American Hydrotech, a recognized leader in the vegetative roofing market, today announced the availability of the Fourth Edition of the company’s widely acclaimed Garden Roof® Planning Guide. For the last five years, updated print, online and app version of the complimentary resource have transformed more than 22 years of vegetative roof experience into an educational tool and resource for architects, facility management, building owners, installers and contractors on the latest technology, applications and benefits of vegetative roofs.