All of those should do well in full sun and freely draining soil (make sure the planter has good-sized drainage holes to prevent soggy conditions). Little fertilizer should be needed, maybe some organic/slow-release amendment when the soil is prepared.

Since this is a forum for discussing medicinal use of herbs, you may get more answers in the Herbs forum.

Thanks so much for your advice! My apologies for being sort of off-topic, I somehow just saw this one and missed the Herbs forum. I will re-post there.

Liz:

Are you referring to the white wild yarrow? If so, they thrive in almost any rich soil as Eric said. However, red clover likes a very sweet soil which you obtain by adding lime in abundance. I don't believe yarrow would do well in a sweet soil.

I'm just going by my experience at farming as a kid and my knowledge of herbs as a professional herbalist.

HerbDoctor

None of these herbs need any fertilizer or rich soil of any kind.

Red clover is a nitrogen fixing plant and can grow very successfully in poor soil. In fact, it is used to make the soil it is grown in better. As I mentioned in the herbs forum, I would suggest direct sowing a small patch, if possible if you are looking to harvest flowers for use. A plant or two in a pot won't give you enough. And unless you have wildly acidic or alkaline soil -- which you shouldn't in a container, skip the soil conditioners. That's just going to get you in trouble.

Yarrow grows VERY successfully in some of the poorest soil I have. It is the very spent soil of a garden bed over used by the previous owners. Instead of renovating it, I turned it into an herb garden. The herbs love it - but the vegetables I originally tried there did not. Yarrow here grows in lawns, old pastures, cracks in sidewalks - wherever it wants. It tolerates a wide range of conditions. Here it tolerates mowing, foot traffic, heavy clay soil, lean soil, well-draining soil, and little water with equal ease. I never had to buy any yarrow. It was in the lawn (along with oodles of other "weeds"/herbs) of my 160 year old house. My lawn is quite the herb garden!

I've had poor luck with roman chamomile, which you said it was in the herbs forum. I like the german chamomile much better. Easy to grow from seed. Some people even use the contents of chamomile teabags to start plants! German chamomile needs only average soil, average moisture and full sun like the other two mentioned.

FataMorgana

I have The German chamomile at home. Both leaves and flowers are used for making tea. The leaves can be more bitter than the flowers. It is easy to start form seed. . Start seeds indoors, about 6 weeks before the last expected frost. Chamomile seed needs light to germinate, so simply scatter the seed and press firmly onto the soil, but do not cover the seed with soil. Seed should germinate in 7 to 14 days. You can also direct seed German chamomile outdoors. YouâÂÂll get better germination if you do this in the fall and let the seed stratify over winter, for a spring crop. I have other herbs like thyme, spearmint, basil, chive in my garden. I used to use the spices and herb blends for cooking.

Here is a link that might be useful: herb blends