Answer: This could mean several things. First, it could be that the soil is still just too cold for them, thus inhibiting their root growth and take-up of nutrients. It might also mean that there is an imbalance where the pH is overly acidic which would interfere with the plant absorbing nutrients, or that there is a lack of phosphorus in the soil. Since they are already planted, I would suggest a foliar feed with a complete fertilizer and see if that helps. Look for one with an analysis of 10-10-10 or similar and follow the label instructions. This should help within a week or two if it is due to a lack of nutrients in the soil. Since this is the time of year when the soil also is warming up, that possible cause should also be taken care of. You might also want to run some basic soil tests to check the pH and fertility. Your local county extension and/or professionally trained nursery staff should be able to help you with the testing and interpreting the results. One other possibility is that they have not rooted out into the soil beyond the soil that was originally with their roots. If they seem stunted as well as turning purple, you might try gently lifting one or two to check and see how the roots are doing. If they are still in the original soil and have not spread, you can try to tease them loose and direct them outward and replant. Good luck with your geraniums.
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