Weak stems are most annoying. To reduce the effect, I give new seedlings as much light as possible, preferably sunlight and have a gentle airflow from a small fan. Also I only water from the bottom by placing the pots in a larger container of liquid. The pots are allowed to dry out before watering. I don't think hardening off strengthens weak stems.
Here is my 2014 effort. I am reasonably happy so far and have about six weeks to go before planting in the outdoor garden.
http://www.durgan.org/URL/?HGJNN 9 April 2014 Repotting tomatos. Some tomatoes were moved to larger pots. The main reason at this time is to make watering easier.The larger pot holds more moisture and watering times are not so critical.The plants are watered from the bottom by immersing in a container of water. This will be the last move until the plants are placed in the ground at the end of May.Pictures depict the process.
http://www.durgan.org/URL/?YSLUY 29 March 2014 Tomato Seedling Growth
Tomato seedling growth to date.Plants are healthy and growing well.It has been cool and not too sunny since starting even in the greenhouse.
http://www.durgan.org/URL/?DDATG 15 February 2014 Starting Tomato Seeds for 2014
Some tomato seeds were started for the 2014 season in the greenhouse. Selected were Lemon Boy,Bonny Best,Big Beef Hybrid, and Black Krim. Only five plants of each are required. Each seed type was placed in one pot, and will be transplanted into individual pots when they get large enough.The soil was my own home made in the Summer. Each pot was placed in a plastic bag until germination to keep the moisture level high. The pots were placed on a heating mat in the small greenhouse. Some more started on 21 February 2014. All are: Cherokee Purple, Gypsy, Paul Robson, Vorlon, Morado, Black Krim, Bonny Best, Big Beef, Celebrity, Lemon Boy,
http://www.durgan.org/URL/?IEVCS 11 September 2013 Seedling Soil