01-28-2011 04:14 AM
White oak is an excellent choice for exterior applications. Visit any museum that features items that were use and kept out doors and you will see that a preponderance of these items were made of white oak and were left unfinished. White oak shingles split from billets were almost universally used on early structures as well as on doors and siding. Surviving examples can still be found today.
Any finish you apply, with the possible exception of an oil finish that you renew frequently, is going to be damaged by the hard use of garden bench (it is the finish that will fail, not the white oak). Besides, what can be more “natural” than no finish at all? That’s as natural as it gets and would fit perfectly in your environment, to say nothing of the fact that it would leave you free to concentrate on gardening…