I looked closely at the stem where it comes out of the mix. It looks like damping off fungus is discoloring the stem. Are you sure you are not keeping it too wet? Al

I think I might have watered too much. Since I had been worrying about humidity, I thought I could add it back by watering lightly everyday. After posting this question, I had thought about the possibility of over-watering, and so I had stopped giving them water for 2 days already. The top of the planting medium is dry, but it is still moist about 1cm down after 2 days. Definately not wet though, just slightly moist. This problem can now be seen on every single one of my collard seedlings (I have 6 pots). I checked on the stem, although there is a bit of purple coloring on them, they aren't tipping over or turing thin and brown. So I hope I'm not over-watering to the point of damping off. The planting medium I used was turface, perlite, akadama, and peat (baked to sterilize).

I have another question regarding temperature. Since I have the plants lined up against a north-west facing window (with metal halides above that runs from 6am-7pm), when sunlight shines through in the afternoon, the temperature of the surfaces where sunlight reaches will rise to close to 90F; eventhough the ambient temperature of the room is kept under 80F. Does it matter? Will the 90F sunlight patch be too hot of the plants? Or is this okay as long as the potting medium is kept cool?

I don't know about the indoor temperatures - if the temperature seems to be affecting the plants (fainting or scorching) you could put up a sheer fabric on the window or if you have blinds lower them and partially close them. Even cheese cloth folded over would help alleviate the heat from the window.

Cheers,
Peggy

It would help us understand your growing problems if you would let us know where you are. You can remove the None in you name and replace it with your zone or location. Al

I live Hong Kong. Does this matter since I'm growing indoors. The temperature in Hong Kong now is around 90-92F humidity 70-80%.

The true leaf that is shown in the second picture now has these white patches on the whole leaf, cotyledon looks the same, but the tiny leaf that is pointing towards the camera is also starting to get these white dots on its tip. I checked the back of the leaf, it has purple veins. I still haven't watered them since I made this post, and I am also opening the windows after the lights are out to let in some humid air. The plants are constantly at 78-80F 24/7. 12 hours under light with humidity around 25%; and 12 hours without light with humidity 50-60%. I'll try to only water once a week from now.

I'll include more information. The potting medium is 60% perlite, turface, and akadama; and 40% sterilized peat. I started the seeds with paper towel method, and as soon as they sprouted, I planted them in 10"dx11"h air pots. I did watered them daily before, and since the pots are quite large, the amount of potting medium isn't drying out very quickly. I just stuck my finger in the medium, and its still cool and moist under the surface. I don't think they will completely dry out in another 5-7 days.

How should I be watering them to avoid over-watering? I'm thinking watering thoroughly once every 2 weeks...but once every 2 weeks sounds so sparce. I googled about growing collards, they're suppose to be very hardy and can even be grown in summer in high heat. If this is true, I might as well turn off the air-con and leave the windows open. This will make the room very warm and humid - 90-95F with 60%+ humidity. Is this true that collards can grow under such high temps? Are we talking about air temps or soil temps?

I will be starting another batch of collards, just in case these ones don't make it. I have one that is shriveled up now. The others still look OK eventhough they have white patches on the true leaves.

Here in California, all our rain is in winter, and as soon as the rain stops the humidity drops to 30 to 60% and down to 20% when we get an east wind. Low humidity is never a problem to rooted seedlings. I think your starting in overlarge pots is a mistake, I would never start in any larger than four inch. I would also start hardening them as soon as possible. I am presuming you are planning to plant these in your garden where they will do much better. Collards are a cool season crop and here they are not usually grown this time of year when the summer heat will usually cause them to have a bitter taste. Al

Hi Al, thanks for your reply. I live in an apartment and intend to grow these collards indoor. That's why I started with 10" pots, so I don't need to transplant them when they grow. I'm growing these for my bearded dragon, because a lot of our vegetables comes from China; and I know they contain all sorts of chemicals and pesticides that are way over the safety limits. I don't want my dragon to die early or develope cancer...so, it is ok if the collards is a little bitter, as long as it is perfectly safe for him.

Although it may seem to make sense to start in the size pot you will eventually need, it does not work out that way. When you water a container, the water can either run out the drain, evaporate from the surface, or be transpired from the plant foliage. Even with a carefully made mix, without substantial amounts of foliage to transpire away moisture, the mix tends to hold too much moisture too long. Most plants will grow best in a mix that goes from wet to dry in a reasonable short time. It is in this cycle that the mix draws in the needed oxygen to facilitate the taking up of the moisture, and nutrients, by the plants roots. Good luck with your dragons, my grandson is a dragon lover. Al

Thank-you for the explanation Al. Most of the seedlings shrivelled up and died yesterday; so I re-started 2 batches in 3" cups this time. When they out-grow these cups, I'll move them to 6" pots then to their final 10" air-pots. I hope I can suceed this time.

I dug out the dead seedlings, their roots are white but very thin and short - less than 2" long. On the other hand, I started some Bok Choi just last week in a smaller and shallower container, their first true leaf is just starting to emerge, but their roots are already sticking out the bottom holes! So, starting with a large container really doesn't work well...plus I watered too much too often. I'll update if my new batch in 3" cups will grow better. Thanks :-)