I don't know who came up with the idea to spray rosemary with milk to combat powdery mildew, but it works extremely well. I am zone 4 and move my numerous rosemary shrubs in my greenhouse for the winter. Powdery mildew has always been a problem in the past, but especially bad this year because of a warm winter (even for Minnesota). Its very hard to keep the humidity down. Washing the plants just wasn't cutting it this year. I googled the subject Sunday and came up with the milk idea. My numerous rosemarys were badly infected, but one application of 1 part low fat milk to 6 parts water along with a 1/2 tsp of baking soda per 1 qt cleared it up. It did happen that the day was sunny which was mentioned as part of the cure process. I'm not sure about that. Milk, go figure.

From my experience: Tarragon - don't be fooled by seed catalogs, tarragon from seed won't be French Tarragon, so make sure you get a cutting or a plant. The leaves should smell of licorice to be the "real thing." Rosemary from seeds requires bottom heat, maintain the seed tray at or above 70 degrees to get germination. A slip cutting is MUCH easier to start, or get a plant from a local nursery. Marjoram, Oregano, or Mint - get a plant or a cutting, and check the flavor of the leaf. (there are lot of varieties and some are tastier than others) Lemon Verbena - buy a plant. Be prepared for it to make into a scraggly looking plant that drops its leaves easily and probably won't overwinter in your zone (never has here in zone 6b). I've stopped buying the plants as Lemon Balm grows like crazy here and is a more attractive looking plant. Cilantro, Parsley, Dill - all three of these can be started from seed, but its funny that the FIRST planting always seems to have spotty germination but if you let that plant go to seed and reseed freely into your garden you will never lack for plants again.

The parsley and two chives could share a pot if they must, because at the least they will not completely shade each other out. They can all probably overwinter outside, and the parsley is a biennial, so it will probably only live for two years, leaving the other two to fight it out. I think they all like similar conditions as well; they're realy not "Mediterranean", I guess. It would be worth giving each of the chives its own pot if you have enough, though, since they usually winter over quite well. The basil, cilantro, and dill all tend to get taller, so would probably look OK together in a pot set on the floor. They are not perennials, but might reseed themselves in their pot with a bit of encouragement from you. Dill is easy to grow from seed, and if you collect seed from your plant you could sew some in your garden as it empties of other plants. Ditto with cilantro, which tends to bolt in hot weather, so you won't have it that long otherwise. Rosemary and thyme would probably be happy together, as they are both Mediterranean and like similar soil conditions. They are also, in your zone, fairly slow growing, and will not challenge each other too much. Depending on the kind you have, they will probably need to be brought inside for the winter, but that is no absolute guarantee they will winter over. My best luck with each was by purchasing the most winter hardy variety of each I could, and then wintering over thyme outside in its own pot, and rosemary in the ground on the South side of my house. Lemon balm is really an outdoor plant and will probably reseed all over the place for you if you plant it outside--if you like the tea from it I would plant it in some semi-shady spot on its own and let it do its thing. In subsequent years you can then have little adventures hunting down your lemon balm whenever you want tea. It is a cooling herb and is great in summertime drinks. Oregano does so well outside at the edge of the garden that it would be a shame to confine it. It's not really invasive, and does better at establishing itself in regular garden soil than most of the others. It will produce a nice supply of herb for Italian dishes like spaghetti...plant it near your tomatoes so you don't forget to gather some! I have had it winter over for me quite nicely. There are two kinds of chamomile; one is a perennial and the other is not. I've never had much luck with either one, but if you only have three pots my guess would be to put it with the chives. Everyone else is correct; in time, if the plants survive, they will all want their own pot, and will be much more productive for you if they have it. With limited land, space, and pots, though, sometimes a bit of triageing is needed.... ;o)

I don't think I'd move a large plant of any kind if I didn't have to. You might be better off buying a new plant already growing in a can for your deck arrangement. Or, if your large Rosemary has started growing roots off one of it's branches you might try cutting it off the mother and transferring it instead. Of course, some of what I've said depends on one's definition of what is "large."