will it melt my plastic compost maker
No, no compost should ever become that hot.
https://www.gardeningknowhow.com/composting/manures/horse-manure-compost.htm
Is there any benefit in soaking horse manure in a heshan bag in a plastic rubbish bin full of water , if so,how long should it soak? Using the water to water hanging baskets and pots etc. thanking you
Here is a link with information on how to make and use manure tea.
https://www.gardeningknowhow.com/composting/manures/manure-tea.htm
https://www.gardeningknowhow.com/composting/manures/horse-manure-compost.htm
I have just put in a boarder bed in a wall gardened area. It mostly consists of aged horse manure. I am afraid that it isn't enough do I need to add soil. I have being mixing in soil in the hole that the plant is going into. I hope that I will get flower and not all leaves what else can I add to have a balanced bed.
You can't use mostly aged horse manure. You need a higher ratio of soil to horse manure. Perhaps you can remove some and use it elsewhere, and augment the current bed with soil.
Is cow manure safe to use on all plants and flowers
Properly composted, yes it's a great organic amendment.
https://www.gardeningknowhow.com/composting/manures/cow-manure-compost.htm
Is it ok to keep covered between turning with a loader?
That will be fine, although, you may want to add dolomitic lime, along with eggshells, and any other organic matter that you can find. Adding mycorrhizae to the compost will make it able to be used much faster. Here is a link that will help: https://www.gardeningknowhow.com/composting/
It appears as if cow manure was too strong for one of my shrubs. It appears to be dying. I have attempted to remove most of the manure, and have been watering ++. Is there anything else I can do?
What you are doing is correct. Here is more about this problem, known as fertilizer burn (but it applies to manure as well):
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/what-is-fertilizer-burn.htm
Manure should be "cured" or composted before applying to plants in order to reduce the risk of fertilizer burn and prevent the spread of plant diseases or weeds:
http://extension.oregonstate.edu/gardening/turn-manure-compost-your-garden
Hi I have a pile of horse manure in the garden and for the past three weeks turned it [twice] and covered it with black plastic also made a few holes [3] for aeration The horse manure is still quite wet and I have not added any water to the pile I feel I have done everything I can to get the process moving but to no avail My question is p[ease ? What else can I do, should I add lime in a few weeks time? Thanks for any help Ro
These sites have some information that may help you. They recommend adding other ingredients to the pile, like bedding material, wood chips, or plant material to aid the composting process.
http://www.extension.umn.edu/agriculture/horse/care/horse-manure/
http://esc.rutgers.edu/fact_sheet/best-management-practices-for-horse-manure-composting-on-small-farms/