dead ends on juniper shrubs & pruning

Asked March 27, 2019, 3:32 PM EDT

1. The 25 yr old junipers on the west side of our house are greening up but the ends are showing yellow/light brown ends. This is not normal coloring of this shrubs. Is this from lack of water during the winter or from extremely low temperatures? What should we do? (I pruned the larger yellow ends before I took the photo. They were from 2 to 4 inches long and very obvious.)
2 Larger spreading junipers have overgrown the driveway edge. What is the best way to reshape & prune back to the desired size? Is March ok to do this work? Is it best to replace these larger junipers?
3. What is the correct way to prune? Where on the shrub? What time of the year?



Arapahoe County Colorado

3 Responses

Hello there,

1. With regards to the yellowing needles,it's certainly ok to trim off the yellow ends, but that you may not be finding the cause of the problem.

I doubt it's from lack of winter watering since we have had a good bit of moisture this winter. In fact, junipers will turn yellow from too much water. So, depending upon their location, this could be the problem.

It could be a couple of other things. You should dig around the shrub to see if any pests (ie. voles, rats. etc.) have been gnawing on some branches. Junipers branches often turn yellow before dying. Also take a look up close at some needles to see if you see any little bugs ( spider mites). If you find the spider mites, just hose off the shrubs. Spider mites hate water. It could also be juniper scale that infected the plant last year. Here's some information on juniper scale and what it looks like.
https://utahpests.usu.edu/ipm/ornamental-pest-guide/arthropods/scales/juniper-scale

2. You can prune Junipers any time it's above freezing. The best time is March/April before the new growth shoots out. Avoiding pruning back so far that only a woody stub remains. Nothing will grow back there. You'll need to decide if your Junipers are worth pruning or need to be replaced.

3. Here's some more information on pruning junipers. When you open the document, just scroll down to the juniper section. http://cmg.colostate.edu/Gardennotes/617.pdf

If you have any further questions, let me know.




Thank you for your reply. I'll examine closely but it appears to be juniper scale. We'll take a piece in a baggie to the local nursery for confirmation. We'll treat as recommended.

How far back can I prune the spreading junipers? Will the parts without needles below the tops take long to regenerate after we prune?

As long as there are green needles on the branch left, the needles will grow out. But whatever is cut back to the brown branches will not grow.

As far as the scale goes, you can prune out the infested parts. But again, don't prune back too far or nothing will grow back in its place. You'll need to pick up some insecticide also and treat the juniper according to the label.

Good luck.