Slow Growing Pepper Seedlings

[phkc070408]

I started my pepper seeds indoors in Mid-January. I've been trying to keep them in ideal conditions, but they seem to be growing very slowly.

I took the heat mat off about a month ago, but I'm keeping them warm through 2 heat lamps. 1 heat lamp is always on, since my basement is about 62ºF. The second heat lamp runs for 16 hours per day and is in sync with the grow lights. I also would occasionally have a fan on them.

They look healthy, strong stems, but they just aren't growing much. I'm just now beginning to see tiny sets of true leaves.

The only mistake I knew I made was I only had 1 grow light on top of them, and thinking back, it probably wasn't enough. I now have 3 lights on them. Note that the crate is homemade, 26" cube. My grow lights are 12 inch square.

Water has been somewhat frugal, trying to get the roots to grow down. They've never been drenched. I would allow the tops to dry out completely a few times to prevent mold, etc, but as far as I know, the bottoms of the cells have always been at least a tad moist. I water at least once every other day, sometimes every day if I give them less, again, trying to get the roots to grow deep.

Any ideas what I'm doing wrong, if anything?

Thanks

 

[Chuck]

If I were to guess I would say that the soil temperature is too low and probably the ambient temps as well. Try to keep both between 75F-80F

 

[phkc070408]

I did have heat mats on them, maintaining such, but I pulled them about 2 weeks ago, thinking maybe they were getting too much heat . Do you think I should put them back on? I do have the one heat lamp on constant, to keep the temp from going too low. Air temp is about 70º when the one light is on and goes to 85º when both are on.

Also, since they're in a confined space, wouldn't the heat lamp heat the soil as well?

Is it too late to save the peppers, or are they still good?

 

[Chuck]

I did have heat mats on them, maintaining such, but I pulled them about 2 weeks ago, thinking maybe they were getting too much heat . Do you think I should put them back on? I do have the one heat lamp on constant, to keep the temp from going too low. Air temp is about 70º when the one light is on and goes to 85º when both are on.

Also, since they're in a confined space, wouldn't the heat lamp heat the soil as well?

Is it too late to save the peppers, or are they still good?

Being unfamiliar with your growing enviornment I cannot tell you for sure if both lights on will give enough heat to maintain a specific soil temperature. All I can say for sure is that you really need a soil thermometer to actually know. I would keep both lights on. If your heat box has a lid I would open it enough to maintain a 75F-85F range. It appears that most of the seedlings have the beginnings of true leaves. Starting now I would feed the seedlings with a good liquid fertilizer such as Medina Hasta Grow @ 1/2 the rate as per the directions. Your peppers look good but they could look a lot better. Many of the seedlings are getting leggy which means you are probably not giving them enough light.

 

[Martin Mikulcik]

If you can raise the flats closer to the lights it'll go a long way. Inverse square. If you half the distance you quadruple the intensity.

They look yellow but I'm not sure if it's a white balance issue caused by the purple lights or a lack of fertility or in extreme cases insufficient light.

But if the temps and fertility are good it's almost certainly not enough light. For an area that size i use 21 3w purple leds, i guess 60watts, and keep it about 5in from the top and my lux meter said it was roughly equivalent to the par light from part shade in summer

Definitely not too late

 

[phkc070408]

OK, I'll try and raise them closet to the lamps.

I do admit I didn't give them enough light in the beginning of the process, using only 1 12 x 12 grow light for the entire box. I hoped that adding two more lights would be enough, but it sounds like that still might not have been enough.

 

[Ostrodamus]

Get the seedlings to around 8" from the lights. Temps up, and it really looks very dim to me. My peppers are light sponges. Leggyness is generally indicative of lighting issues from my pepper experience. I grow around 30 plants/15 varieties every year.

 

[phkc070408]

So, I raised the seedlings after the last post, about 10-12 days ago. I have 2 heat lamps in there. One is on constant, and the second comes on when the lights come on.

16 hours of lights and 80º temps, 8 hours of darkness and 65º Temps.

Not seeing much action. Decided to raise the plants even closer to the lights. See photos

 

[Ostrodamus]

What lights are you using? Specs? I had trash lights my first season and I was just running up an electricity bill for no reason. I can't tell what the 2 LED style lights are on top.

As for the other two bulbs. I have to be honest with you; those look like more reptile terrarium style lights. I have absolutely NO experience using single bulb style lighting for any of my seedlings. I'm assuming those are only for heat?

Plain and simple, if your temps are accurate then your light is the culprit. I am certain they're starving for light in both volume and intensity. Are you able to read PAR from the lights? I have a PAR meter from Amazon that was like $30.

For reference, here is how close I have my pepper starters. (I can't find seedling photos under the lights) They're about 4 weeks old here, but I really didn't move them much from seedlings. With this light setup I'm able to keep them at 2-4", but my typical stronger lights are 6-8".

 

[phkc070408]

Here are the lights I use:

Link

The other two bulbs are for heat only. One is on at all times and keeps it at 68º-70º. The second comes on with the lights and brings it up to 80º for 16 hours.

 

[Ostrodamus]

Here are the lights I use:

Link

The other two bulbs are for heat only. One is on at all times and keeps it at 68º-70º. The second comes on with the lights and brings it up to 80º for 16 hours.

Ahh, it becomes clearer now. Those lights are rated at 45W (90W total), which is too low from my pepper growing experience. I tend to stick around 150W output because they're light hogs. Wattage IS only part of the equation, so if you push those seedlings up as close as possible, you can still do OK I imagine. I would get stronger lights.

Pepper Geek recommends 150W as it turns out. They're a trusted pepper source.

As for the heating bulbs, they'll provide little heating to the soil, outside of the very surface. Ambient temps don't really matter as much as the soil temps do at this stage. So now I'm suspecting (as others have stated) that your soil temp is low and your light is definitely underpowered.

 

[phkc070408]

Ok. Thanks for the feedback.

What’s interesting is my tomatoes and some of my other crops are doing great with these lights.

I just today, found a YouTube video that gave good specs for using regular lights as grow lights. He recommended between 4500 and 6500 Kelvin and 1500 to 2000 Lumens. What’s everyone’s take on that? I’ll just get 4 A19 bulbs and mount fixtures on a piece of plywood that will rest on top of my case.

Thanks

PS - Is it too late to save these, or can it still be done? I can put the heat mats on tomorrow morning, and build the new lighting assembly this weekend.

Also, if I do save them, can I still get a good crop this year? I’m I’m not going to get a good crop until August or September, I’ll just buy plants at the nursery this year.

 

[Ostrodamus]

At 2 months old with a full set of true leaves and a 2nd set starting, they're not beyond meaningful production this season if you correct the soil temp and light output immediately. It'll be Aug-Oct for sure. For reference, here in zone 6a I started this season's seeds only 10 days ago.

Bottom line is that they're pale and becoming leggy which indicates poor light exposure more than anything. If you don't correct this then no matter what age your plants are, they'll stunt and ultimately fail. You can also wrap the tank in foil to reflect light back inwards. Once you correct those issues, wait a week and then introduce 1/4 strength dilution all-purpose fertilizer to assist with bringing color back to them.

 

[Ostrodamus]

Are those jalapenos? Hot vs superhot vs green? More for curiosity than anything.

 

[phkc070408]

A wide mixture. 8 different types

I’m probably going to give up on these. I don’t want to wait that late for a harvest. I’ll buy plants from the store.

I will, however, take the lessons learned and do a practice tray over the summer - see if I can do better. This way, come next year, I’ll be ready to go.

Also, over the summer, after my basement isn’t full of plants, I’ll build a new lighting fixture for the top of the housing.