Grow bag seedling leaves dying.WHY? with pics

[growbags]

Its the beginning of autum here in South Africa and I'm trying to grow some lettuce and spinach in a home made 1 metre grow bag. I'm using potting soil that i washed through 80% shade netting. The soil drains very well and holds moisture too. The bags are under 40% shade netting so the seedlings dont get burnt but the seedlings sprout and a few dys later the ends/tips of the leaves look like they drying or something. next day the leaves are shriveled and dead but the roots and stem look great! I though it was sunburn so I put up the shade netting, but the first seedling to do this was on the south side of the grow bag which gets very little light because of a wall behind the bag.

Please see pics attach. I am so confused!

It starts with the tips or edges and the next day the leaves are dried up and shriveled. Roots and stem look good.

Please help

[shirlthegirl43]

Is there any chance that condensation is gathering on the leaves causing scorch?

[Florence Fennel]

Would you be better sowing the seeds in trays and then potting into the grow bag when you have stronger little plants? Just a thought.

[taff]

Not sure exactly, but your soil [?] seems to be full of bark or wood [in the first seedling picture as well as the grow bag]? If is is, I think it's burning the seedlings.
I have no idea what conditions are there at this time of year, so honestly, it could be anything or a combination of things, like heat and light levels etc.
I'd try a softer mix to start them off in, and transplant when they're bigger. If they do better in an mpc mix or a seedling mix, you know it's the compost.

[growbags]

Is there any chance that condensation is gathering on the leaves causing scorch?

Scorch? the sun burning the leaves because of moisture on them?

It happens on the south side too where very little direct sun light is.

[growbags]

Not sure exactly, but your soil [?] seems to be full of bark or wood [in the first seedling picture as well as the grow bag]? If is is, I think it's burning the seedlings.
I have no idea what conditions are there at this time of year, so honestly, it could be anything or a combination of things, like heat and light levels etc.
I'd try a softer mix to start them off in, and transplant when they're bigger. If they do better in an mpc mix or a seedling mix, you know it's the compost.

The wood is from the potting soil, so has been well stabilized. How can stabilized potting soil burn the leaves. What exactly burns the leaves?
Thanks

[Nicos]

To be honest- I think they're far too tiny to be planted out like that

Personally I'd be waiting until they are much bigger.
...and as FF and taff have said, seedlings need very different soil to 'young/adult' plants.
Can you take the others out and put them in seedling compost until they are larger???

we plant ours out at this size



(How cold is it at night???)

[growbags]

To be honest- I think they're far too tiny to be planted out like that

Personally I'd be waiting until they are much bigger.
...and as FF and taff have said, seedlings need very different soil to 'young/adult' plants.
Can you take the others out and put them in seedling compost until they are larger???

we plant ours out at this size



(How cold is it at night???)

Its starting to get a bit cold at night but no frost untill june/july.

Nicos I planted the seeds in the grow bag, no planting out.

Please help

[Bigmallly]

Scorch? the sun burning the leaves because of moisture on them?

The moisture on the leaves act as a magnifying glass & as a schoolboy, I'm sure you know what a magnifying glass & the sun is capable of......

[taff]

The wood is from the potting soil, so has been well stabilized. How can stabilized potting soil burn the leaves. What exactly burns the leaves?
Thanks

unless it's well composted it can be high in tannins and I don't know which tree they came from, but some are acidic, like firs etc. They'll also use any nitrogen available to keep composting

[zazen999]

One of the things I learnt in my Grow Healthy Plants course was to start plants off in modules or pots, pot on into small and increasingly larger pots [where you can control conditions] and only then plant them out. It really improves the quality of the plant and the number of seeds sown [and thus lost] and I swear by it.

[shirlthegirl43]

unless it's well composted it can be high in tannins and I don't know which tree they came from, but some are acidic, like firs etc. They'll also use any nitrogen available to keep composting

Taff, I understand your point but I am unsure how common fir trees are in South Africa.

[taff]

Taff, I understand your point but I am unsure how common fir trees are in South Africa.

fir trees are just an example, I have no idea what trees grow in S.A. that have the same kind of resins. Like balsams etc.

[growbags]

unless it's well composted it can be high in tannins and I don't know which tree they came from, but some are acidic, like firs etc. They'll also use any nitrogen available to keep composting

Taff, im using washed commercial well composted potting soil. The roots and stems are fine.

[taff]

have you used the same one before with no problems? and where's the water that you're watering with coming from?