Square Foot Gardening Forum

Hello Guest!
Welcome to the official Square Foot Gardening Forum.
There's lots to learn here by reading as a guest. However, if you become a member (it's free, ad free and spam-free) you'll have access to our large vermiculite databases, our seed exchange spreadsheets, Mel's Mix calculator, and many more members' pictures in the Gallery. Enjoy.


Search
 
 

Display results as :
 

 


Rechercher Advanced Search

Latest topics
» 2017 Burpee seeds are already on display at HD
by sanderson Today at 1:01 am

» Making Smoothies
by sanderson Today at 12:45 am

» Northern California & Coastal Valleys - What are you doing this month?
by Mellen Yesterday at 9:33 pm

» Holy snow Batman!
by AtlantaMarie Yesterday at 8:18 pm

» Senseless Banter...
by AtlantaMarie Yesterday at 3:37 pm

» Baker Creek's Seed Bank Store in Petaluma, CA
by trolleydriver Yesterday at 2:46 pm

» Food Dehydrators
by sanderson Yesterday at 1:21 pm

» Green Ice Leaf Lettuce
by MrBooker Yesterday at 4:46 am

» New England January 2017
by Scorpio Rising 1/19/2017, 10:11 pm

» Gardening Australia
by Scorpio Rising 1/19/2017, 10:05 pm

» New Forum Feature
by Scorpio Rising 1/19/2017, 9:56 pm

» Microgreens Gardening
by yolos 1/19/2017, 9:45 pm

» Hi from Acworth GA
by AtlantaMarie 1/19/2017, 9:40 pm

» N & C Midwest: January 2017!
by Scorpio Rising 1/19/2017, 6:14 pm

» California's Drought
by sanderson 1/19/2017, 5:46 pm

» CANADIAN REGION: What are you doing January 2017
by trolleydriver 1/19/2017, 10:54 am

» Winter Sowing vs. Winter Growing
by has55 1/19/2017, 3:32 am

» heirloom seed companies around a lot of the world
by ralitaco 1/18/2017, 10:58 pm

» What about ink on newspaper and cardboard for mulch?
by Scorpio Rising 1/18/2017, 9:23 pm

» Turan in the Western Mountains
by Turan 1/18/2017, 7:20 pm

» How's the Weather Where You're At?
by BeetlesPerSqFt 1/18/2017, 10:22 am

» Third Year SFG in Canada
by trolleydriver 1/18/2017, 9:23 am

» 2017 SFG Adventures in Hampstead, NC
by ralitaco 1/17/2017, 11:23 pm

» Daikon radishes?
by Scorpio Rising 1/17/2017, 9:49 pm

» Anyone want walking onions??
by Scorpio Rising 1/17/2017, 9:22 pm

» How much to plant?
by trolleydriver 1/17/2017, 2:48 pm

» January: What to plant in Northern California and Central Valley areas
by countrynaturals 1/17/2017, 2:22 pm

» Feedback for my 2017 garden plan
by sanderson 1/17/2017, 2:00 pm

» What are you eating from your garden today?
by countrynaturals 1/17/2017, 1:49 pm

» Show us your kitchen compost container
by CapeCoddess 1/17/2017, 1:23 pm

Google

Search SFG Forum

What are GDD's?

View previous topic View next topic Go down

What are GDD's?

Post  boffer on 4/17/2010, 9:52 am

This question came up in another thread.

GDD=Growing Degree Days

It's the amount of time a plant must spend above a certain temperature to reach maturation.It also applies to the life cycle duration of pests.

It's used by commercial farmers to determine when to apply pesticides so they are most efficient. Also, to determine when to prepare for harvest and transportation to market.

The 'amount of time from planting to harvest' that you read on seed packages is just a guestimate based on GDDs. If you have a cool summer, it takes more days to accumulate the hours. If you have a warmer than usual summer, it takes less.

Corn and tomatoes need 1400-1800 GD to reach maturity depending on strain. Dandelions take about 75. It's hard to find values for different crops.

The calculations are basic, based on high and low temps for the day. I found an auto web site here that charts an accumulative graph of GDDs throughout the year, based on the data from an automated weather station that's 10 miles from my house. It also contrasts the current data to an historical average.

One advantage to home gardeners if this information was easier to find, is when to start looking for squash bugs. By tracking GDDs, the experts know at what stage of development a bug is in, and when it is going to start causing damage. They can pinpoint their emergence to within a matter of days.

There's some google savvy members on the forum, maybe they can find more info geared toward homeowners.

boffer

Male Posts : 7392
Join date : 2010-02-26
Age : 63
Location : yelm, wa, usa

View user profile http://boffer.us/

Back to top Go down

Re: What are GDD's?

Post  martha on 4/17/2010, 3:47 pm

as soon as I figure out how to interpret this, the information on the referenced web-site will be really useful!

martha

Female Posts : 2188
Join date : 2010-03-03
Age : 59
Location : Acton, Massachusetts Zone 5b/6a

View user profile

Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum