Question
what chances does my large purple plum tree have of surviving after tropical storm toppled it over to the ground. Only about 1/4 of roots were exposed. I immediately called landscaper> was told to cover it with soil and gently water.Plans to straighten out tree and secure roots with more soil will take place on Wed. What are the chances my tree will live. IT is the most loved tree in my back yard.
Thank you. ANy suggestions would be appreciated.

Answer
The smaller the tree the better chance that the tree will be ok. The problem may not be that the root system can not supply water and food to the tree but is there enough root system to support the tree during future wind storms. Saying that I think it is worth the effort to try. It will take several years for the root system to grow back on the damaged side.

For trees smaller than 8 feet, the chances of  uprighting the tree and saving  it are good.  However, it will probably only be successful if one‑third to one‑half of the roots are still in the soil and not exposed.... and if the roots which are exposed are fairly compact and undisturbed.  

The process of 搖prighting?the tree may require some type of lift equipment to pull the tree upright.  Before pulling it upright, you should remove some of the soil beneath the exposed root mass to allow the root mass to be situated at soil grade level.  Once you have the tree back in place, fill in the soil around the roots as needed, being sure to keep the tree at the same soil level as it had been before it blew over.  Water the tree thoroughly to get rid of air pockets and settle the soil around the roots.

Since the tree has lost a portion of its anchoring roots when it blew over, you will need to give it some support in the form of staking.  Tie the trunk to the stakes at the lowest height which stabilizes the tree in an acceptable upright position. make sure the 'ties" are padded so they will not cut into the trunk. The stakes should be removed when the tree can stand by itself.  Check the tree every year to make sure it's still stable. This may take several years. If it's not, removal may be needed to maintain safe conditions.