Winter Lettuce seedlings – Mildew !

[dan hazelrowanParticipant]

Hi Charles

Oh dear – my precious winter lettuce seedlings are succumbing to mildew!

They have the white dusty growth on the leaves , which when touched release spores. I have lost about 20% of plants so far – worst affected are grenoble red ! lattughino and meraviglia d’inverno are much healthier

So I have taken them outside the tunnel and removed as many damaged leaves as possible and just cross my fingers!

So..do you think i should just plant them out – they are obviously not happy in the modules, perhaps in the ground, with some seaweed they may perk up?

I think the horrid damp warm weather is to blame, and also when i pricked them out it was scorching hot here and so i had to soak the compost to prevent them utterly wilting – then shortly afterwards the sun vanished and the seedlings were perhaps too damp –

The only consolation is i have extra claytonia plants – as i had a lot of trouble getting them to germinate as it was so hot i’m guessing .. so my sowings for outdoor cloches germinated late and are on the same level of growth as my 2nd tunnel sowings..

Endive seedlings in the tunnel next to the lettuce are ok – but some have a kind of tipburn rot on the very end of some of the leaves … not too bad though… yet..

tricky autumn weather!

dan

[charlesModerator]

 Hi Dan, maybe it is less severe than at first sight, as you say the weather has been perfect for the mildew.

I am unclear if you mean it is on seedlings in trays or already planted?

Whichever, I have rarely known mildew to kill lettuce esp. Grenoble Red. I would take off the worst affected leaves and water as little as possible, you may have over-watered. This is now a time when watering can easily be ooverdone and I have watered my plant trays just once in the last five days, because of the 100% humidity. While winter purslane and the brassica salad seedlings are indeed very healthy!

Main point – water seedlings/plants less than once a day from now, eg every three of four days, check first, lift trays and if quite heavy, don’t water! Water in mornings only so leaves can dry before dusk.

[dan hazelrowanParticipant]

thanks for your optimism charles

yes the lettuce, and the endive which was next to it on the shelf in the tunnel are in modules, i wonder if should let the lettuce try and recover in the modules, or just get it in the ground?

What is interesting is that the bubikpof, lattughino and meraviglia are all slightly affected by the mildew, but it is not concerning , they look ok – however the grenoble has taken a big hit, i will take a photo tomorrow and send to you.

So i’m wondering if the grenoble red seed (seeds of italy) is from a plant of weak constitution..?

As for watering – i have been aware and thinking of that – and indeed i haven’t watered them for a good few days

but earlier in the month i found it extremely challenging for seedlings – when the sun was out, the heat was so intense i has to water 3 or 4 times a day to avoid wilting. Also several seedlings were simply frazzled! this was much worse than in the summer heat of this year..
And as i was pricking out the lettuce during this sept hot spell, i was generous with the water – and perhaps too generous!

In fact even today when the sun came out – i had a few wiltings even after a light watering..

quite a challenging time for gardening i’m finding!

[charlesModerator]

 this wilting in October sounds wrong, which compost is it? Are the cells well firmed with compost? after you water, is the cells’ compost fully moist? (it should be so they are moist for a long time)

I would put the mildew plants outside with air around them. Still think they will be ok.

[dan hazelrowanParticipant]

compost is new horizons organic – and has been dutifully firmed into the modules – all other module growth is and has been healthy –

However on the lettuce modules there has been a lot of fungal fruiting (tiny little ‘cups’) on the compost surface –

I think with the wilting yesterday – the modules were too dry , i was concerned about over watering! They hadn’t been watered for a few days, and i only gave them a light watering (not enough to soak) , before the wilting occured. Then a good soak remedied.
Also the wilting usually occurs at the edge of trays, and at worst towards the south side of the tunnel, the shelves and tunnel run east west.

Generally though here in our sheltered steep south facing valley i notice (due to sun trap effect) , when the sun is out it feels much stronger and more intense than elsewhere. Even this morning i am now in a tshirt.

Also our tunnels have anti-fog thermal plastic on them – so perhaps they get hotter than normal plastic?

But these factors combine to make it tricky, as plants need more water to cope with the intense hot periods, and then stay damp when sun goes.

Lettuces are outside now in some glorious autumn sunshine, so i hope over the next few days they recover!

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