I was wondering, is it a good practice to pinch out new growth on most winter and direct sown annual and perennial seedlings to promote a bushier plant? I find some of my WS annuals to be a bit lanky. Thanks
If you are finding the plants are a bit lanky, and you are growing them in the right amount of sun, then pinching sure can help. This works only for plants that actually produce a stem, of course. Something that only shows leaves above the ground cannot be pinched. If these leaves are small, on long petioles or in other ways showing they want more light, then the only way to make them dense is to grow them in a brighter location.
Diane is right about depending on the type of plant you are finding to be leggy or taller but not enough side shoots.
I find the best time to pinch out seedlings is when they are about2-3 inches tall and only IF they are meant to grow side shoots, so things like Fuchsia, Geraniums, both bush and hanging / trailing, there are many plants that require this type of help to get them to form tight but bushy plants and you really would need to read up each type of plant you grow but the sooner they get pinched out the better as IF you wait too late, you dont get flowers till way into the flowering season and by then, most new gardeners are loathed to remove the growing tip because they just want a flower instead of a bunch of flowers per plant.
Diane has also hit on the light the plants are receiving and this might be a problem at germination time, seeds dont need strong hot sun to germinate but they do require good LIGHT otherwise they start to stretch upwards ?tall just to try reach better light so I try every few days to rotate my trays of seedlings so the one side of the try / Pots dont get constant light and the furthest away side gets very little, by rotating the pots / trays the seeds get an even amout of light and they wont topple over either once they are too tal.
Outside direct sewing is the same, make sure there is no shade reaching one side or the seedlings and bright on the other, I no longer do direct sewing for that reason due to our weather here, darkness for longer in day time.
I use seed trays or individual pots (small) and sew, place these in a better situation but sheltered from cold or wind, and transfer the seedlings when large enough to handle.
Hope this helps you out a little along with Diane's help too.
Good luck and best regards. WeeNel.