Allotments 4 All

I have always believed that Lettuce is a coool germinator. I try to give it separate treatment.

Confused!  http://tomclothier.hort.net/page11.html

It appears that the optimum temperature for germination is 77 degrees fahrenheit, which is roughly 25 degrees Celsius? As a maybe one day scientist :-\, even though I like the table shown, I wouldn't be so happy about not being able to examine the source data on which the table is based. It says that 'The above data was taken from a report published in the mid-1980's.  Author, affiliation, and publisher are not known.'

Or, maybe it's a mad mutant American lettuce?

Niamh

Interesting table.

It does add in a footnote that just because something germinates quickly in hot temperatures doesn't mean that it should be grown at that temperature - there is a comment about lettuces not forming heads when it gets hot.

Lettuce seed is sensitive to both red and far infra-red light. It takes a red light as 'go' for germination and infra-red as 'stop'. So it may be that it's the bright sunlight which stops lettuce from germinating well in summer, rather than the temperatures?

Very interesting!  My OH does the majority of germination of his seeds on some damp kitchen roll on a plate with a freezer bag enclosing and they are put in the airing cupboard and all his seeds have germinated apart from cucumbers, but they were old seed.  I have been doing mine in a seed tray with a piece of black plastic bin liner over and all of mine have come up. I even did 3 types of lettuce this way and they came up quickly. They are all on our dining room table against the window. However,  I started off some busy lizzies in a propagator, as the seed packet advised and so far not a thing.  busy_lizzie

you know i have a table of the exact same figures in one of my books (square foot gardening) and it says that the information is "adapted from Harrington, J.F., Agricultural extention Leaflet, 1954" 

the accompanying paragraph goes on to say, "...although the spring or cool-weather vegetables such as lettuce and spinach can sprout at cooler temperatures, they take a long time to do so and actually do much better at higher temperatures. ...Cool-weather crops need to mature in the cooler part of the year, but they prefer warm temperatures as they germinate and begin to grow.  This is why a crop of cool-eather vegetables grows better and produces more if planted in the fall than in spring."

So I've been wasting all these years!!

Ask & ye shall be told. So onto the heat they go!!