Needle plucking black pine

I have 25 plus year old black pine. I am in the process of candling and have a question about which needles can or should be plucked. Last year I was not able to do a thorough candling and needle plucking, so I have ended up with two sets of long needles. The picture shows after candling and plucking the first set. Can and should I pluck the set behind the set I plucked or leave until tree is more fully developed with smaller needles?I have also included a pic of the whole tree.

Okay, here it is.

In general, most or all of the old needles can be plucked as well as some of the new needles in strong areas. The biggest exceptions to this are when there aren’t many needles on the tree in total or if you are considering cutting back into the area where old needles are growing to stimulate new branches (see for details about this approach).

If you upload a photo of the whole tree we might have a better idea about how many needles to keep or pluck.

Here is pic of whole tree. It is pretty dense, but has fairly large needles.

Bottom half has been candled and needles removed yesterday.

Thanks Nancy. I’d likely remove all of the needles that grew in 2016 or earlier and only keep some of the 2017 needles where I’d want back buds.

As for how many needles to pull, I’d likely pull about half of the needles in strong areas and fewer in weaker areas. Because the foliage is not yet dense, I’d leave more needles than normal, maybe 12-14 per branch, though it’s hard to tell exactly from photos.

What I’d want to avoid is over-plucking as removing too many needles is stressful for the tree.