How to stop seeds sowed indoors from getting leggy?

[Sue7]

I live in a first floor flat with only a Juliet balcony with very narrow ledge. Therefore after sowing seeds like tomatoes, pumpkins etc indoors, I need to keep them in my flat before they go into my allotment.  What's the best way of stopping them getting too leggy? 

I can gradually harden them off on the balcony ledge but in the past have found that they have become bit leggy before they are ready for that. I don't have access to a cold frame

Appreciate any advice

[Sue7]

[BarriedaleNick]

It is a bit tricky and having access to a cold frame or greenhouse is ideal.
However you can do a couple of things. 
Turn down the temperate if possibe
Introduce a bit of a draft - open the window or or stick a fan on for a bit.
Use foil at the back of seed trays to increase the light and stop them bending too much.
Dont overwater or overfeed.

It is also a difficult start to the season and all our windows sill etc are probably overflowing..

[jimtheworzel]

use tin foil to reflect the light

[Chrispy]

The reflective foil helps a lot. I have foil glued to card held in place by a cheap bookend that the tray sits on, so I can easily remove the reflector for inspection/watering.

Pumpkins do not like being in pots too long and hate being planted out into soil that is too cold, so you may as well wait until it is warm enough for them to be sown outside.

[Bing]

here is an article on how to sow on window sill

I found it on google:http://www.gardenorganic.org.uk/schools_organic_network/leaflets/GrowingOnWindowsill.pdf

[strawberry1]

small pots for pricking out, then deeper up the stem into a slightly bigger pot and again and again. It supports the plant until you can get them properly hardened