Out door yukkas, very tall and thick Trunks,near a metal fence. Will they Damage the fence?
Very, potentially, depending on the proximity to the fence. This article will help you to remove them:
I have had this plant since it was tiny and it has been healthy and flowered every year with many bloom clusters which the bees love. This year the Bark is falling off all over the trunk as seen in photos. There is no other obvious sign of disease or insect. The bark seems to be lifting off then dropping randomly all around the tree trunk which is about 15 - 20 feet tall.
It might Have Armillaria or other similar root rots! Treating with a fungicide, right away, will be the best option.
I have recently had 4 yukkas removed and the stumps ground to chips. Is it OK to leave these in the soil for drainage? They were poisoned by drilling holes in the centre 4 months ago, so would there be any residual poison still in the chips? I do intend to add compost and manure to the soil as well before planting anything else. Thank you
It depends on what you used, but some stay in the soil for around 6-8 months. As long as you leave it for that time, then add organic material, it should be fine.
These articles will help you to keep your soil tested:
What should I use to fertilize my outdoor Yucca plants? How often and when is the best time of the year to do it?
Because this is a desert species, they do not require much fertilization. If this is grown in a decent quality soil that is not compacted, then fertilization will only be necessary when a soil test reveals nutrient content to be low. You will likely never see this, but if you do, an all purpose at half strength will do.