Greenhouse or inside grow lights to start seedlings?

[TomatoDon]

In the past I grew a lot of seedlings under grow lights inside my house. They always did well. I think back over pictures of them, planted in January and February, and how lush and healthy they looked even in that early part of the year. I don't remember any trouble in actually growing them, and them always being the picture of health.

This year I put in a small greenhouse (12 x 16) and my seedling efforts have been dismal at best. I thought the natural sunlight would be better for the plants, but I'm not sure I believe that now. Also, the temp fluctuations have been so extreme, that the seedlings that sprout seem to get shocked and get to 3-4 inches tall and just stop growing. I would rank this year's greenhouse-for-seedlings as close to a total failure as it gets.

I'm going to abandon my greenhouse for seedlings project and start growing inside my house again under stable and moderate temps with grow lights. I wanted to ask others here there experiences in trying to grow seedlings in a relatively small greenhouse, and also success stories about growing inside under lights and what are the recommended fixtures and light sources used today. I haven't grown under lights in probably 10 years and I still have what I believe was called full spectrum grow lights. They are fluorescent tubes.

Thanks, and I look forward to your replies.
Don

[KarenO]

https://m.facebook.com/NorthernGardenerCanada/
I start in the house for convenience and stable temperatures for germination and move my seedlings out to my small greenhouse once potted up.
Moderating the temperature is quite possible in a smaller greenhouse and the natural light is much better than any artificial light available.
Takes practice and each greenhouse is different. Start by buying a weather station with a remote sensor and monitor your greenhouse temperature. Practice on tolerant plants such as easy annuals, greens, brassicas then progress to more sensitive plants.
KarenO

[TomatoDon]

I'm doing tomatoes only. When the night temps are 30, the greenhouse may stay at 40. Three days later when it warms up and the day time temp gets to 65 degrees, the greenhouse temp might jump to 100. There is a huge swing in temps and opening the doors only cools it partially. It would not be possible for me to keep it within 10-15 degrees of the same temp day and night without spending so much money on heating and cooling and thermostats and other things that it wouldn't be worth it. In that case, I might as well take the seeds to a large climate controlled commercial greenhouse and let them grow them for me. The other option, which may be the best, is to just install skylights in the room where I plan to grow the seedlings. That way I'd have the moderate and even temps of the inside of my house and the real sunlight, too.

[bower]

The steady temps indoors are definitely a plus. Just getting ready to harden off six week old seedlings, but really hard to find the perfect day for that , moderate enough. I dont have climate control either so greenhouse days can be too hot or too cold, nights too cold.
Indoors I find fluorescent tubes good for tomato seedlings but I do also hang them in a window so there is some natural light as well. The window gives some cold exposure at night too, which is good.

[KarenO]

It can be done. Myself and a 25$ space heater are the “climate control” in my Greenhouse
But it takes work and frequent monitoring. My greenhouse is not in full sun and siting and the use of shade is a factor that can be modified to help control overheating which as you point out is actually often a bigger problem in a greenhouse than cold. Roof vents help a great deal as does a small fan.
Tomato Seedlings are easy to raise in the house so just carry on indoors if that’s the only thing you want to grow. Have a great season!
KarenO

[TomatoDon]

Thanks Bower and Karen. I think the simple solution is to go back to my old way of growing but starting seeds under lights. My growing shelves were by the window anyway, so the plants got some natural sun. If I add a sky light, that should be plenty.

[AlittleSalt]

Don, I thought of building a greenhouse, but after a lot of thought, I chose to start my tomato seedlings in our house. After all, I'm paying to keep the temperature around 74F in the house anyway. I do take my plants outside on warm days. It can add up to a lot of moving plants inside and out, but it works for me.

[Lindalana]

Umm, I have a hoop house and only move plants in and out during this time. A bit later when nights temps stay more above 40F plants would move there permanently. Planning to move most of the seedlings next week. I do start under lights indoor then move to what my hubby calls Florida porch with lights and 3 large wall windows. Kinda PITA but space is premium and I grow lots of seedlings...

[ddsack]

I'm one who gets my plants out of the house as soon as possible.
I carry my seedling trays out to my 8'x16' greenhouse just as soon as I can after they germinate, but I don't leave them out at night or when cloudy cold weather can't keep it above 55F inside the greenhouse. I have much colder weather to deal with than you do in MS, so night heating for me is not efficient until the night temps stay above 25F. We had a low of about 8F last week, and projected down to 18-19F at night in the next few days.

The key as Karen said, is monitoring for temperature. I have two remote thermometers (don't trust just one) in my living room that I glance at every time I walk by. My greenhouse is about 100 ft from the house, so I walk out to adjust ventilation as needed. I have automatic roof vents, but in full sun, those are not enough and I have a whole array of various sized wooden blocks and bungee cords to keep my double dutch doors open at various angles depending on outside temperature and wind. Even with outside temps in the 30'sF inside temps get into the mid 90's if it's sunny and the doors are shut. I realize that people who have jobs and are not home all day would have trouble with this amount of tweaking.

I much prefer the health and sturdiness of having my seedlings in natural sunlight, even if it's more work for me. But my light fixtures are old fluorescents, they only run a few weeks each year and I don't plan on replacing them because of their short window of use.

You should do whatever feels best for your situation. No sense in changing what works for you. There is no one correct way to so any of this!

[oakley]

I have had a small sturdy greenhouse for maybe 5yrs that I though would help my Spring real estate issues
but I can't babysit/monitor it like it needs. It holds soils and tools and buckets and the
lawn mower, etc. We had snow flurries yesterday morning and will see high 70's tomorrow...
Spring is unpredictable and wet cold overcast, then boom, summer heat and maybe a late
frost....
It was worth knowing it is useless for seedlings and useful for maybe a week or two....and
storage. Keeps potting up tidy and crap out of the garage.

If I did not have one, I would want one.
Lesons learned not such a bad thing.

[biscuitridge]

I find that my greenhouse works good,I place the seedlings on a thermostatically controlled heat mats,if it drops down cold at night the roots at least stay warm,also if the sun comes out ,the evaporation cooler turns on,in that way they grow good all summer long.

[biscuitridge]

COB diy lights work beautifully for starting seeds,plus they're dimmable which comes in handy at times,and much cheaper to run.

[Harry Cabluck]

TomatoDon: You might want to say how many tomato seeds you start, if you have utilities/gas/electricity in the greenhouse. If only a dozen or two plants, then inside under lights is probably best. If more plants, then why not take advantage of your new greenhouse?

[TomatoDon]

I am utilizing it. Right now the thermometer is showing 105 with the doors open. Tonight it might be 40. It's too much stress on the plants.

[greenthumbomaha]

I have a huge case of greenhouse envy. Most newer subdivisions don't permit structures such as sheds or greenhouses. Older areas of the city and of course country acreages don't have these restrictions, but I am a ultimately a creature of comfort and love my local groceries and restaurants.

This year Omaha had a rare warm 50's week in Feb. I started a small group of plants early indoors with the intention of taking them straight outside after germination in the warmer than usual weather. It was an enlightening experience for a northern grower. The leaves were larger, the plants stockier, just green and happy. I carried them out in late morning when it warmed and brought them back inside in late afternoon for the few precious warm days. I'd never been able to take plants out early, and it was fun to emulate the way southerners grow their seedlings.

I can't speak to your cold nights. It would be too cold here. I use 2-3 year old T5's, and there are better bulbs, but what I have will suffice at his time. Why not do a set outdoors and a few controls indoors.

- Lisa