Purple stem/leaves doesnt improve with warm weather?

[emcd124]

I have a number of seedlings that I started from seed this year. They are planted in promix and were wintersown outside in milk jugs.

Of the 10 or so varieties I started only two seem to have produced small but healthy green seedlings (a GWR cherry and Golden Champion). The rest (Mex Midget, Super Sweet, SNFLA, Blondkopfchen, Chocolate Cherry and Gold Medal) all are tiny, spindly, with deep purpling on the stem and leaves. They are runts with curling suffering leaves and have stayed more or less that way for three weeks now with little growth.



Internet search suggests cool weather produces purpling of stems and leaves (perhaps because it stunts phosphorus uptake). The recommendations typically seem to be to just wait it out because it will correct itself once weather warms. But these plants have been outside in very warm weather for the past two weeks: at least 70-80 during the days and above 50 at night. Yet they seem to show no signs of improvement, and if anything the purpling is getting more pronounced and the leaves curling more.

Questions:
1. How long a period of warm weather does it typically take to correct the problem? Should I have seen improved growth and greening with 2 weeks of good weather?
2. Other than waiting, is there anything else I should do for these little guys? Repot them?
3. Is there any chance these will still recover in time to be viable plants in my z5 garden or is it time to abandon hope of growing from seed this year and resort to some sad big box starter plants?

[ScottinAtlanta]

How much water do you put in there? They seem perhaps over-watered to me.

[bughunter99]

Tomatoes are very resiliant when they pout from cold weather This could be that. They do not like cold nights.

The soil looks wet with a lot of debris in it, debris that if is decomposing can rob nutrients. Viral conditions can do this too.

I would inspect for aphids and thrips and then repot each of them individually, and deep. (Plants stay small if pots are too small, too close)
Use a different mix if you can. Apply a balanced fertilizer at half strength.
Allow the soil to dry out completely between watering. Then see what they do. You don't want to plant them in the garden if they are sick. (They might not be.) They might have just seen too cold of night temps in too wet of soil when too young.

[travis]

Since you have lost your cotyledons, the sprouts now have available only what nutrients are in the potting mix. I don't know whether it's excessive dampness or excessive cold air or mix that caused the cotyledon damage and subsequent phosphorus deficiency. You may be drowning the roots. I cannot tell at this point.

What I would do is immediately pot the sprouts up to individual cells at least 2-inch cubes or larger, the deeper the cells, the better. When you do this, insert the sprouts deeply so that the remnants of the cotyledons are at or below the surface of the potting mix.

Then put the cell tray or the individual cells into a tray of some sort that can hold water, like a shallow Tupperware storage box, etc., and BOTTOM WATER the cells so the water is drawn up into the potting mix rather than dousing the sprouts from above.

Here is what I suggest you BOTTOM WATER with: In one gallon of water, add one/half to one Tablespoon of Peters, Expert, or some such Miracle-Gro type HIGH PHOSPHORUS, "BLOOM BOOSTER," Rose Food, or whatever other catchy marketing name the company calls it. Basically this will be something like 18-24-16 analysis, or maybe 15-30-15, whatever. Look for the high middle number in the N-P-K analysis, Okay? The brand name is not important, but do look to see if the product contains micronutrients as well as the macro-nutrients.

PLUS: 1 Tablespoon of Epsom salts, AND 1 teaspoon of Ferti-lome Chelated Iron Supplement.

Bottom water with that mix ... the half TBS or so fertilizer crystals, the TBS Epsom salts, and the TEASPOON of chelated iron liquid in one gallon of water. Mix well before applying.

Now, I am not trying to start a discussion on the pros or cons of synthetics vs organics, or the corporate source of the nutrient supplements. I am only trying to save those seedlings. And to that purpose, I am supplying methodology that has worked for me without fail.

Note: I leave the newly potted up and fertigated seedlings in the shade for about 12 hours, overnight or whatever, to adjust. I also pour off any excess fertigation from the tray after the cells have absorbed enough that you can see the surface of the potting mix has darkened and when you press your fingertip to the surface of the mix, you can feel dampness but not see a puddle in your fingerprint impression.

Then I reintroduce the seedlings the type of light they were previously exposed to. BUT, photosynthesis is necessary for the sprouts to begin manufacturing their chlorophyll and auxin so they can bring themselves out of their currently severely malnourished state. And do not suffer them any chronic wetness as drowned roots can cause this situation as well.

After that, sunlight is their best redeemer. But I do not know whether you have begun hardening them off, or how much sunlight they have been exposed to so far. So, if they have not been out in hard sun for 6 to 10 hours a day yet, introduce them as you would normally harden off seedlings. All my stuffs been out in hard sun for weeks, but I'm in Zone 6b at the opposite and southwestern tip of the state.

[JamesL]

What everyone above said. Cold would not appear to be the issue at this point.
2 weeks is about right to take care of any purpling due to cold.

[travis]

As far as the comment about debris in the potting mix ...

Since the recent hurricanes that hit the Northeastern U.S., Promix and Baccto potting mixes have been (for the past two years) rife with little twigs, roots, etc., that comes from the severely damaged peat bogs. This is a situation that persists, and there is nothing we gardeners can do about it but sieve our mix or use as it comes out of the bag or bale.

I have not found that to be a problem except when germinating seeds. Yes, this year I added nitrogen to my seed starting mix to counteract this problem a bit. And it worked for me except with Suncoast seeds, which are extremely difficult to germinate anyway.

[emcd124]

These little guys have spent their whole lives outside. They germinated inside a taped-shut milk jug outside, and then when the weather got up around 70 I opened the milk jugs so they wouldnt roast in their little green houses, so they are certainly hardened off.

The potting mix was moist like a damp sponge when the seeds first went in, and then I add no additional water beyond what mother nature supplies.

I will repot some of the better looking ones today in some deep solo cups, try watering with the dilute nutrient mix and keep my fingers crossed. How much of the current potting mix should I get rid of when I repot? I can cut in closer to the plant but then I risk damaging the roots. Or should I cut a larger chunk out when I repot them?

[ScottinAtlanta]

I would get rid of it all. I actually wash the root ball when I repot (using an Actinovate mix). That way, you can see how the roots are doing and if you have a problem with root rot due to to over watering.

I don't think it is a great idea to water seedlings in a container from "Mother Nature" rain. She can easily over water since she is planning for ground water, not containers. Water must be carefully controlled to reduce risks such as yours.

[BennB]

What type of ProMix did you use? ProMix is a brand that has a lot of different products and varieties. This year I did starts in ProMix HP (high porosity) that does not have any compost or debris in it.

Tomatoes are resilient and I would not abandon all of these, but I think you might want to consider having a back up plan in place so this year is not a bust if they don't recover.