Back to School - Germination Temperatures II

Last time I tried to analyse the connection between temperature and germination I got in a bit of a bind.

The following two links are the best way of summarising the facts.

First the Edinburgh climate:



http://www.rbge.org.uk/assets/files/science/Weather/2009%20in%20perspective.pdf

Note that the soil temperature is roughly midway between the daily maximum and daily minimum and fluctuates less. For outside sowing soil temperature is probably the best guide. With some crops (onions, leeks, brassicas) to give youself a head start it is advisable to start seeds off indoors and acclimatise them to the outdoor temperature after germination in a greenhouse before planting them out once the outdoor temperature has risen.

Secondly someone has kindly summarised the data on the first chart into a digestible form.

http://organicgarden.org.uk/?page_id=2120

All that is now required is to sort the data in order of ascendance of the minimum temperature in the optimum range.



Also I need to set up my 'greenhouse' and install the max/min thermometer I already have, and mabe buy a soil thermometer. Meantime, it continues to be unseasonably cold in Edinburgh. Researching this topic has kept me out of mischief.

As a footnote I have noticed that ALL the germination/temperature information on the internet appears to derive from the one American study (the one with the raw data given in the first picture of my previous post). There were a couple of glaring holes in that study where data is missing. Has no one tried to replicate this study?

I've discovered that the Council has decided to cane Edinburgh allotment holders by bumping up the rent by another £40 over the next 4 years (after doubling from £30 to £60 it in the last 5 years) My next post will try to address this local problem. Councils tend to follow each other. Is anyone else experiencing such a vicious and sustained hike in rents?

Nearly forgot the tune of the week: Money ~ Flying Lizards
Money spent: £24 (Impulse buy of 6 fencing posts)
Time spent: 1hr - fencing duties.

St Valentine's Day Brassica

I don't like adverising my failures, but seeing as I have bleated on about the pigeons you may as well see what I was talking about. And besided if Soilman can show you his manky compost heap...and yes, I just couldn't resist the pun.

Taking advantage of the lowered net the pigeons gave the cavelo nero a haircut:



When the snow weighed down the netting they stripped the curly kale:



Here's a plant they couldn't get at (just to remind me what we I'm missing)



And just to cheer me up here's this year's brassica patch. Last year's is to the right of the picture. I've dosed it with lime today. Note the sturdy posts between which I am going to stretch chicken wire. Its a narrower strip than last year and I will put in a few tall canes centrally, once I top it out with plastic netting, after planting out. Confucious said (something like) A wise man learns from his mistakes - and a genius learns from the mistakes of others.



Today's song: Lime Going To Be Your Numer One (Blondie's version of 'The Tide Is High')

Time spent this week: 2 hrs
Money spent: Nowt

Waiting for spring...

Allotment bloggers are looking for signs of spring, and for my part I've seen my first snowdrops of the year in the wild. I'm itching to get started. Prompted by other blogs I've already been panicked into buying seed potato far earlier than I intended. At least I got what I wanted. But now I see blogs where seeds are being popped into modules and I'm scurrying off to check whether I should be in full sowing mode yet. Let's be a bit scientific about this.

Here I must point out that I am a fan of outdoor sowing. My plot is several miles accross town and doesn't have an operational greenhouse. At home I do have an unheated mini greenhouse that amounts to a glorified transparent Wendyhouse. There isn't much windowsill space either. And given that I have to transport any homegrown seedlings, wherever possible I sow seeds straight into the soil at the plot.

I've got a god idea of the order of sowing (parsnip, broad bean etc)but how soon can I get started?

The key factors has got to be (a)the seeds' germination requirement and (b)how warm can I rely on it being here in Edinburgh and when. So here goes.

How warm does it have to be before seeds germinate?

There's a cracking table circulating on the internet that results from some experimentation done in the eighties. The only problem is that the information is a bit too concentrated. Here's the chart:

note - click on frame to expand charts



Not clear is it (and there are 3 gaps with no data)

So extracted from the chart here's the information about "% germination" at different teperatures:



and here's the information about days taken to emerge at different temperatures:



The dark green boxes indicate the best germination rates, but the light green boxes indicate enhanced germination rates. The white boxes inicate unfavourable conditions and the blank boxes indicate that it's a waste of time even trying under theses conditions.

When you've got maximun % germination and quickest emergence then you're on a surefire winner. But another factor has to be added that is 'earliness' because its all very well germinating beans at the height of summer but if there is not enough time for them to grow beanspods before the first frost kills them So generally there should be a bias to the left most green shaded boxes.

How warm is it in Edinburgh at this time of year?



or pictorally



Crikey this is bad news. The average Max temperature is 18 whereas my Optimum Germination charts suggest you need at least 20, better still 25 to get the best results. The record high in the last thirty years is less than 30 degrees. Conclusion, in theory I shouldn't be getting a return off my plot at all?

I'll have to return to this after I've had a lie dow. But in the meantime I can see that it's far too early for me to start sowing.


Song of the week: Wonderful World (Don't Know Much)~ Sam Cooke

Brass(ica)ed Off

Sorry to report: the brassicas have come to a premature end. The pigeons ate the curly kale and the the cavelo nero through the netting. First the snow weighed down the netting - and the curly kale went. Then the central pole keeled over/broke through the plastic netting and the pigeons went to town on the cavelo nero. Next year I'm going to stress test the brassica defence system. It's war!

On the plus side the cabbages were too low for the pigeons to get to and have kept us in greens throughout. Also how can you resent beeing outwitted, even by bird brains, when they are struggling through the worst winter in years. It's just that kale is such a Caledonian/Latin tradition...

Big effort this weekend 2 hrs Saturday sorting out the brassica mess and finished digging manure into the 'Others' patch. Dug up the last parsnips and (shame, shame) the very last of the potatoes. 2 hrs Sunday preparing the carrot zone and ...planting posts for next years brassica patch.

Time spent: 4 hours
Money spent: £20.99 ('Walk-in Greenhouse' 19.99, seeds(2pkts £1))

Song of the week: Ain't That a Shame ~ Fats Domino

May The Force Be With You

Meet 'The Enforcer':



My latest acquisition, Davros, before becoming a compost bin is to star as a forcing bin for my rhubarb.



My visit to the plot was curtailed as the ground was frozen, but I scoured a base for Davros around a rhubarb plant and pegged him down. Opening night is about 8 weeks from now!

Weekly Stats:

Time spent at plot: 30 mins
Money spent: £68 (£60 annual rental + £8 for Davros)

*Song of the week: Cold as Ice ~ Foreigner

*Song of the week comes courtesy of The Drooling Vegetable (Retd)