En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - How are full sun, part sun, etc, defined?

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.

Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Tuesday - April 08, 2014

From: Midland, TX
Region: Southwest
Topic: General Botany
Title: How are full sun, part sun, etc, defined?
Answered by: Joe Marcus

QUESTION:

Hello, I have a question about sun requirements. Does saying something needs "full sun" mean a particular number of hours? Does it mean 6 or more hours / day? 8 or more? Is there an agreed upon numeric value for full sun, part sun, and shade? Given that we can fairly accurately model sun conditions now on a site, just curious where the line is drawn. Thanks so much. Love your work.

ANSWER:

There are specific definitions for full sun, part sun, part shade and full shade, but with these definitions there is a healthy dose of art that's thrown in with the science of it.  We define full sun as an area that receives more than six hours of direct sunlight each day.  Part sun is defined as receiving four to six hours of sun each day, while part shade areas get two to four hours of sun daily and full shade areas are defined as receiving fewer than two hours of direct sunlight each day.  However, the mitigating circumstances can be a bit tricky.  For example, afternoon sun tends to be more intense than morning sun.  Sometimes, reflected sunlight can play a significant role in light quality and intensity.  Finally, geography also affects light intensity with desert areas and high-elevation regions having generally more intense sunlight than other places.

 

More General Botany Questions

Plant for science experiment from Kentfield CA
November 10, 2009 - What is a fast growing plant I should use for a science experiment?
view the full question and answer

Night-flowering plant that blooms every five years
September 20, 2008 - What plant flowers every five years at night?
view the full question and answer

Do bees visit cedar trees and other conifers for pollen?
November 30, 2013 - I was wondering if honey bees or native bees visit cedar trees for pollen? and what about other conifers?
view the full question and answer

Smarty Plants on aceae
March 21, 2005 - How is the family suffix "-aceae", as in Asteraceae, pronounced? I find disagreeing claims in my searches- "ay-see-ee" and "ay-see-ay" seem to be the most common, but I've also seen just "ay-...
view the full question and answer

Fragrant Texas wildflowers
April 10, 2013 - Hello! I am researching native Texas wildflowers and I am looking specifically for flowers with a pleasing aroma. Is there anyone who has made a list that includes how the flowers smell? Do you kno...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center