Very hardy plant every year, requires trimming but it will not produce any flowers.
Here are some articles that will help you that outline the reasons why wisterias do not flower and how to remedy them:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-blooming-problems.htm
https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-buds-dont-open.htm
My wisteria has struggled to flower this year and on looking closer, it has some sort of disease. The branches have like clusters stuck to them similar looking to like a tiny beetle or like barnacles. Not sure if I can get rid of it and what to use.
It sounds like your wisteria might have a scale infestation. Scale would look like "barnacles". For more information on scale and a course of treatment, please visit the following link:
https://www.gardeningknowhow.com/plant-problems/pests/insects/control-plant-scale.htm
My wisteria vine is 6 or 7 yrs old and has never had a problem with leafing out before. However, this year it developed buds that never leafed out. I assume the vine may be dead, but curiously there is a healthy green shoot (about 4 ft. long) coming up from the trunk. It doesn't seem to be sprouting from the graft, so I'm wondering if the root may still be alive. If so, would it do any good to prune back the branches that didn't leaf out, let the new shoot continue to grow and see if it recovers next year? Thanks for your advice.
Before pursuing anything, I would recommend that you review the content in the article below which discusses why wisterias do not leaf out. This article will help you determine whether or not your wisteria vine is still alive. I tend to think that due to the presence of buds that it's just taking its time to leaf out after the cold spring we just had. If in fact it's not alive, then you will know for sure that pruning it as you are proposing is the right choice.
https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-no-leaves.htm
My wisteria vine has vines running across the lawn that have rooted. Where should I cut them and how should I plant the vine? Some of the vines are 10-12 feet long with very long roots. Should I bury the whole length or cut it into sections?
It sounds as though your wisteria needs to be pruned. From what you described, it sounds like you have some unruly shoots (which need to be removed). I am assuming that these divergent vines are unwanted as they go astray from the rest of your wisteria plant that you have trained on your arbor or pergola.
Here are some articles that will help you with this situation:
Controlling wisteria:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/controlling-or-getting-rid-of-wisteria.htm
Pruning wisteria:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/pruning-wisteria.htm
For more information on the care of wisteria, please visit the following link:
https://www.gardeningknowhow.com/ornamental/vines/wisteria/growing-wisteria-proper-wisteria-vine-care.htm
I had a thriving 10 year old wisteria which I planted some new plants under late in the spring. I put them in with Miracle Gro compost and some compost from our home composter. A few weeks later my wisteria lost all its blossoms and looked ill. Checked soil pH and found it to be 5.5, so I added some lime to raise it and then added some John Innes no 3 compost. Wisteria still struggling with stunted leaves. Any ideas what I can do to help it?
The Wisteria most likely received to much fertilizer and Nitrogen.
Here is a link to refresh you on the care.
Our Wisteria, which had lovely flowers this year (it is about 10 years old), has literally just died. The whole tree is brown and brittle. It seemed to happen over night. Is there anything that can be done?
It sounds like it may have been hit by overspray from someone spraying weedkiller. Were you or a neighbor spraying anything like that recently? The wind may have carried it to the plant. If the leaves died, there is still a chance that the stems have survived. If only the leaves died, it will grow back. This article will help you determine if it is truly dead or just defoliated: https://www.gardeningknowhow.com/plant-problems/environmental/how-to-tell-if-a-plant-is-dead-and-how-to-recover-an-almost-dead-plant.htm
I've noticed odd brown nodules on an otherwise healthy wisteria in full bloom. The nodules are covering the stem and pick off easily. Inside they are dry and powdery. Should I be worried about this? The wisteria grows well every year and is approx 16 years old.
It appears to be spores of some kind. Scale insects would leave a sticky residue.
Watch for that.
You could treat with Neem Oil.
Here are a couple of links.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/ornamental/vines/wisteria/wisteria-diseases.htm