AusBonsai

4 of my small shimpaku have random spots of dead growth, i have about 10 others in the same spot receiving the same care without issue, would somebody be able to point me in the right direction with what could be wrong with them? The patches started about 2 weeks ago, they all still have lots of new growth with the random dead foliage you can see in the pictures.

We've had some posts recently showing junipers with scale and /or mites. You may need magnifying glass to see them - really small, on the leaves.
Here's the most recent showing fried egg scale insect viewtopic.php?f=131&t=26574&p=262676&hi ... le#p262661

Thanks neil, i will take a closer look today, couldn't see anything yesterday but didn't have a magnifying glass. If it is scale/mites, will they spread to nearby tree's?

If it is scale/mites, will they spread to nearby tree's?

Depends on the species of scale or mite and the species of trees. Many pests have specific hosts and don't bother other trees, some are more cosmopolitan and will feed on lots of hosts but if you have other junipers nearby I would check all and treat all if you have a pest problem.

There are a couple of other possibilities if you can't find any evidence of pests.