Following is the recipe for the preservative. Disclaimer: I make no gaurantee whatsoever that this preservative will actually work or make your Christmas tree fresher or last longer or more resistant to fire. I just suggest that you try it for yourself and see if it works. If it doesn't, well, sorry. It did for us.
2 C karo syrupThere you go. Hopefully it will work for you as well as it has for us.
2 oz liquid bleach
2 pinches epsom salt
1/2 tsp borax
2 gal hot water
Mix together in bucket, make fresh cut on tree trunk, soak tree
overnight. Use this solution to refill tree stand as needed.