For how long can you 'start' seeds indoors prior to spring without lights?

Bit of a newbie question so I assume it belongs here. For how long is a windowsill sufficient for starting a cannabis plant, a week? two weeks? I want to get a head start before spring but I don't want to set up and unpack my 200w LED, I don't have a space for it and I don't have a tent or a room for it currently.

I kind of assume it is sufficient until you top it, past that point, I feel like it will stretch and get lanky, no? Or is any growing time better than no growing time?

Depends on the window. I've seen plants bud in windows with incredible results, but they were in a sunroom. You can easily veg a plant in a large window with a good amount of light.

DankDave420 said:

Depends on the window. I've seen plants bud in windows with incredible results, but they were in a sunroom. You can easily veg a plant in a large window with a good amount of light.

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Tempting me to give it a go. I have a decent 45-degree south-facing window that will get sunlight most of the day on the first floor. Should be enough to last me until spring at least. Thanks for the input

How long are your days?? They will start to flower and reveg with less than 15 hrs..

My 2¢ ….

You can start seedlings under a simple cfl / fluorescent also. That way seedling stretch can be controlled and get more active growth ( 18/6 or 24/0 )
all under your control than just parking on a sill. That way you can ensure they get dedicated lighting instead of “ winging it “.

You don't need a tent for seedlings. Just put the lamp over the seedlings if they stretch excessively.
A tent is required to have continuous dark periods in flower.

You can use a simple energy saving lamp 20w and almost touch the plant with it it would work. But yea depends on the window if you have less than 12h dark and good shine you could in theory bring a plant to flower

Long as the window gets enough light for long enough its fine i start some plants this way mind you i only do it for a couple of days then put it under grow lights it will stretch if the lights not adequate tho and has to be right time of year after the spring solstice for light hours to be right where im at id say two weeks is too long tho unless you stay somewhere nice