Papery pea plants

[Sylvan]

I started some peas and broad beans inside at the beginning of February and planted them out on 8th April. They've grown since then, despite the cold weather.
Over the last week we've had temperatures dropping as far as minus 5 again. Most of the more exposed Douce Provence and Shiraz plants are looking and feeling papery. Is that due to the frosts and are they likely to recover?

[nickdub]

Are the top of the plants still green and putting on new growth ?

[Sylvan]

Just the very tips.

[nickdub]

should be fine then - odds on the papery bits got too cold at some time.

[Snoop Puss]

Never grown Shiraz but Douce Provence are extremely hardy in my experience. I'd have thought they'd be OK.

[Sylvan]

Thanks nickdub.

I was going to sow the Douce Provence in the autumn because they said they could be over-wintered.
Good thing I didn't if they're complaining about a couple of nights at minus 5. We had quite a few minus 15s earlier in the year!

Last year was the first time I grew Shiraz, Snoop, and we had millions of 'em, so I've sown fewer this year and will be comparing them with four other varieties.

[Sylvan]

Well, maybe not "millions".
I picked 2,197 before I stopped counting and about a week after that I got fed up of going out in the rotten weather to harvest them so just let the rest grow massive and leathery

[nickdub]

No problem at all - I can't be sure of course, there may be some other problem - peas are very hardy, but I'm guessing you started these in the warm and then they went outside without the intermediate hardening-off or toughening up stage. Plants which will stand a lot of cold still need to be introduced to it gradually.

[mothhawk]

I've nothing to say about peas, but just wanted to say welcome back Sylvan. You've been away too long.

[Sylvan]

No, they were hardened off and they were quite happy outside for three weeks after being planted out.
If it's the cold that has caused the problem it will be the week of sub-zero temperatures we just had.

[Sylvan]

Aww, thanks mothhawk

[nickdub]

No, they were hardened off and they were quite happy outside for three weeks after being planted out.
If it's the cold that has caused the problem it will be the week of sub-zero temperatures we just had.

OK - I'm definitely wrong on the cause then - I still regard the fact that theyv'e got green tips as meaning they're likely to start growing again, but of course without knowing what's caused the papery effect its impossible to be sure.

[Sylvan]

Well the temperature didn't drop below -3 during the first three weeks.
It didn't go down to -5 till last weekend.

Could it be the awful biting south-easterly wind that did it?
The Nairobi in the western bed are fine and the Delikett and Twinkle behind the rhubarb have only turned white near the tops (which were sticking up above the shelter)

[Penellype]

It could definitely be the wind. Most frosty nights occur in calm weather when the cold air sinks to ground level and there is little wind to stir it up. The recent cold was unusual in that it was windy at the time. Wind chill is calculated using the wind speed and current temperature and surprisingly there is no standard formula, different countries using different formulae and the way it has been calculated having been changed from the original system (I didn't know that until I tried to look it up just now). I'm therefore not even going to try to explain it, but there are online calculators that give an idea of what the temperature feels like at given conditions. The units measuring the temperature and wind speed have to be from the same system, so if you want to use mph you have to use fahrenheit, and for centigrade temperatures you need km/h wind speeds which are rarely quoted anywhere.

There is a useful calculator here Weather: Weather Calculator which enables you to convert your known values into the correct units for the calculation. The wind chill calculator then gives 2 values of the wind chill - the original (Steadman) value and the later adopted "VS" value - these are surprisingly different.

At temperatures of -5 a wind speed of just 30mph gives a Steadman windchill of -18.1 and a VS value of -14.8. If you consider gusts of 50mph the Steadman value is a bone-chilling -25.3, while the VS value is -16.9. I'm not surprised unprotected plants were damaged by this, even if they are supposed to be hardy.

[Sylvan]

Thanks Penellype. That's fascinating. I shall have to bookmark that site for further exploration

Just noticed some of my Perennial Kale leaves had gone white and papery too, but it seems to have grown past them.

I'll have to remember not to plant anything out in April without cloches or wind netting!