Gear necessary for germination

Im having a hard time creating the correct germination environment for veg seeds

I have a soil block maker. I tried making my own seedling soil mix as well as using store bought seedling mix and neither has taken off well.

I've tried in the house as well as in an unheated greenhouse. I do not want to provide heat for the greenhouse (I am attending the 2021 PDC, to learn about the Wofati Greenhouse!). However the temp fluctuations are high. Very hot if the door is closed when the sun is out or cold at night.

Would a cold frame inside the greenhouse stabilize temps?

How to avoid the heat mat?

What other gear might I need to set up a better environment for the seeds?

To stabilize your greenhouse temps (keep from getting too hot) look at automatic vent openers. Hydraulic ones are common. No power needed, the fluid in the opener reacts to temperature.

A lot of seeds simply require heat to germinate and there's no getting around that, so perhaps consider doing just the germinating phase indoors where you have power or at least a warm room. Then move to the greenhouse.

Bobby Fallon wrote:

I've tried in the house as well as in an unheated greenhouse. I do not want to provide heat for the greenhouse

temp fluctuations are high. Very hot if the door is closed when the sun is out or cold at night.

Would a cold frame inside the greenhouse stabilize temps?

How to avoid the heat mat?

What other gear might I need to set up a better environment for the seeds?

No, a cold frame is just a small greenhouse, and putting a greenhouse inside a greenhouse isn’t going to help. “Control” is what you need.

A greenhouse is a structure with walls and roof made chiefly of transparent material, in which plants requiring regulated climatic conditions are grown.

Greenhouses don’t regulate themselves without the technology to do so (thermostats, artificial heat, cooling, automatic vents, humidity controls, fans, grow lights, etc.) that environment is constantly changing and plants have to stay well within their Goldilocks zones the vast majority of time (no big fluctuations, you gotta tame it). Seeds also have a Goldilocks zone for germination. For most veggie seeds it’s about 77 degrees with 100% humidity. (I don’t keep my house that hot).

http://sacmg.ucanr.edu/files/164220.pdf

Give that a gander.

If you want plants to germinate or grow (when nature doesn’t want them to), then you have to control the environment and trick the plant. It’s often easier said than done and any greenhouse requires constant modifications (any time there are plants inside).

The heat pad is easy, people like easy, seeds like it too. Young plants are delicate and once they sprout, they are still going to need to be kept alive, a properly run greenhouse is the best option for that and books and classes are the best way to learn all about that fickle tool.

Good Luck!

Bobby Fallon wrote:Im having a hard time creating the correct germination environment for veg seeds

The best environment for germinating seeds for me is a Ziploc bag, paper towel, and a spray bottle filled w/water and 1tbs hydrogen peroxide. If they're very large seeds then I just soak them overnight. In the morning, I spread them out on a paper towel covered plate and cover with a bag to keep moist.

I find a seedling heat mat to be invaluable. I germinate my seeds in my solar building, which is just a garage that houses our solar equipment, with heat mats and lights. After germination, the seedlings are moved from the heating mat, to just under lights in this building, then I up-pot good seedlings and transfer to my unheated greenhouse. To regulate temperatures in my hoop house style greenhouse, I added both automatic vent openers, and additional doors covered with hardware cloth, and barrels of water for thermal mass. The automatic vent openers don't provide enough ventilation for my climate so I added the doors. I tried all kinds of different ways to start seeds, but nothing compares with the heat mats. We are off-grid and find the additional power for them to be negligible.

Yes a cold frame inside the greenhouse will help mitigate the cold at night, it's quite common to see a clear tent set up inside a larger greenhouse to help tender plants. However it won't make it any cooler in the sun.

Which seeds are you trying to germinate? lettuce seeds won't germinate well if you get the soil hot enough to germinate peppers.

However if you are having problems in the house then temperature probably isn't the issue unless you keep your house very cold. If you can give them a temperature of around 20C (68F) then most things will germinate, (peppers will take a while at that temperature) I keep all of mine on some shelving (actually an old wardrobe turned on it's side.) under lights, I don't turn the lights on until they germinate. If I am trying to force something to come up fast or something wants a higher temperature I can either turn the lights on early, but then things dry up or my preferred choice is to put them on the bathroom floor which is heated, soil on that floor keeps around 26C (79F)

Other things to check are the seeds themselves, do they germinate if you put some on a  piece of wet cloth and seal it up so it doesn't dry out? Then I would look at the rest of the conditions, are they drying out to early? Or are they getting so wet that they are rotting in cold soil before they germinate?