Grow house temps?

[Bushman]

Just a quick question.
I have my seeds inside my indoor grow house. A shelf wrapped in plastic with 4 ft lights inside.

2 of the 72 cell trays and a 36 cell tray are now filled with seeds.
I have a electric heater on the floor under the shelves that keeps it around 80 degrees in there the entire time.

I planted Saturday and this is tuesday eve. So far my sprouts are broccoli, cucumber and tomatoes.

I have pulled off the domes on the seedlings. Should I keep the heat at 80?

I hope to have them in the garden by the second weekend in may.

[digitS']

I don't know much about growing under lights even tho' I was working at a greenhouse when they put an acre of ground under supplemental lighting.

My own plant starts are all out in my backyard greenhouse right now. Without lights.

Here is what I understand about light & heat: they go together. There is a correlation between plant growth and light/heat. If you have adequate light, you can give your plants more heat and plant growth will be more rapid.

If you do not have adequate light to match warmer-than-usual conditions -- turn your thermostat down.

Too much heat with inadequate light makes for weak growth - bad idea. You can have nice plants without much light if they grow at cool temperatures. Of course, they won't grow very quickly if it is, say, 60°F. All of this varies with plant species.

Still, lots of commercial greenhouses will run between 60° overnight and 64° during cloudy daytime. Supplemental light allow greenhouses to go to warmer temperatures. (This was a result of living where hydro-electric power was cheap and "surviving" the oil embargo of 1973 and having cheap energy restored . . . I'm not saying that any of this was a good thing .)

Steve

[applestar]

Take temp reading on each shelf. Since heat rises, it should be warmest up top and coolest near the bottom. I would put the heater on the second shelf up or something and create cooler growing shelves too. On the other hand, the heat source being at the bottom may make some difference -- maybe it's cooler up top or can be made cooler up top with ventilation.... Another option maybe to add a shelf unit NEXT to the main one?

All seedlings grow stronger/sturdier at much cooler amibient temperatures than when they are blooming/fruiting, and remember you are going to throw them outside where it's going to be much colder later on as well and they will need to be acclimated.

Now broccoli sprouts in no time at all 2-4 days with 80° soil temp, but they don't like it that hot once they start growing. *Maybe* 70-75° until first true leaves but even that might be too much.

Broccoli seedlings should be grown coolest around 45-60°, tomato seedlings should be around 55-70°, cucumbers (a little early -- should have waited another couple of weeks) around 65-80°F.

[IndyGerdener]

Personally I keep my grow shelf around 80 all the time. Then when the plants get big enough I put them out in the greenhouse. This works well. I have had no problem with any plant sitting at 80. I do have my heater at one end under my growing shelf. it is cooler at the top shelf and cooler yet at the far end 5' away from the heating source. I try to set it up so all my propagation and sprouting happens on the hotter side and then gradually they are moved toward the cooler side before going out to the greenhouse. My greenhouse then ranges from 40 at night to over 100 in the day.. I was concerned about the temp swing, but the plants I have out there have thrived and are flourishing!!!

I am adding a window to my door set to open automatically at 80. This should keep the greenhouse out of the 100s

[applestar]

Tell us what kind of plants you have had success at 80° temp and what stage you consider "big enough." I will add to my notes.

[IndyGerdener]

Tell us what kind of plants you have had success at 80° temp

Ghost Peppers


Jalapeno Peppers, Cayanne Peppers (You know all the peppers I grow), Indigo Apple Tomatoes, Amish Paste Tomatoes, Peas, Green Beans, Shell Flowers, Asparagus Fern, Cilantro, Basil, Parsley.. Just to name a few things just in this picture You can see in the picture how it is set-up, the heater is under the far right shelf, and that is where I keep my seedlings, and progressively they get more full grown the further away from the heater they are

what stage you consider "big enough." I will add to my notes.

You are not a novice gardener, you know it is a plant by plant thing. I try to wait till I am about ready to up pot them out of the solo cup sized pots. Peppers are about 12", the 2nd time around (I chop them in half the first time they reach 12"). It is like trying to explain your watering schedule.... you just know when they are ready...

[IndyGerdener]

I will try to get a picture of my greenhouse tonight to show the plants that I think are "Big enough"

[applestar]

That would be good.

You are not a novice gardener

No, *I'm* not, but you have a bigger audience when you post.

Also, there are always more things to learn. I think there are more things I *don't* know than things that I do know. Even when a method has worked for me for a long time, I love learning other ways that has worked for other gardeners and comparing the relevant conditions.

[Bushman]

Thanks for the replies.

I built my grow house so the heater would be on the bottom and the only way the heat travels up is on the ends of the shelves. There is a slot about 2-3 inches wide where the heat can filter up and through.
It works as a heat mat because all the warm air is mostly trapped under the thin 1/4" plywood and it heats it up like a heat mat.
My trays are on the first shelf above the heater. A digital thermostat probe laid on the shelf is reading 77-80. Soil temps are right there as well.

The upper shelf has even less of a gap to let the heat through and should be even cooler once I begin to move the plants "upstairs" to that shelf.

When all seeds germinate I will lower the heat a tad. Still would like it around 70 for a few weeks and then slowly lower it to whatever the room temp is which is usually pretty cold.

[IndyGerdener]

https://www.youtube.com/watch?v=A7nk-7jD ... e=youtu.be

In the video you can see some of the set-up and what is moved to where and when.

These are too big for the grow shelf and have been moved to the greenhouse


As are these.



I moved alot more last night. The video shows most of the pepper plants that are living in the greenhouse now

[drh146]

So what temp do you keep yer greenhouse at Indy gerdener

[IndyGerdener]

It stays around 45-50 at night and sees temperatures up to 110 during the day. I have an auto vent opener on order. That should keep it at a 90 degree high during the day

[drh146]

Thanks. And what's thus about chopping the peppers when they get 12 inches? What's that do ? And is it just the main stem 6inches off? Or some side leaves to?

[IndyGerdener]

https://www.helpfulgardener.com/forum/vi ... =4&t=51408

This should explain most of it