Editor's Picks

Michel Gandoger in an albumen silver print dated 18 March 1876, dedicated on the reverse to Roberto de Visiani - Image: PHAIDRA University of Padova Attribution-NonCommercial-ShareAlike 4.0 International

Gandoger the Memorious

While working on a list of synonyms of European White...

Roderick Cameron | Aug 24, 2026

Cover of Select Native Asian Oaks Gap Analysis

Conservation Gap Analysis of Select Native Asian Oaks

Report led by The Morton Arboretum will help prioritize oak...

Website Editor | Aug 06, 2026

Early Fruiting Quercus robur in Slovakia

Motivation I live in the village of Dolné Dubové...

Jozef Čapkovič | Jul 20, 2026

Plant Focus

Species Spotlight: Quercus afares Pomel

The only oak species endemic to Africa is rare in cultivation. It shouldn't be.

American Plant Hardiness Map 2012

By Charles Snyers ... | September 16, 2012

In January 2012, the USDA Agricultural Research Service released a new edition of the American Plant Hardiness Map. The previous edition was released in 1990. Two new zones 12 and 13 have been added to this 2012 edition. The zones are based on 1976-2055 weather data, that is 30 years of data. The 1990 edition was based on 13 years of data. See the What's new section of the USDA ARS Web site for details here.

For the first time, the map is available as an interactive GIS-based map.