot rosemary bush. It was too large just to be a plant as it was at least the 3+ feet tall and probably a little more at the top tapering to 18 inches at the base. There several that were not quite that tall in the area we had to park in.

I would also suggest getting potted plant starts. I have yet to grow a mint from seed that I would eat. The joys of both of these herbs are in cooking and eating not so much for the bug repelling. I would say that rosemary is now being sold and used as a bug and anti-fungal treatment and used in this way makes perfect sense. Green Light is the company I know of that is producing it. Both these plants have a great diversity of varieties so do some research and choose what you are most interested in. Right now is a great time to root rosemary cutting in Texas if you are the adventurous type.
Happy Growing David

I have a question along these lines & thought it would be proper to bring it up in this post rather than start a new thread. What about Lemon Balm? Would it survive outdoors during a Z6b (Middle TN) Winter? Worst low temp probably only a few days of 15-20. Otherwise, average low of about 30 or so. If it wouldn't survive in these conditions, what's the lowest possible temps it can stand for long periods (would let me know where I would need to keep it; if storage closet would do or if it would need more warmth)? Also, will it need constant or much light during the Winter to survive? Any & all help appreciated. A friend has offered me 5 baby Lemon Balm plants & I don't want to take them if they will just die in my care.

Thanks - Steve

tn_veggie_gardner,
Most probably, LB will overwinter in your area. Its top may die but it will grow back in the spring. I am in Atlanta Ga. Our winters can get as cold as 15-20F as well, and LB will survive fine.

I did not mean to imply that I think herbs have no medicinal or insectifuge uses. Clearly they have useful chemical constituents which can be made into various effective preparations. But simply growing rosemary and mint in your garden is not likely to do much for the veggies. In my garden the rosemary is actually a favourite hiding place for snails, my major pest, so it clearly doesn't bother them! Anyhow, go ahead and grow them - I'm sure they can take LA winter weather. Rosemary is very easy to grow from cuttings so if you know of a bush get a bunch of twigs and stick them in the ground. Some will grow.

cool...thanks, cyrus! =)

"Arp" is a very hardy Rosemary, it survived one of the coldest winters we've ever had, the temp dropped below 0 Fahrenheit a couple of nights.