Hardening off hot pepper plants...

Some advice is requested from folks who’ve done this themselves, as I’m a bit baffled and there is lots of contradictory information on the web that I can’t really sort through.
Anyways, I germinated several different species of jalapeno about a week and a half ago. (Mucho Nacho, mild jalapenos, and ‘standard’ jalapenos, if it matters). I used a disposable roasting tray to store jiffy pots in and used the plastic lid that came with it to make a ‘greenhouse’. The seeds germinated mostly well, with the Mucho Nacho plants being the most robust at about an 80% germination rate. I’ve been keeping the roasting tray on heating pads 24/7 and using an Ott light to give them full spectrum light for about 12-18 hours a day.

Recently I figured that I could save on electrical bills by putting them outside in the sun, and after leaving them out, covered, for about 8 hours in direct sunlight I noticed that one of the seedlings (they’re all at the ‘two leaf’ stage) had some brown spots on its leaves. I wasn’t sure why that was, and put them out the next day, when that same seedling had one of its two leaves turn almost entirely black and shrivel up and the other one turn much browner. , I did a bit of googling, and found out that the problem was that I was not “hardening off” my plants, and that they needed to slowly get used to being outside and in direct sunlight. Okay, said I…

So I waited till the next day and then put the roasting tray out for an hour in the shade, uncovered. There was a very, very mild wind. When I came back out an hour later, all of the seedlings had wilted and slumped over. Most of the younger ones were also covered with brown spots, the mild and standard jalapenos took the worst beating while one or two of the MN plants had some brown spots that didn’t have them this m0orning. I took the roasting tray back in and placed tit back on the heating pads and re-covered the roasting pan with its lid, turned back on the Ott light, and many of the seedlings have now perked up again. I’ve tried checking the web, but I’ve seen advice as divergent as putting them in direct sunlight by increasing one hour increments over the course of a week and then leaving them outside, to gradually putting them on a windowsill with the blinds opened and then gradually opening the window inch by inch over the course of several weeks.

I’ve got no clue about this, as this is the first jalapeno pepper crop I’ve ever tried to start. Are the seedlings with brown on them all going to die, or can I save them? Should I wait a few weeks before trying to harden them again, or what? My plan right now is to keep them indoors, at least over the weekend, so they can get a bit stronger and then maybe start putting them outside in the shade for a little bit each day and increase that time day by day. Anybody got any ideas?

It’s been a few years since I’ve done this, so just going from memory, a few things come to mind…

  • 8 hours on the first day is way too much. I did my first days of hardening off for only 2-3 hours, and stayed at 2-3 hours per day for the first 2-3 days. You probably already know that hardening off is the time when plants get adjusted to bright sun, cold temperatures, and the wind (yes, even the wind matters quite a lot in the hardening off process). Take it very slow and gentle in the first few days.

  • Covering plants in that tiny little “greenhouse” that have already germinated is bad, bad, bad. The little “greenhouse” idea is essential to keep the soil moist when the seeds are germinating, because those germinating seeds need a constantly moist soil. If left uncovered, that relatively small amount of soil can dry out in a blink, killing the germinating process. But once germinated, the cover comes OFF, because that constantly humid environment is deadly for the part of the plant that’s now above ground. At that stage the soil still needs to stay evenly moist with constant gentle watering. But removing the plastic dome gives necessary air to the stems and all parts of plants above the soil. Otherwise stems and leaves will quickly rot and suffer from disease.

  • Covering plants in that roasting pan while outside in the sun also creates a very “HOT” environment. Just think of your car and how quickly it heats up when sitting in the sun, even when it’s cold out. Combining the high humidity under the dome with that intense heat can literally cook and even kill the young plants. You’re likely seeing the results of too much heat and humidity, probably some type of disease that thrives in humidity.

  • Once the plants are past the first germination stage, and have gotten to their 2nd, 3rd and 4th sets of leaves, they are out of the most fragile stage of germination. Hardening off usually comes after about 6-8 weeks (varies according to the plants). Hardening off also varies a bit depending on the needs of the plants, but yes, it generally needs to be a gradual thing. It’s very important to pay attention to fluctuating outside temperatures. Some plants (like lettuce) are very tolerant of cold and can take temps as low as 33-35 degrees F. Some lettuces can even tolerate a little frost. Others (like peppers and tomatoes) love warm temperatures and shouldn’t be hardened off until the daytime temps reach the mid 60s F. Also, the cool-ish temperatures and very intense sun means their first time out should only be 2-3 hours, for 2-3 days. Then increase the time on the 3rd day to 3-4 hours, and the 6th day to 5-6 hours. Maintain that rate of increase for about 2 weeks when they can finally be left out all day, in full sun. All this should also be done while paying attention to temps that dip too low. If the weather isn’t favorable, i.e. goes below freezing, gets violently windy, relentless downpour, let them spend a day or two indoors again until the weather cooperates again. Then out they go again to resume the process.

  • Some shade while outside is good, especially in the first few days. Of course the sun is also good, but some shade gives them a rest from the intense sun.

  • re the wind: for young plants even a breeze is a shock. Consider that they were “born” in a house with no breeze whatsoever. Then out they go where they are buffeted constantly. Some gentle breeze is good, is part of the hardening off process, and gives them a good workout where they build up strength in stems as they get adjusted. But too much of a wind is traumatizing, and they will suffer and won’t thrive in it. If the wind is intense on the first day out, their time out should be cut short. If you have an area where they can be outside while still being protected from heavy wind, that may provide some good options. At times I set mine inside a deep cardboard box to give them a little extra protection. Other times they went back inside.

When you take them back inside, unless the indoor area is below freezing, or below 60 F, just skip the heating pad. It’s not helping to keep them so hot inside while you’re trying to get them used to the cold. My basement stays about 60F in winter and I had no problem whatsoever germinating and growing heat-loving plants without any extra heat source.

Some questions…
How long have you left the ott light on them while indoors? 14-16 hours is best. I used a timer to make sure they didn’t have to depend on me. And hopefully you kept the light down low? About 1/2 to 1-inch above the plants? And check and raise the lights as the plants grow, so the light bulb doesn’t ever touch. The close light height is critically important to healthy plants and stems. If they have to struggle the least bit to reach the light, the stems will get spindly and weak.

Where are you located? It’s still much too cold here (St.Louis, Missouri) for our peppers to be outside for that long. Most gardeners here don’t plant those heat-lovers outside until May. I would start hardening them off in mid April. Peppers (and tomatoes, same family), seriously love the warm weather. They won’t die off in temps at 40-50 degrees, but they won’t grow either. As long as it’s cold there will be no growth, no new leaves, no blossoms, no fruit. They’ll just sit there, languishing, until the temps get high enough.

Have you been feeding them? If they’re onto their 2nd and 3rd sets of leaves, and if there’s no food in your planting medium, they need to be fed. I gave mine a weak fish emulsion, diluted with lots of water. It’s stinky-poo, but the plants really loved it.

Also keep in mind that internet advice is written by people who aren’t necessarily in your same planting zone. Sometimes the writers make allowance for that, but sometimes they don’t.

Peppers on a windowsill? with blinds?.. sounds like very bad advice to me.

A few good gardening books (try the library?) is probably a better idea than using the internet. When I didn’t know anything about gardening I read a few library books and easily figured out which authors really knew their stuff.

FWIW I think you’re doing good by paying very close attention, noticing any little change, then making adjustments when you see something isn’t working. Taking them back inside to start this again, and getting some more info to figure out what needs fixing, all sounds like a good idea.

Excellent, thanks much for clearing up my ignorance. The dome is now off and I will wait another few weeks at least, until they’ve got their fourth sets of leaves, before I try to start hardening them again. As I’m in Texas anyways it should be more than warm enough for them for quite some time.

Hrm. Damn. I’ve been using the light for about 12-14 hours a day, but I haven’t been able to suspend it right above the plants. I’m not really sure I’ll be able to able to either as it’s a light I had from painting miniatures that has a stand and isn’t really adjustable. It’s also somewhat of a small light… Maybe there’s a way I can jury rig something, though. If I can’t bring the light to the plants, I can always stick a few phone books under the tray and bring the plants to the light. :smiley:

They’re still on their first pair of leaves. I will go pick up some tomorrow. How often do I need to feed it to them?

And thanks very much for your help. I’ll trundle over to the library in the next few days and see if I can’t find a good book or three on the growing process.

Oh, and:

The seedlings are in miracle grow planting soil, do they still need to be fed with fertilizer? I assume that it should be a nitrogen rich mix until they’re ready to be hardened, and then nitrogen-low when it comes time for them to bear fruit? Or just fish emulsion from now until doomsday?

Speaking of lights, I’ve jury rigged something but I’m not thrilled with it, the area of coverage from my little light seems a bit low when it’s so close to the plants. Would other options be viable, like normal bulbs in a flexible desk lamp? There’s also something options like this, or this but as I’m not growing anything illegal I’m really not sure that the investment is worth it… but it might be if I’m going to start plants from seeds a few more times. If I go that route I’d think that the bulb makes the most sense as I could screw that into any old bendable, flexible desk lamp and not have to deal with finding a way to rig up a hanging system for an LED ‘tray’ style thing.

Edit: and the more I look, the more LED grow lights I’m finding. I didn’t even know the damn things existed.
I never knew that growing things could be quite so complicated.

My advice would be to NOT buy any expensive lights. I used the most inexpensive 48-inch shop lights from the hardware store, about $10 each. And just regular inexpensive 40-watt, 48-inch fluorescent tubes, “cool” light, less than $2 per tube. But not incandescent bulbs, and not “soft” light either. Lots of growers use extremely expensive set-ups, with special grow lights that cost a fortune. There is something about the light spectrum, and the colors present in the light, that plants especially need. I’d read that 40-watt “cool” fluorescent tubes would suffice for the garden veggies and flowers. So I bought those and had an outstanding success with them. With my cheapie setup I had very robust transplants, bountiful veggies, even blooms on flowering plants (petunias, marigolds, salvia, alyssum, impatiens), while still indoors. All that with the cheapest lights and bulbs I could find. You could get smaller fluorescent light fixtures (about 24-inch) but for some reason those are always much more costly than the larger cheap shop lights and bulbs. I think the more expensive lights are important when the plants stay indoors all year. But for starting transplants for just a few weeks the inexpensive lights are just fine. And for now your ott light seems fine for a very small setup. But raising the plants up to the light would be better too.

I prefer organic, so I personally wouldn’t recommend miracle gro, but that’s according to your own preference. The general rule is that small plants like that do need food, but a very light amount. If your fertilizer doesn’t specify how much for tiny transplants try using 1/4 as much as it says for houseplants. It’s like adding salt to food when cooking, easy to add more, but impossible to remove if you use too much. I also wouldn’t use regular potting soil with fertilizer included, because that’s too much plant food for tiny seedlings. Also, seedlings don’t need fertilizer right away because they get their first food from the seed itself. After the 2nd/3rd sets of leaves they’ve depleted their own food so they do need feeding at that point. But it’s also easy to overfeed plants that are so small, which can also cause damage, burning, or death. I had used a soil-less mix especially made for starting seeds indoors. I knew it didn’t have fertilizer in it, and had read that very diluted fish emulsion is especially good for tiny plants. I think I added 2-3 teaspoons to a gallon of water and used that to bottom-water the plants every time they needed water, which was just about every day.

Growing plants indoors can be simple, and done on a very small scale. Or it can be very complicated, and on a large scale. I had planned on 100 transplants the first time, (because that’s how many transplants I’d been buying at the garden center each year). But in my first effort I had about 300 transplants, (because I tend to go overboard). The next year I had about 700. I gave the extras to the neighbors. Yes, it was all amazingly complicated, but lots of fun.

I was trying to find a picture that looks similar to my light setup.
Here’s a site with showing a light hanging over a table, (scroll down to the 3rd picture). It looks somewhat like mine, except I had four times more. I also didn’t use a reflector screen or heating cable.

And here’s a site with good information on indoor plant lights, with also a mention that inexpensive fluorescent bulbs are just fine.
That picture of the tiered stand is what I really wanted. I even bought the materials to build a wooden one, (and it’s still waiting in a corner of the basement). I ended up using just a table in the basement, which worked just fine too.

The basic logic of fertilizing these small plants at the early stage is to give them a good start in life. That early feeding makes them vigorous, robust, sturdy, and able to survive hardening off, and the shock of transplanting into the garden. And the early feeding also makes them better equipped to shrug off disease. The fruit comes long after they get transplanted in the garden, many weeks later. By then they will be getting their nutrients from the garden soil, which you might also want to fertilize. It really depends on the condition of your soil. I used compost myself, and worm castings from a friend’s worm bin. I used the rest of the fish emulsion for houseplants. But if you want to use it out in the garden it’s probably good that way too.

Good garden soil with lots of nutrients will look dark and crumbly. If you see lots of worms that’s also a good sign. But if your soil looks dry and lifeless, sandy, light-colored, or very hard and dense, like clay, I’d recommend using compost to help “condition” the soil. Compost improves the soil’s texture to something that’s suitable for plants, and it also feeds the soil, and the plants.

To add to raindrop’s good advice and summarize what I do with seedlings started indoors:

If you use a plastic dome to start seeds, the best kind is one available at many garden centers and hydroponics places. It has adjustable vents which can be opened after the seeds sprout, to gradually lower humidity levels. Even indoors, young seedlings are susceptible to shock if there’s a marked sudden reduction in humidity. If you don’t have vents, gradually loosen the dome coverage over a few days after sprouting.

The keys to best seedling health indoors are strong light and cool temperatures once the seedlings are up. Don’t even think about hardening off outdoors until you have young plants with several sets of leaves, and it’s maybe a couple weeks or so until the average last frost. Initially I put young plants out in a bright but shaded location, shielded from wind (a cold frame is good), then gradually over a period of a week or more on average, expose them to more sun and wind.

Here I’m starting some ornamental pepper seeds today and expect to have them hardening off outdoors in a month or so, then in the ground a week to ten days after that. I just transplanted some canna and Oenothera (evening primrose/sundrops) seedlings to community pots, and depending on whether it stays mild here (minimum of sixties during the day and above 40 at night) they could be out in the coldframe within a week).

Having gardened in Texas, I know that outdoor life for young plants can be difficult, even past the last frost date (bright sun, wind, heavy rain, armadillos, Republicans etc.).

You can hope for the best with your spotted/shocked pepper seedlings, but typically plants that are severely checked in a very young stage will either take awhile to recover and grow, or even remain permanently stunted. If they don’t show vigorous growth in a week or two, I’d toss them out.

Good luck.

Yes, they indeed make for very good aphrodisiacs.

Yeah… I am a total gardening noob. I had just sort of assumed that plants is plants, and they all love sun and such, so what’s the problem? The entirety of my growing experience consists of starting some bean plant in first grade by putting it in a ziplock bag wrapped in a moist paper towel. At the very least, I’ll know enough to do this right if my first crop fails.

Thanks, I’ll look into that. Luckily enough the season is still early enough that even if I have to start over again from scratch, I should be able to do it right and still get a crop that will yield at least one batch of peppers before the end of the warm months, in November or so.

I also am not able to plant directly into the ground as we’re currently renting a house and aren’t able to rip up any of the back lawn, but I’ll take your advice for the container-based growing that I plan on.

Ah, thanks… I’ve already had it off since the other day when I posted, and some of the plants seem to be doing fine. I will wait to harden them off until they’re a good bit more mature though. As for sunlight and wind, is a coldframe necessary? The roof of the house naturally provides shade for the back porch once the sun is a little bit past noon. Hrm, maybe I can find a coldframe somewhere on the cheap.

Thanks, I already tossed a few Jiffy Pots that had seedlings which had withered or died, but those I have left seem to be doing really well (including one that was doing so well that evidence one of my cats figured it’d be a good idea to bite its top off). I have five or six mucho nacho plants that are still green and free of yellow spots and which have perked right up over the last day or so. I’m not sure about the mild and standard jalapeno plants I have, but one or two of those may survive as well, which should be fine as that many plants will take up quite a lot of container space in our back yard anyways.

I leave the peppers out until the leaves start to get limp around the edges. I bring them back in and put them back under the lights. In a couple hours the leaves are back to normal. I put them out a couple times a day, until they can stay outside the whole day. Wind is your enemy if your starting to harden off plants. You need to have a windbreak. Remember to only put them outside when it’s warm out. A 45F day is too cold.

Thanks. I’ll figure out a good way to set up a windbreak. I’ve also read that a gentle fan on them indoors can help toughen them up for life outside, any opinion on that?

Meanwhile, I’m in Texas. A 45 degree day would probably indicate the coming apocalypse right now :wink:

I had been thinking of the fan idea, but didn’t think it was worth mentioning, (besides didn’t I write a lot already?). I didn’t use a fan and had great success. I just think of a fan as one of those things that can help a bit, but certainly not critical to success.

Jiffy pots got tossed? Are they the ones made of peat? You could chop them up, put them into the garden soil to help condition the soil. But if I were very concerned about disease I’d compost them first.

You’ll be gardening in containers? Sorry, I had assumed you’d be transplanting into the ground. But container gardening is quite different, and needs other considerations than regular planting. Be sure to use a soil especially formulated for container gardening, because the other kinds won’t work well at all. I once bought soil for container gardening and I’m sure the bags must have been mislabeled. I had to amend a lot (using peat moss, sand, etc) in order to make it appropriate for containers. Containers also dry out quickly and will need to be watered very attentively, maybe daily, maybe more than once a day. There are also special water-retaining pellets for use in containers. Or the potting mix you buy might already have those in the bag.

Thanks. I’ll swing by the local nursery (or wallmark whichever) and try to find the right soil.