Are the herbs fresh or dried? If fresh, start with 1 c. chopped herbs and add that to your olive oil. You can basically pack as much of the fresh plant into the oil as will fit, as long as you cover it with a good half inch of oil once its packed. Otherwise the wet herbs hitting the air can go bad or grow fuzz. If that happens, I find that you can scrape off the top layer of plant/oil and cover again with a half inch of oil. If you're only doing two weeks it should be fine. For dry herbs, you can powder the plants (in a coffee grinder or blender) and use about a quarter of teh volume you would have used fresh.

Hope that helps!

BTW, the combo is good; rosemary for scalp health, calendula for soothing the scalp and warm highlights.

previously posted in another thread, here

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Drop half a cup of fresh herbs into a glass jar and pour one cup of your preferred oil over it. Place this jar in the sun for about a week ,shaking it once a day. After a week "squeeze" the oil through cheesecloth. You can then further blend this oil with a carrier oil
of your preference for application.

OR

Place the herbs into a dutch over pot or, even better, a crock pot. *for each half cup herbs you will add one full cup of your
preferred oil. Simmer or "cook" on low for 2 to 3 hours. Cool it and "squeeze" the oil through cheesecloth.

OR

Infuse the herbs in alcohol for a few days (vodka, brandy or gin are best choices because they allow for the proper alcohol to
water ratio needed for extraction of all the herbs oils), If you are, somehow, averse to actual drinking alcohol, I've heard you
can use vinegar but will need to warm it before pouring into the jar. *cover herbs entirely but leave headroom, as if you
were canning, in the actual jar.

.................

Rosemary, Patchouli, Lemon, Tea Tree, Ylang Ylang or Basil: Oily hair

Rose and Chamomile: Fine hair. Itchy Scalp

Peppermint, Myrrh: Dry Hair (also stimulates growth)

Clary sage: All types of hair & Dandruff treatment

Lavender: Good For all types of hair and scalp