I do know youll have to renew the finish. M\y sons home is cedar. It was built 9 years ago we did it twice so far. The sun fades it. Its not dark he basically wanted to get something on it because if you dont it wil turn an ugly black moldy looking color. Now our huge barn we built we stained with a transluicent gray. It also fades. Our 1700 barn is also done in gray.so you will have to do it from time to time. We had a party we had about 7 people it took us one day to do the whole house. Its a cape cod with the whole second floor in back one big dormer. Then when done we had a party.He served us cold drinks all day it was fun really.

You might check the eco-paint catalogs. Bioshield has lots of stuff and they have some wood stain / preservatives. You might also do an internet search for "natural wood preservatives". When we redid our hardwood floors naturally, we did find quite a few sources.

Here is a link that might be useful: Bioshield

This is treated with 50-50 diesel oil and tar...
After two three weeks its as dry as a telephone pole...
I love it and would do it again...

Thanks for the lovely picture, kbeitz.

Diesel oil and tar are non-toxic? Maybe compared to the arsenate-treated and worse, creosote-treated stuff. An oil-tar mix would be a good herbicide, similar in action to the old "carrot oil" used to kill roadside and railbed weeds, including some hard-to-kill perennials.

Cedar is naturally rot-resistant but weathers irregularly. Most treatments will darken the older wood. If you like the color already you might try a water-proofing treatment applied several times over the course of a week or so. You can also use boiled linseed oil thinned with perhaps paint thinner (is there a less toxic alternative?) and brushed or sprayed liberally. The surface will darken.

If you ever want to darken/"age" new redwood and some cedarwood, make a "paint" of baking soda and water and brush on for a darkened look. I do that on redwood benches and fencing for that instant weathered look. The dark colors fade with time to true aged ones.

I've had some degree of mildew growing in linseed oil base finishes. Depending on how sterilized the boiled oil is and other variables concern with humidity or rain, environmental what have you, To avoid this problem I pore in one quart of fresh motor oil to 5 gals. of whatever oil finish you are going to use.

Oh my goodness!!! We just discovered that the BEST way to clean cedar siding is with VINEGAR (white or apple cider)!!!!! Yep, VINEGAR!!! We have battled with mold the past 10 years and have tried everything on the market- and now to learn that good old vinegar works like a charm is like a miracle to us (to our backs and to our wallet)!!!! DO NOT POWERWASH and DO NOT USE BLEACH or oxygen crystal products like Oxiclean! Just mix vinegar and water, spray on, scrub very lightly (so that you don't take any stain off), and viola! WOW!!