protecting outdoor vase

I have repaired an outdoor vase (that had been vandalized), using mostly waterproof expoxies (Apoxie.com products).  I’d like to return this piece of artwork to its original location outdoors, in upstate NY.  My greatest concern is to weather-proof it against growth of algae, moss, mildews, etc. 
As you can see by the attached pics, the surface of the vase (which stands about five feet tall) is varied.  Some of it appears porous, some of it gives indication that the clay (I’m assuming) has been fired in a kiln, and some of it appears to have been treated with a “wash” (my layman’s term for what looks like what it was treated with). 
You’ll notice the chocolate brown-colored “scar” in the middle of the vase – this is the Apoxie product before it’s sanded smooth.  Then it turns the gray color you see at the base of the neck near the top- that’s where the most damage occurred.  All of the multi-colored, “mottled” parts – the light browns and various green hues – were present when I purchased the property the vase was on (2013).  I suspect this appearance occurred either during completion or as a product of outdoor weathering.

Ideally, I’d like to apply some type of “wash” to the entire exterior of the vase that would mimic the present mottling or at least render all of it of a somewhat uniform but random appearance – not necessarily a fully opaque coating.  My number one priority is to weatherproof the vase enough that it can be returned to the outdoors and not suffer the ill effects from exposure to the elements. 
Thoughts on how to proceed? Thank you.