Understand that the “official” or “original” or “real” way of wintersown involves starting seed OUTDOORS in “taped closed” jugs (with the cap off for ventilation). They get the proper light and because of the somewhat protected environment, get off to a earlier start (germinate sooner) than they would if they were sown in borders or gardens without the protection of the container.
The seed of certain plants can be sown in these jugs (or other various containers) and go through extreme low temperatures, germinate, and still go through freezing and thawing cycles many times without harm. The seed will know when it’s safe to come up. That’s how this kind of seed/plant was designed.
Here are a few characteristics to look for that will give you an idea as to whether or not the seed will be successful when subjected to freezing and thawing after germination.
The seed of plants that:
- need a period of prechilling before they’ll germinate (like snapdragons)
- self sow in nature (your borders or garden)
- come up by themselves in the spring
- are sown by nature (or seed packet instructions) in mid to late summer
- are sown (by seed packet instructions) before the last frost, like many wildflowers.
Growing Seedlings Inside
If you grow seedlings inside for any length of time, other than to allow them to germinate, you have to have sufficient artificial light. Thus, you need a place for whatever jugs or flats you use, plus a set up of lights to be kept only an inch away from the seedlings. (You don’t need grow lights. Plain fluorescent lights, warm or cool, will do just fine.)
If you’re a regular reader you already know that I don’t have any space to set up a growing system inside my house.
Modifying the WinterSown Method for Vegetable Seeds
Necessity is the mother of invention and sure enough that is how I came up with a way to start seeds using the “idea” of wintersown. But I modified it to adapt to the needs of vegetable seeds and seedlings that may not be hardy enough to take freezing temperatures even with a taped closed jug to act somewhat like a mini greenhouse.
How to Get Started
- Prepare your containers and identify what seed they’ll hold. (See my post You Can Plant in December) Remember to wet the grow mix well before you plant.
- Sow the seed.
- Place the jugs inside (I put mine on top of my washing machine; the top of the refrigerator is also a good place). The temperatures where I keep them runs from 58° to 65 ° F this time of year. A few degrees warmer in a month or so.
- Let the seed germinate.
- Either immediately or at least within a day or so, tape the jugs closed (take the cap off for air circulation) and place outside. They’ll be hardened off immediately which saves a lot of time. If you wait too long, you’ll have to go through the hardening off procedure.
Things You Need to Keep in Mind
To be successful with this adaptation, you have to put your thinking hat on and have some idea of what the plant can tolerate and what it can’t BEFORE you start. (Easy to know if you’ve gardened any length of time or just by doing a minute or two of googling.)
AND the other thing you have to keep in mind when making your decision about what to leave out in colder temperatures is what other variables are involved?
Here’s a few variables to think about:
- Do you want to take a chance of temperatures going lower than predicted?
- Are the containers on the ground or off the ground? The ground holds more heat (if it’s been warm) and can impart that heat to the containers on the ground.
- Some areas outside might be more protected than others. Are your containers in such an area?
- Will it be windy? In cold windy conditions the warm air even in protected areas can be blown away.
- Plants growing in warm conditions that experience a sudden drop in temperature that they usually could take, may not survive because the change is so sudden.
Another Point to Consider: How Old Are the Seedlings?
Newer seedlings are more likely to be damaged by a severe temperature change. Lets take onions for example. Onions can tolerate very low temperatures. Temperatures below 20 they don’t like, but they can make it through.
I have small onion seedlings that I started a month ago or more in jug bottoms without the tops. When the blizzard and very low temperatures were in the forecast, I brought them into my enclosed porch and put them back on top of my washing machine during that cold week. I’ve lost small onion seedlings that way before when only about 10% made it through. I didn’t want to lose these so I brought them in.
The day I put them outside again was really warm, but that evening was in the 20s. I bundled a large piece of row cover fabric and placed gently over the onions under the cold frame. Took it off the next day. Probably won’t be severe enough to be needed again.
Warm Weather Crops
In general ALL warm weather crops such as melons, cucumbers, tomatoes, potatoes, peppers, eggplant, corn, squash and beans will be KILLED when temperatures drop to 32°F and below. There are always exceptions especially with well established older plants, but don’t take a chance on leaving young seedlings of these plants out in an expected frost/or freeze.
When I start warm weather crops and then put them outside, they’re in a taped up jug until daytime temperatures stay above 50°F. If temperatures fall below about 38° I put them under a cold frame for even more protection just to be on the safe side.
TIP: Don’t start warm weather crops too early. I start thinking about it in March and look over the forecast. If temperatures are warm I’ll start seed in mid March. If temperatures stay cold, I wait until the end of March or the first of April.
Various Notations on Cool Weather Crops
The cool weather crops I started in January are lettuce and onions. I’ll be in full swing the first week of February and will sow beets, radishes, chard, spinach, and several other things.
Below, I’ve noted a few vegetables that thrive in the cold BUT keep in mind as you read that variables will have a lot to do with what happens and nothing is written in stone. What I’ve noted is what is generally true.
Broccoli, cabbage, kale, peas, spinach and turnips can take a lot of cold.
Brussel Sprouts do very well in the cold. I have two experimental plants in the garden right now. Both have some degree of protection; one more than the other. The one I could get to looked great after the blizzard. I can hardly wait to see how the larger one faired.
As Ray (friend and reader from Canada) mentioned in a comment to the last post, he has lettuce and beets that look great through the plastic of the tunnels. He can’t get into his tunnels until some of the ice and snow melts. That’s my situation as well.
Kale, carrots, parsley, and peas do well most of the time.
Leeks and spinach are extremely hardy.
Broccoli, cabbage, cauliflower, chard, lettuce, radishes and turnips can do well to about 28 degrees (some lower) – depending on existing variables. Even if they suffer leaf burn at 28 degrees they may still make a comeback.
Lettuce is influenced by variety as well as temperatures. Sierra Batavia, one of my top favorites, does not like the cold at all. It protests by declining in vigor immediately at the first 32° F night. In order to have good lettuce all through cold winters (under protection) you need to have a variety like Winter Density that does well in cold weather.
With the information I’ve given you and a little thought, you can be very successful growing from seed without any indoor setup.
If you do lose something, just consider it a lesson learned and keep going forward. You’ll do very well.
Addendum – PICTURES – After reading Frank’s comment, I thought it would be helpful to clarify with a picture showing how I cut the jugs. Although you can cut the top off completely and then tape it back, it’s easier if you don’t cut it completely off. Leave about an inch connected to act as a hinge, as I’ve indicated in the picture.
Also I’ve shown some onion seedlings that should have gone outside two or three days ago. Although it’s warm today (60 degrees) – it’s very windy, so I’ll put them under the cold frame for some protection until they adjust.
Hope you’ll find these pictures helpful.
All content including photos are copyrighted by TendingMyGarden.com. All Rights Reserved.