Hi, Thank you for taking the time to submit your feedback to us, I'm sorry to hear about this inconvenience. We try our best to make sure we inform our customers about the necessity of sealing the Bamboo right after fencing installation. We try to bring awareness to this matter by stating on the product page under product description "Treatment: fencing is not treated, always apply a good quality; oil-based UV-resistant wood sealant using a brush for best application" as well as sending a "how to treat your bamboo fence" and a disclaimer pamphlet inside of every box we ship out. I apologize if you didn't receive your pamphlet, I will bring this issue to my packing team attention. If you have any suggestion to help us improve the communication about this matter, please feel free to email it to us, we are always looking to ways to refine our products and service.
Please keep in mind that Bamboo is a natural product and mold and mildew may grow when exposed to weather. A good oil-based sealant can help protect the Bamboo fence against UV rays, rain, mold, and mildew. We recommend TWP 300 series. Please don't hesitate to contact us with further questions or concerns, I will be glad to assist you.