New Washing Routine?

So, I usually use THIS recipe for me dreads that Soaringeagle the great gave me. I have dandruff prollems. yargh.:)"in a gallon pitcher mix:a good squirt of bronnerssome baking soda (3-5 tablespoons)5-10 drops teatree oil10-30 drops rosemary oildump over head lather up (wet hair with cool not hot water)rinse with freeeeeeezing cold water"I use that evvvvery Sunday, so my hair is sofresh and socleanclean for the coming week.But, lately, my head has been real itchy for some reason. I think maybe I should be washing more often? I just don't know where to start. With me in me kitchen I have: Lavender Dr. Bronners (I will invest in Tea Tree soon), bakin soda (that huge awesome bag from Costco), tea tree oil, sweet orange oil, and lavender oil.My mom obviously loves lavender. Not me so much, but its what we have. :|THANK YOU!
updated by @junebug-johnson: 01/13/15 08:49:05PM

Have you used ACV at all? I tend to get real itchy and I've found that rinsing with it once a month helps a lot. You have to use it separate from the baking soda mix though, like right after rather than IN the mix. I have a big 32oz squeeze bottle with the pop-up cap on it that you would normally use for drinks. I add about an ounce of ACV and fill the rest up with water. After I'm done with my baking soda wash I'll make sure I've rinsed really good and then I'll pour the ACV mix over my dreads and my scalp real good. I let it set for a minute or two and then wash that out real good.It leaves you with a faint vinegar smell that lasts an hour or two but if that really bothers you then you can add a couple drops of a nice smelling essential oil to the ACV mix to cover up the smell.