In relation to the wood portion of the questions: That is such a nice planter, I'd also suggest you use it as a holder of containers. Notice the description says "holds pots up to 17 inches in diameter". Look real close at the slats on the sides, are they fitted pretty tight without any light showing between them? They probably are, which is good. The outside finish should be fine -- even if you decide to put soil directly inside it. The manufacturer leaves the inside unfinished because many people don't want to put anything on the inside of the wood when they place soil in it -- for fear of the toxicity. Cedar wood is right up there with good anti-rot features, even if you do not coat it. It will not last as long if you don't, but depending on where you live the years of elements may long damage the outside of the container (functionally and aesthetically) before an uncoated inside is ruined. Here in central CA this happens all the time. I've used a rubber or asphalt coating product that is used as a prune sealer. You can still find it in the big box stores as an aerosol spray either called Pruning Sealer or "Wound healer" or the like.. Actually, I just searched google and the topmost item returns this: Asphalt based sealer Which is the first time I've seen this, but it says "Can also be used to waterproof pots and tubs." Good luck, I have no affiliation with the above link provided so I cannot make any recommended to the vendor or the product.

Nice list, thanks! I have a dog, so the indoor plants I have are nontoxic: an african violet, a nontoxic fern, culinary herbs in hubby's Aerogarden, and a goldfish plant (which I love!! It is so cool looking.) Used to have a Persian violet which was fabulous and fragrant-- smelled great for about 2 months, but it eventually finished flowering, sickened and died. It was replaced by the goldfish plant.

I've read of a tungston oil, don't think I got the name right because when I searched it, it came up as the metal tungston. It was used regularly on untreated spinning wheels, will keep searching for the right name, but I'm sure that is it. There is also something called Teak Oil. I posted the url below. Also, don't think it's very organic, but I read about people building pole buildings and preserving their wood with kerosene. Surely kerosene can't be good for organic, but it's a thought. I hope that helps. Here is a link that might be useful: Teak oil

You might try corn gluten meal, as a grass killer. Lay it early as a pre-emergent, and reapply if you get sprouts. Not supposed to be poison for animals or birds, since it is almost regular corn meal. Garden sounds interesting, lots of fun for the cats. Geraniums might be of interest, not poison. They come in many sizes of tiny to large. Huge selection in flower colors, scented leaves and leaf shapes. Apple, rose, lemon, orange are scents that I have smelled. Put them where you will brush against them to release the scent. Bloom almost all the time in full sun. Pergoliam is the Latin, I think, which they might be listed under. They were real popular in Colonial times for scented leaves used in potpourri, flavoring food. Mine are floral, but the cat here does enjoy biting the leaves at times, sitting in front of the french doors in the sun. She also likes the Rosemary plant topiary! Nasturtiams are edible though not my favorite flower on food. Kind of a peppery taste when we ate them in a salad. Flowers are pretty, bright colors, like the sun. Martha Stewart sold seeds for a climbing variety, but mine missed the fence, just crawled around. Foliage is cute too, round leaves. Chrysanthemums are edible, very popular in Asian food. Japanese or Chinese, can't remember. They sprinkle the petals in soup, salads. Should be OK for a cat to chew on. Many shapes, heights, colors to choose from. They flower better with pinching tips back until 4th of July. You get more blooms on sturdy, shorter stems. They are perennials, can return each spring. Mine tend to be shorter lived, but other folks plants live for long times. Two of the flowers I named are annuals. Geraniums can be saved as plants over winter, dry in the dark basement or potted in front of windows over winter. Nasturtiams are available by seed in spring or you might be able to save seeds from this years plants.