The American Hosta Growers Association developed the following hosta clump size standard in 2012 to address a void in the industry for a broadly accepted standard. The final standard is not perfect, but it is simple and it addresses the needs of the overwhelming majority of the hosta growing public as well as most gardeners in general. While this standard is based on clump height, clump width is also addressed.

This standard addresses the simple fact that hostas do indeed grow larger in the North than in the South.  A size standard that addresses these regional differences is helpful in educating and managing gardeners’ expectations.

The AHGA clump size standard is not to be confused with the AHS size standard.  The AHS standard is based exclusively on leaf area and is used mainly to classify hosta leaves in a leaf show.

 

Hosta Clump Height

Size

North

South

Mini

up to 8″

up to 7″

Small

9-14″

8-11″

Medium

15-22″

12-18″

Large

23-29″

19-24″

Giant

30″ and above

25″ and above

 

Notes:

• The above size ranges reflect the fact that any specific hosta cultivar will generally grow a few inches taller in Northern climates as compared to Southern climates. The larger the hosta, the greater the spread between heights in the North and South.
• Sizes are based on average mature clump heights (generally 5+ years).
• Mature hosta width is generally about 2 to 2.5 times the mature height.
• Width-to-height ratios can vary significantly with upright hostas and with rhizomatous hostas.
• Above I-80 is the “North” – the best hosta growing area in North America. Below I-40 is the “South.” Along I-70 is the Middle Zone.

 

“North” = Above I-80

 

“South” = Below I-40