My barberry shrubs are not thriving. They have very tiny leaves and are thin and not filling in as healthy barberry shrubs should.
Have you had the excess heat this summer, as reported in many areas out west?
If your temperatures have been above normal, this certainly will effect and stress your shrubs.
Make sure the soil is receiving enough moisture. Mulching with 3 to 4 inches of hardwood mulch can help keep roots cool and moist.
Planting in an area that has morning sun and afternoon shade is also recommended in warmer climates.
This article will help with care requirements.
https://www.gardeningknowhow.com/ornamental/shrubs/barberry/barberry-shrub-care-tips.htm
When pruning the dead branches I found that quite a few branches have a very gold yellow within the bark. Also, when I dug this bush up thinking about replanting, I found many roots were also yellowish. Is this plant dead or possibly have a disease??
Yes, this is definitely a barberry thing! It is common for barberry and their close cousin, the mohonia to Have this yellow inside the stem. This chemical is called berberine, and is a defense mechanism from predators. This coloration is normal and not an issue to be concerned with.
As far as the dead branches... It is wise to remove them, so an infection doesn't set in. Here is another link that will help: https://www.arboretumfoundation.org/about-us/publications/bulletin/bulletin-archive/hidden-gold-internal-coloration/
And can they be grown in plant buckets?
Fall is a great time to plant.
https://www.gardeningknowhow.com/ornamental/shrubs/barberry/barberry-shrub-care-tips.htm
I need to prune Burberry bushes that are overgrown, to tall for hedging. Fall and winter is ok, but how much do you cut back?
These are invasive in most areas. They won't be particular about how much that you cut back. Just cut the the height and shape that you want, and it will grow back from there.
This article will give you more information on their care: https://www.gardeningknowhow.com/ornamental/shrubs/barberry/barberry-shrub-care-tips.htm
The two above plants are exotic invasives that easily escape cultivation and are crowding out important native plants that provide food and shelter for native bird species and wildlife as well as larval hosts for critical native butterflies and pollinators. If you are interested in educating the public, you might either remove these plants or make special note of the problems associated with these particular species. Thank you Diane Cooke
This is very true in some areas. This is also true of any plant species, as any species has the potential to become invasive given the right conditions, and it would seem a bit excessive to post a warning on every plant posted.
There are places where plants that are invasive are quite docile, when they are far enough from their natural habitat to thrive. As always, it is wise to make sure that any plant that you intend to put into the area is not invasive before planting, as a responsible gardener.
It is turning into spring here in west Texas and many trees are starting to green up and become very colorful. I planted 4 barberry shrubs in large planters out in front of our house late spring last year. They are not showing any signs of getting new leaves or awakening for spring. Did I do something wrong? Should I cut them down some and see if they return? How do I know if they are gone or still alive?
The first thing to do would be to break the tip of a stem. If it is dry and brittle, keep going down until you find a flexible, or green portion. This will mean that it is still alive, and now would be the time to prune any dead growth off.
There is a picture of a Barberry bush on the above page. What type or species is it?