Is late April too late to plant herbs from seed in the US Pacific Northwest?

Question

I am trying to plant an herb garden in the Puget Sound region (USDA Zone 7b) of Washington state. I wanted to get some perennial herbs going from seed, but I am wondering if it is too late now? (late April/ early May) I have access to a heated greenhouse and would be growing starts in a 72-cell seed tray, rather than direct seeding.

The herbs I was planning on incorporating into the garden are listed below. Can anyone tell me if there are certain herbs on here that I should not grow from seed at this time? Which of these would I have to get going from starts now? (I'm hoping that the herbs that can survive as perennials in this area would be able to survive the winter outdoors).

• Anise
• Anise Hyssop
• Arnica
• Bee Balm
• Black Cumin
• Calendula
• Caraway
• Catnip
• Dill
• Echinacea
• Evening Primrose
• Feverfew
• Horsemint
• Lavender
• Lemon Thyme
• Marjoram
• Motherwort
• Mugwort
• Pennyroyal
• Salad Burnet
• Sorrel
• St. John's Wort
• Sweet Cicely
• Tansy
• Tarragon
• Thyme
• Valerian
• Wintergreen
• Winter Savory
• Wormwood
• Yarrow

Answer 1

Just a quick answer to get started, based on my experience. I never lived in the Puget Sound area, but know it quite well. Will continue to fill in as I have time.

Short answer: Get started now, this is the perfect time. On a quick glance I see no plant that you would be too late for, but I haven't sown/planted all of them myself.

• Calendula will be fine. Consider sowing outdoors where you want it. Reason: Not too keen on transplanting in my experience, but possible. If your winters are really mild, it may continue blooming even during winter, but the plant will be exhausted at some point. But it will self-seed, thus establishing a population at the given location. You can also harvest the seeds.
• Dill is definitevely not a perennial, once it has produced seeds (also edible!) it will start to die. But establishes itself if allowed to drop its seeds. For a continual harvest of fresh dill, you have to sow in intervals from April through August/September. It will be happy in pots, but it's easier to just take a small handful of seeds and shatter them where you want them. I usually do this sparingly in my vegetable patch, the plants will rise over the other crops and are slim enough not to bother the rest. (Looks good, too, IMHO) Fallen seeds can overwinter and germinate in Spring.
• Lavender and (Lemon-)Thyme are a bit fussy to grow from seed, but it's doable. Here sowing in pots is an excellent choice because you can monitor them better. You can put them outdoors as soon as March, but a greenhouse won't hurt. Hurry up with these, so that they will have plenty of time to grow until Fall/Winter. As true perennials, you may have these plants for years. For Lavender I'd suggest buying one plant that you like - they come in a bunch of varieties, so look, touch and smell when choosing - and propagate small cuttings if you want more.
• Majoram is a bit cold sensitive. So either sow in a greenhouse now or wait until the last frost - which I suppose is about now in the Puget Sound area? - but not later than June, especially if you want it to survive winter. It is technically a perennial, but a cold winter will kill it, therefore some gardeners choose to grow it as an anual. It's cousin Oregano is much hardier. There are even cross-breeds available that claim to give Majoram the hardiness of Oregano, but they also have a more "oreganoish" taste.
• Sorrel is probably not a good candidate to be started in small pots. It develops roots (rhizome) that can reach down 1.5 m / 5 feet, so sow where you want it and it will be a perennial. For immediate use, sowing in pots is fine, but it will have difficulities long term. A spot in the semi-shade with enough water and acidic soil (6) will keep the leaves more tender.
• Valerian seedlings are cold-sensitive, so start them in your greenhouse or outside after the last frost. This is a true perennial, but plan for a slow start - you can't harvest roots in the first year or two. The plant will get rather large (so choose the spot wisely), but grows slowly.
• Salad Burnet is another candidate that hates transplanting - you can literally watch the leaves shrivel up and die if you attempt it on a sunny day and don't cut large clumps of soil around it (ask me, how I know...). If sown in trays, always transplant the whole "brick", never pull it apart. Once established, it is a hardy perennial that even might provide a few green leaves for your kitchen in winter. Clumps can be divided after a few years, IMHO easier that starting them from seed. But sowing is possible almost year round, in winter in an unheated greenhouse, else outside.
• Bee Balm now, that might be a tad late to sow. But as Monarda typically won't bloom the first year anyway, I'd say sow them and give it as much time as it needs.