Partially Germinating Tray? What to do?

I have several 132 count trays that have only partially germinated. I would like to take the domes off, but will that bother the ungerminated ones?

Hi Chuck, and welcome to DG!

I'm probably not the best one to answer this, but hopefully someone will come along that has a better answer.

What's growing in the trays? Are they under lights or on a heat mat?

What I've been doing this year with success is taking the tray off the heat mat when I have some germination, and placing the whole tray under growlights that are only about 2 inches above the tray. I prop the dome partially up until I have more germination, and if some of the first seedlings get their first true leaves, I get them out of there and transplant them. I've had pretty good luck doing it this way, and haven't had one seedling dampen off yet.

DH laughs at me, because I have so many stages going on: He's named them.

Nursery school (on heat mats on kitchen counters)
Grade School (under the growlights with lights close to plants)
High School (Still under growlights, but lights raised higher)
College (Outside in patio awaiting graduation into the real world)
Adulthood (when they are planted outside and have to become somewhat independent from me)

Thanks for the info, It is too hot to use the heat mats or keep the lights very close, so it is just the drying out that I was worried about. The other seedlings in that tray only have the two leaves, so it is pretty early. I have been watering from below every three days or when the tray feels lighter and have a layer of perlite on top. Who knows when the inula will sprout. Everything else sprouted much faster than it said. No evidence of any damping off, so I suppose it will not hurt to keep the dome on a day or so more. They are scheduled to be watered tomorrow, though the trays are still pretty heavy.

I didn't check to see where you are located, but I can see in California that it would be too hot for that. Hopefully someone in your zone will be along to help you out. Good luck!

Yeah, it does get warm, now I have to keep the garage door open to keep things reasonably cool. Turn off the lights for quite a while during the day if it gets too hot.

Yes, Joan is right, it seems to be a good idea to get a little ventillation going for the ones that have germinated. Propping the dome up on one side will work. I took my dome and poked a lot of little holes in it using a metal skewer (heated tip on stove burner), and that's what I use. It keeps in plenty of humidity for the seeds that haven't germinated yet (I even see some moisture droplets forming on the inner surface), but it seems to release just enough moisture to keep the seedlings happy (no damping off in my experience).

If I have just one row or a couple of 6-packs that haven't sprouted yet, it also works fine to lay a bit of plastic over just that area (a baggie, a strip of bubble wrap, a piece of Press 'n Seal wrap, whatever is handy).

Joan, I love DH's seedling stage names!

Thanks for the info. I will try that. None of the multitudinous seeds have gotten beyond the two leaf stage yet. I am surprised at how tiny the amaranth seedlings are. It is going to interesting picking those out

Chuck, now that germination has begun, do you really need the heat mat? That has got to be drying things out. I don't use heat mats, but I probably don't start all the heat loving plants you do. Anyway, when germination gets going, I move the containers into another flat and begin watering from the bottom without a cover. I've also found I don't need to have the fluorescent lights right on top of the little seedlings. Mine are about 5-6" away and the plants aren't getting leggy. I am using 40wt cool whites, I believe.

Yeah, that is where I am. No heat mats, lights over a foot away. So far, no leggy seedlings and everyone is happy. Just checked and it was 80 out there, so I turned off the lights and opened the garage door. I have permanent fans built in that provide reasonably good circulation. Got some hydrogen peroxide to use for the brugs/daturas and to water with. I use the home depot shop lights with cool white 40 watters which provide plenty of light and heat. So far, the heat has not been a problem.

I've been keeping my peppers on the heat mat until I've transplanted them from the starting tray into individual cells/pots. With tomatoes, I've discovered that it's best to move them off the heat as soon as you see signs of germination, or they get leggy. Other stuff seems variable. A happy medium for me, when I have extra space in the flats on the mats, is to take my little tray/cup with germinating seedlings and put something under it to A) raise it much closer to the light and B) reduce the heat a little by lifting it an inch or so off the heat mat. This is my first year with heat mats, so I've been learning as I go!

Chuck, if you can, I would move those lights closer to your seedlings. Two to four inches seems to be ideal. Maybe you're getting too much heat buildup under the lights and that's why they're so far away.... then again, if it's working for you, then it's working!

I never mix varieties in the same tray because of the problem you are having with the seeds germinating at different times. Al

It all worked out, I just kept the lids on the slow germinating trays until the others germinated. Of the 72 different kinds I planted, the only one that hasn't germinated is the Inula. These were all easy stuff. I think I will switch to using breakapart type, so I can separate the ones that have germinated. I was mostly concerned about the damping off, but none of that has shown up and I have been very careful to water from the bottom, though it is time-consuming.

I stick wooden skewers into the corners of the tray to raise the dome up so the seedlings don't brush against it. If your seedlings have their second set of leaves there will be enough humidity around them to allow the late germinators enough. Jessamine

That is a great idea. My next step is to start transplanting to larger pots. Corn, after four days, looks ready. I only did the tray thing because there was no way to keep them wet all the time where they are going to end up. They need to be able get along on being watered twice a week via drip. 4" or tough ones in six packs is about what they need to be. I went way overboard on the amaranthus, but I think I will just transplant the clumps and let the plants sort it out for themselves.

Have started to move the seedlings to 4" pots. Haven't lost any so far. I am acclimatizing them in the garage with the door open. So far that seems to be enough light. It should be OK to move them out onto the driveway in the shade in a day or so. I will put the smaller stuff into 6 packs next. I used a mix of compost and perlite 50-50. So far so good.

Almost everything is up. The only things that got really leggy were the sunflowers, which I probably should have just direct sowed. They seem to need very strong light. I am going to be gone for a few days, so everything will get transplanted when I get back. The first batch moved to the driveway and is doing fine. I did get some algae growth on the perlite, but no sign of any damping off. Watering from below worked out fine. I started doing four trays at a time and that was about right. The first one was done when I got the last one filled. Putting the marker in one corner and x on the spread sheet worked out well, though it is pretty easy now to spot the difference. I planted way too many of each. I am going to switch to two rows of eighteen next time and probably go down to one. Germination rate was very high for the most part. Just a couple of the CA natives had lower rates. Nothing really hard yet, have one more batch of easy stuff and then the hard ones from Africa nd Australia.

I haven't started corn inside in years. One thing I did learn is to get them in the ground before they are more than 8 inches tall. I rarely put them in pots and when I did I used newspaper pots. They transplant to the garden bare root just fine though. Jessamine

had I been able to water them conveniently, I would have direct sowed. Seeing what kind of roots they put out 4" in two days, the drip probably would have worked. I have them in 4" pots and they are coming along nicely. Probably try and plant them in a week or so. They should be able to make it for three days between waterings by then.

Chuck,

Thanks for starting this thread and a couple others. I am a germinating novice so do things on a small scale in bits and pieces.

Last year I bought a system of germinating trays somewhere online. The seedling cells are 6 pack breakaways. Watering from the bottom is easier because you simply lift up one 6 pack and put the water in the bottom that way.

Now in my learning process, I find that I may have to refridgerate a couple six packs if I don't get germination. I have a small apartment size fridge with no handle and a hole in the side of the outer wall, duct taped. I originally commandeered this unit from my son for beer and sodas. Now I've decided I can spare a little room for seed stratification or cold spells for zone 9 plants. Still leaves space for a couple Bud Lites.

I'm learning from yall, thanks

Molly

It looks like there is an old refrigerator in my future, both for storing seeds and cold stratification. I think I can sell it as a way to avoid tracking dirt into the house by keeping a few sodas in there.

If they don't require a lot of chilling, I found that placing an ice cube on top of the soil a couple times a day works pretty well. I got my Larkspur to finally germinate that way!

Now that's a cool tip, Zarebeth! Umm, no pun intended. ;)

Donna

My husband made my light shelf from a 7 shelf, open mesh wire shelf which is carried by Sam's club at about $60. Lowe's also has a similar shelf but it does not come with wheels and has one less shelf. There are two 4-foot florescent lights hanging from each shelf (except the bottom one). The lights came from Lowe’s, were about $15 each and include a plug on a short cord. The cords are plugged into a plug strip which in turn is plugged into a timer. We set the timer for 12 hours on-time each day. The lights are hung with chain and can thus be raised and lowered as needed. We use plug trays which have 128 spaces that are about 1 inch square and use a very fine seed starting mixture. We got the trays and starting mixture from a place that supplies large growers. We put in one seed per space and leave it until it is root bound which makes it easy to place the entire plug into a 6 inch pot. We learned this from visiting a very large grower.
Joan

That is great! I wish you luck.

I have learned several things out of my first seed germination experience. I used 128 cell trays which were OK, but I planted three rows of two kinds and two rows of one kind. When I had a lot of seed I used it up, unless it was totally excessive. That was too many cells of each kind and too many plants in each cell. Even when not everything germinated I ended up with three times as many plants as I wanted. From now on, no more than two rows--32 cells and no more than four seeds in each hole. I have been potting stuff up in shallow 4 inch sheet pots, which is working fine, but it takes up a lot of room. I think I will switch to eightpacks. Since these are for my own use, there is no need to get them any larger than necessary to be able to survive on twice a week watering.

After potting out 20 different things I still have lots of each kind left. Since there are still things growing in each tray, there is no need to decide what to do with the surplus yet, but it is coming. Very small plants can fill up the cell with roots, so you can plant out a lot earlier than I thought you could. I keep them on the garage floor with the door open during the day for a few days and then move them into the shade in front of the garage. That has worked out well. Even the leggy sunflowers are starting to stand up straight and fly right.

Chuck, Thank you. I had not thought that far a head. What do you do with the rest of your seeds? I be long to a garden club so I can take the left overs to them. I have a very hard time thining out plants. Yes I am one of the nuts that feels like I am killing them. I know in time I will get over it but for now I still plant all the plants. I have learned a great deal from this thread. I thank all of you who took the time to help all of us. Joan

It has been great fun building the seed palace, figuring out what to do with the enormous help here at Dave's, trying it and then seeing what works and doesn't work. It is something I wanted to do for a long time and just never seemed to have the time or energy to take it on.

I have one more set of easy ones and then it is on to the solanaceae with nicking and soaking in hydrogen peroxide, the African stuff with soaking in smoke disks, some of the others than require cold and warm stratification.

Dumping the leftovers is something I need to do, but haven't. The amaranths came up like crazy, but they haven't grown much. They transferred very easily in small clumps. The quinoa did not germinate nearly as well.

If you lift up on the edge of the tray you can tell when they need water, the trays get very light. I got a little die-back on the edges. Those cells do not seem to take up water as well for some reason. The perlite topping worked very well, sorta like icing on the cake. Though it did a brownish crust on it in some places.

I started using one of the two dollar stiletto letter openers which work great. You can slide it down the side of the cell without damaging it and the whole thing comes out easily. I watered the trays before transferring just like you would do if you were planting one gallons which also made it easier.

I think I will switch to the sheetpots for the difficult stuff so it will be easier to split out the ones that have germinated or go to the paper towel method.

Several of the Sandeman Seed supplied seeds came in very large quantities so I can try several different ways.

The restios (a southern hemisphere grass) require the soaking in smoke disks. I think I will try using ice cube trays and a spread sheet to keep the seeds separated. It is nice that Wal+Mart is right across the street for stuff like that. I assume you can tear the filter disk into pieces, and hopefully Wal+Mart has a measuring cup denominated in mililiters.

I've got everything I need to move forward but the sheet pots which should show up today. They had ice tubes, much smaller and more of them. They will use less space being only a quarter to half inch in diameter, small enough to fit through the opening in a soda can.