My Lacinto Kale leaves have taken on a purple hue. Based on my research, it sounds like it could be a phosphorus deficiency. Does anyone have any thoughts on that? I attached pictures to help me diagnose this. I have curly kale in the same raised bed, it's leaves are much lighter green than I am used to - almost yellowish green (not sure if that helps narrow down the cause).

I used a new compost in this raised bed and I have not been a fan at all so far, I am considering a soil test or just pulling everything out of the raised bed and starting over.

Actually, for brassicas, many nutrient deficiencies can cause purple leaves. I'd be looking at magnesium or nitrogen actually. Purple leaves point to a phosphorous deficiency in non-brassicas. Also high pH can do it. Is this a bed that once had well-performing plants? Certainly a soil test is in order. Very light green leaves is often a nitrogen deficiency.

Thanks for your reply, @Doug! Very helpful.

This is a brand new bed, I recently moved and I could only (easily) get ahold of mushroom compost in my area which .. I feel has posed several issues already (also have been unable to direct sow beet and carrots in this bed).

I have always read how kale is not a fussy vegetable and I have grown it successfully for several years without much thought so I was very surprised to see it struggling so much. I have never been to the point where I have done a soil test .. I think I've been so lucky in the past with the compost I used to buy. So this is a learning curve.

For now, I've purchased some water soluble organic fertilizer (3-1-2) and I'm hoping that will help. Thoughts? I've also never had to use fertilizer in the past!

For now, sure, just dump on some broad spectrum fertilizer. But GET A TEST. Otherwise, you're just slathering on fertilizer that your soil may not need. Any new bed needs a soil test. Not sure where you are, but in much of the country, basic soil tests are done inexpensively by ag extension services. Don't do a DIY test. Those are frequently wrong.

Thanks so much for your input! I will look into what soil tests I have available to me in my area!

Ah, I didn't notice that you were in Tennessee. That's easy.
https://extension.tennessee.ed...
The el basic "nutrient test" is all you need. That will tell you what you're up against.

WOW! That's so awesome. I really appreciate the help and direction.

I definitely had it easy at my previous home, lots of learning is on the horizon here and you helped a lot. Thanks again.

If you have good gardeners as a neighbors, ask them. Your native soil is the same as theirs, so their nutrient problems will be the same as yours. But get a test .... (and share it with them)