missanja
Newly Registered
Posts: 1
Joined: Tue Feb 02, 2021 1:52 pm
Location: WI, Zone 5a

Advice requested for starting seeds in unheated sunroom

Hello gardeners,

I am new here and love all the threads I have looked at so far.

I am in Zone 5a, so pretty darn cold right now. This is my second season growing in this zone, I am used to warmer climates. Last year I bought starts and also direct seeded. This year I'd like to start seeds in my unheated sunroom but feeling unsure on how to best proceed or if it is even a good idea.

I need to get a thermometer so see how much colder the sunroom is than outside. I do have my potted herbs in there (rosemary, thyme, oregano, mint) and so far they are okay even with outside temperatures dipping to the single digits.

I'd like to use the sun room to start seeds because of how much light it gets. It is south facing with east and west windows also. However, It is not well insulated and the windows are single pane. When the sun is shining it can warm up the room quickly though. I am in a rental so modification possibilities are limited.
Sunroom.jpg
I was thinking heat mats for germination but since germination does not require as much light I could do that part in my apartment and then transfer to sunroom once germinated. For increasing the air temperature I have been playing around with the idea of simple brooder type heat lamps but am worried I may fry my plants if I do not get the distance right and also about the fire hazard of having them on at night.

Premier 1 has these carbon fire heat lamps that are meant to be hung high and have some safety features for automatically turning themselves off it it gets too hot. https://www.premier1supplies.com/p/carb ... ria=heater

The room is only 7 x 14.

A greenhouse style heater with a fan is another idea but I am concerned about electricity costs. I could use a heater with a plug in thermostat to keep the temperature within a reasonable range. I do not need a tropical oasis just warm enough.

I'd like to start onions soon but this week we are projected to get at cold as -14F at night. Seems best to wait on those. I'll get a thermometer and report back.

Any advice appreciated.

Kindly,
Anja

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digitS'
Super Green Thumb
Posts: 3925
Joined: Sun Sep 26, 2010 1:10 pm
Location: ID/WA! border

I will be starting onion seed soon in the greenhouse (sunshed). The heat will not be turned on in there for about 6 weeks. So, unlike seedlings started in the kitchen and first moved to a South Window, the flats of onions are somewhat on their own.

On their own except I don't want the soil to freeze. They will be moved to the floor of the greenhouse and covered with plastic if there is any danger of that. Being home most of the time makes it easier to be conscientious however, the onions' environment will be mostly quite chilly. This is also zone 5 and onions are about the toughest seedlings I grow.

Both January 2020 and 2021 have been unusually warm. Autumn was something of the opposite. I don't think that I should assume that late winter will be anything but normal so I'll maintain the usual. Long-term guidance from the Weather Service suggests a little below average temperatures here.

I don't have good suggestions regarding a sunroom beyond keeping a journal with information on temperatures and your assessments. Gardens are usually made up of a real variety of different plants with different "best practices." Diversity is very important in gardening and we just have to try for some normalcy realizing that, once outdoors, variable will be the standard. This is the important reason for diversity ;).

My garden plants are started in the kitchen in high locations, as an attempt to keep them above 70°f. I will continue to turn the house thermostat down to near 60°, at night. As soon as the seedlings emerge, they will have to go to the South Window. Overnight, even cloudy daytimes, are somewhat cooler there than other rooms in the house. That's okay. I'm not trying to push their growth. Temperatures should somewhat match the amount of sunlight that reaches them and this is a fairly cloudy springtime area.

I have, at times, had supplemental lighting but it is such a bother to set it up and move later that it has not been a standard. The broad variety of different species of plants is, again, a limiting factor for best practices.

Once they are moved to the greenhouse, the plants will have more light but I won't be trying to "push" them with higher heat. They are tender things. "Hardening-off" will come soon enough. Throughout, I'm trying to pamper the seedlings. Hardening-off is somewhat of a silly process in my backyard but they will be as tough as I can get them by the time they make it out to take up their garden lives and circumstances ;).

Steve



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