Horticultural anxiety

Having a bit of a nightmare this evening. I had a large batch of seeds ( very expensive for use in a public landscape project) and left them in my car all day with the doors and windows closed. It was British wildflowers and grass mixes ( to the value of about 800 US dollars). It was a warm sunny day with temperatures reaching about 16 degrees C ( 61 farenheit) and I'm guessing in the sun that temperature in the car got up at least twice as high.
I'm very worried that the seeds may have become damaged. Have sown some as a test but will have to wait ages. Have alo tried floating them and most did float ( although I don't think that is a true indicator of damage)
Has anyone any experience of this?. Any advice/ words of wisdom?
Apart from the cost I'm concerned about taking time sowing them, if they turn out to have lost viability. Also, the delay if it turns out I have to buy more.

Seeds float, or don't, as a function of their surface area versus weight... not necessarily anything to do with viability, although without even knowing the species, it would be impossible to say if they should or shouldn't float. At any rate, a few hours at moderate temperature (30 deg C?) shouldn't change anything. The seeds probably experienced greater temperature swings in-situ prior to being harvested. Again, knowing whether a delay in sowing them would be detrimental or not depends entirely on the species, and whether the seeds are ephemeral or are killed by dry storage or become less viable with time. (There are also many species that require dry storage prior to germination in order for germination inhibitors to break down - in other words, viability increases with time.) Anyway, if you have access to Deno's works, you may be able to look up the species and find out its seed behavior. Deno also wrote about seed storage, which may be helpful if you cannot sow for some time.

At any rate, I wouldn't see that incident, on the face of it, as anything to worry about... on the other hand, I've never spent $800 on one batch of seeds, either, so I can certainly see your reason for concern.

This message was edited Apr 10, 2010 8:20 PM

Thanks for that excellent information Altagardener. I've calmed down a bit now but got in a bit of a panic when I relaised I'd forgotten to unload them from the car. I think it probably got to more like 35 degrees judging by the temperature indicator in my wife's car on Friday ( similar weather). Anyway, I'm going to get them sown a soon as possible and hope for the best.

Mr C. Here is some info for you from the Annals of Botany discussing heat/germination viability that you may find informative.

http://aob.oxfordjournals.org/cgi/content/abstract/45/1/13

Moon , where do you find all that info ? So many of our members post threads to provide all these answers, and I don't have a clue to know where they get it . digger

Hiya Digger. Everything comes from Google....I just enter the topic (for here it was Heat extreme effects on seeds) and then sort of browse through the results to see which link might have the best info or closest answer....sort of like the yellow pages....I let my fingers do the walking GRIN

Sometimes I find I have to reword my search a couple times...computers can be so picky....grin but usually, if the answer is out there Google can find it. It just becomes a matter of asking the right question.

Are y'all getting settled back in now?

Yeah , somewhat settled in . Did yard work yesterday . Dh conked out on me.
This morning , I'm getting my DG fix .
What I need to do is straighten up and unpack some more . DG first, been away so long . Google ? Duh. digger

I know you are glad to be home...and I am glad you are back on DG. Good to see you.

Thanks for looking out for that Moonhowl. There is some amasing scientific info out there. Have to really get my brain in gear to understand it though.
One thing thats made me feel a bit better about this episode is that I, as soon as I realised what I'd done, I sprinkled some seeds on damp paper kitchen towel, and just now (approx 48 hours later ) I can see the little sprouts of germination in a couple of the species. There are several species there though and they will of course vary in their thermal death point, but so far so good

I hope they do well. Sometimes when searching for things I get into areas that were meant only for those who eat, sleep and dream botany.....grin. I hope the article was not overly taxing or too pedantic. Oh, by the bye "and are ye daft man?" Grin

'Are ye daft Man?' sounds like it should be said in some regional British accent. Not sure which one but yes Jean; feel pretty daft when I read those science papers

Probably a bit o'Scots Mr C. or Scotch if the paper is too dry....grin

I'll go for the Scotch, especially with all this horticultural anxiety. To think I got into gardening because of the peace and therapeutic value it would bring. Having said that, there are 3 differenet species happily sprouting on my paper towel now so I'm feeling quite a bit less anxious

To avoid horticultural anxiety, it is good to get someone to help dig up your garden for you!

Thanks Metrosideros. Those guys are lovely and really do look like they could do a useful job in the garden.
This is my helper but he doesn't dig; just follows me around and treads on all the plants. But he does a good job of reducing anxiety

This is my garden helper, but all she does is eat my plants and chew on my ficus hedges.

Oh Dear! What have you stared Metrosidoros?

No offense Grantman; but your helper appears to be completely mad

Always good to take a little paws from our daily routines!

Wow. That one looks like the boss to me. Does that make you the Assistant Head Gardener?

That was the security guard.

Here's the Boss!

Oh Yeah! I see what you mean. You wouldn't argue with those eyes would you.