Where to germinate and then raise the young seedlings

This post is just relating my experience since the early 70s concerning where I germinate seedlings.

Like many, I started in the basement. Unfortunately, as the number of seedlings grew, so did the odor.

I next went to an attached sunroom. Because of odor, the sliding glass door that connected to the house had to be sealed with caucking and plastic tape. After several seasons I noticed a black mold type problem starting. I had to remove the inside walls, clean everying out, and then put in new walls.

I then moved to shelves in the attached garage. Again, odor started so the door from the garage to the house had to be sealed. Plus, we soon lost the use of having a car inside during the bad winter months (the larger seedlings had to be placed on the floor). Also due to the high humidity mold/rust started on the walls and the inside of the outside garage door.

At this point I should mention that at first I would start germinating seeds soon after thanksgiving. This resulted in having many large potted seedlings by the time it was warm enough to plant outside. I then started moving the “shelling” time back, first to Christmas break (I was a teacher) and then to January. (My experience is that seeds stored in the hips will not germinate.) This year my plan is to start in the middle of February.

I now start the seeds in petri dishes on Bromelaid/water soaked sand in a half sized commercial freezer set to run at its warmest setting (around 50 degrees F.). The freezer has strings of red LEDs in it. This system gave very satifactory germination results last year. The freezer is kept in the garage.

Once a seed germinates, it will be placed in a normal seed tray (watered with 5 ml 3 % drugstore type hydrogen peroxide to every 95 ml of water). The potting soil is a commercial coir - peat moss mixture.

The seed trays will be placed in “4-tier Mini Green Houses” that I have placed against an outside back wall of the house where there are no windows (the units will be facing West). (Our allotment restrictions do not allow permanent separate buildings such as a normal greenhouse.) Essentially these Mini Green Houses are 4 shelf units with each shelf holding 2 standard seedling trays. Each unit comes with a zippered plastic cover. I expect to need three such units. (Thet can be purchased from a number of suppliers on the internet, for example, www.FarmTek.com, item 102445.)

When the seedlings have outgrown the Mini Green House, they will be placed directly into the raised seedlings beds. Initially they will be protected by an opaque plastic gallon milk container which has the bottom cut off.


Awesome post, Henry. I wish I had a basement. I have done previous years work outside starting in March but this year the seeds didnt want to wait. The air cleaner is keeping things clean, though.

I am quckly running out of room in my basement and only have room for 6 flats of seedlings. I am keeping may seeds in cold stratification until mid Feb. I just took them out last weekend. I am hoping that the number of germinations will be low enough to give me some time till it warms enough so I can move them all outside.

I am considering adding some lights to my crawl space. I would love a small green house but its not something I can afford.

Dont have any problem with odor. Smells like damp earth after I water. My rubignosa seedlings are making quite a stink I guess. Of course, I dont have near the number seedlings that you do. I think I ended up with around 30 petri dishes worth of seeds in the fridge this fall.

I wish it would warm up a little bit. I have a Xanthina seedling that is taking up a ton of space under my lights. It was small last fall when it started to freeze so I thought I would keep it under lights all winter. Its gotten rather large since then.

My problem is aphids. They are a persistant menace. They came in with something I brought in from outdoors and have set up shop. I did find a Ladybug crawling around the seedlings a couple of nights ago though.

Henry, I do use the greenhouses you are talking about. A few comments.

1 The greenhouses heat up during the day when there is sun, but do not have a flap to release the heat, so you might need to fashion one if they heat up too much. In your climate that might not be a problem, but it is here. Short of that, the plastic is so thin that it will split by itself near the zipper pretty quickly creating it’s own opening for release of heat. Actually that works pretty well, since mine split near the top of the zipper.

2 The greenhouses do not hold the heat in at night. I thought about running christmas lights into the bottom to provide a little warmth. That should work. I haven’t done it because we’ve had few nights that went below 38 this winter so it’s not been needed.

  1. The greenhouses must be anchored well into the ground or they will blow over in a stiff wind. I used strong 15" iron stakes hammered into the ground on a diagonal and secured all four sides. That’s worked well even in 45 mph winds.

I have had to turn to using a 16’ X 20’ greenhouse. There was no other practical way to raise up to 5000 seedlings a year.


Judith, thanks for sharing your experiences.

I have already had 1 zipper break. I plan on replacing with velcro (safety pins are being used now).

I have a 2 thermostat heating cable setup. The first (home made using a commercial 110 volt thermostat) turns on below about 35-40 degrees. The second type (built into the actual heating cables) turn off at about 70 degrees). The heating cables are of the type designed for seedling growing. I wonder if heating cable to prevent freezing gutters would also work.

For those on a budget and/or with limited space, there is a portable mini walk-in greenhouse that will hold 24 flats. It has a door, vents and window, is 5 1/2’ x 6 1/2’, and only costs $179.95. It’s available at Charlie’s Greenhouse at:



It looks good, Gail, although I’m not sure how useful bottom vents would be in the Tucson blast furnace. Anyone using it?

Judith -

I bought one recently so I don’t know yet how it will do in the heat. There is a window behind the girl’s head in the photo. Right now I have it in separate pieces so that I can have the shelves inside for flats. I’m very happy with it so far.


Gail, let us know how it holds up, especially in the wind. Sounds like a cheap solution.

Do you realize that most greenhouse manufacturers make a kit for a 16 X 20 poly hoop house that costs about 600 to 800 bux? Five years ago I paid only 500 for mine. You have to build your own ends and doors and benches, but its still not that much money and you get a significant greenhouse space.