Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: How long are the Cedar effective? one year or two year?
Document: Very effective to control the moth population in my closet - although i've never seen one - they must be there since I've seen the holes.
In New Orleans we have an annual flying termite infestation every spring. I live in a converted warehouse that has all of the crannies and nooks you'd expect in a 100+ year old building, so bugs can find their way in pretty easily. I'm reluctant to use insectiside around my dog and cat, so I put two of these cedar hang-ups on each window frame (in the kitchen, living room, bedroom, bathrooms, et al.) and it could not have worked better.
I thoroughly expected the them to smell like cedar but they only do if you put your nose right on them. They appear to be like a year old when you open the package! Loved the concept and that's why I ordered them.
I got these a year ago on amazon and they still smell like cedar! I like that they have a hanger on them so I can put them in the closet with my coats and other garments that I don't wear all the time.
Effective, if a tad weak. I gave them a good sanding and then applied some cedar oil to amplify the effect. Recommend this product in combination with the Giles and Kendall Cedar oil.
it did not have a cedar smell very long. nice idea, but not what i expected. other cedar i have had keeps the cedar smell.
These are fine for a short period of time but they don't seem to hold the cedar aroma long enough
These are great out of the box but the cedar smell - the only thing that makes them work - did not last long at all. I bought some CedarFresh spray to rejuvenate them, and that worked well, but it will require frequent upkeep. That is probably true with any cedar product. These are handy enough that I would buy them again.
i have a bad moth problem at home. In order to prevent them from eating away my sweaters and wool, i bought these planks to hang in the coat and walk-in closet.there are 18 of them and each about 6 inches long. there's a faint cedar smell but not overwhelming.i hope they work and will update this review after some time has passed.
Found I had a moth problem when 5 of my wool sweaters I hadn't worn for a year were eaten away. Didn't want to go with moth balls -- who can stand the smell. Heard that cedar was an alternative so I tried different cedar products -- square blocks, round ones with holes to put on hangers and then these. These seem to me to be the best solution for my sweaters and jackets.
Answer: I think it can last up to two years.  If you don't smell the cedar, you can sandpaper it so it will release again the smell.