Unexpectedly Green

I've been doing some dyeing this week, and I've had a lot of surprises...some of them better than others.  One of the nice things about natural dyeing is that most natural colors are attractive regardless of whether or not they were the intended result. 
This week I cut down a few of my Hopi black dye sunflowers and prepared a dye bath from the seed heads.  I was expecting a lovely violet color.  I got a deep spruce green. 

Hopi black dye sunflowers in my garden

The lighter skein on the right is the skein from my previous post.  That skein was dyed in a bath made from regular sunflower heads, and a few leaves and petals, in a copper pot. 

I can't tell you why I ended up with green wool.  My hands were stained purple from the seeds as I tore up the seed heads.  The dye bath was a dark purple.  The skein looked purple for the first minute or so and and then it started to shift to green.  The bath was processed in a stainless steel pot, and I'm sure that there was no contamination from iron. 
I think Ph is playing a large part in my unexpected color shift.  The water that I use for dyeing is softened and has a higher Ph as a result.  I've ordered some Ph papers.  I think being able to test the Ph of my dye baths will greatly increase my ability to control my results.  It should also help me in the development of my own dye recipes. 
Here are the five skeins that I dyed for Ambre Danicour.  They're all Maco Merinos wool.  I think I may have to order myself a sweaters worth of this yarn.  It's amazingly soft and takes dye beautifully.  All of the skeins in this post were pre-mordanted with alum.

Left to Right: Onion skins, madder root, Hopi black dye sunflowers, coreopsis tinctoria, madder root