seedlings growing too tall and spindly

[eastkentspur]

what causes this and how can i limit it?

could be a light issue but they are on a warm windowsill

[HeyWayne]

Lack of light - leggy seedlings this time of year are common.

Warmth will get them to germinate, light (or lack of) is what makes them grow.

All that's happening is that the plant is searching for light, so grows to find it. Forest canopies are a good example of this working.

Get them onto the brightest (not necessarily the warmest) windowsill you can, and maybe stick some foil onto cardboard and place it behind the plants to maximise the light they get.

[Capsid]

Also, the day length is still short. Sometimes it pays to be patient and sow later in the month.

[Alison]

What are your seedlings, different varieties need different treatment?

[eastkentspur]

worst offenders are herbs such as basil and parsley so i guess it's down to day length being too short at the moment

[Flummery]

Yes, it means you sowed them too early. You can get away with early sowings if you can provide enough light.

[rustylady]

Parsley is pretty hardy, so it can go outside. Basil is not hardy, so you need to provide slightly less warmth now it has germinated, but definitely more light.