Coriander Canary Detects Low Light

All seedlings will etiolate (stretch) if the light intensity is too low. The coriander here is no exception. I have been germinating seeds at room temperature (a cool room), then cooling down to 7 to 8 deg C (44 to 46 deg F) during December (see growing coriander notes).
As you can see from this photo, things were going fine until last week when the mild foggy weather reduced light levels and increased temperatures to 10 deg C (50 deg F). The etiolation (shown above) happened overnight.

This tells me three things:

• coriander will actually grow at low temperatures - far lower than I expected


• most of the winter light is acceptable at these temperatures - it is just the odd fluky day (fog and heat) that can cause problems


• it is still too early to plant most seeds - best wait till the light improves

Because of coriander's tendency to bolt (start forming seeds) during the summer months, if you want just the leaves it is best to plant seeds in small numbers at weekly (depending upon how much you require) intervals. The technique of growing seeds in plastic cups which I introduced last year has proved an ideal way to do this (have a look at the 'seeds' category or read the March 2010 posts).

The etiolated seedlings will still develop and will not be wasted. So it is worth planting a few seeds, just to be sure of adequate light levels.

P.S. I would love to know what fungus is growing on the compost. It doesn't seem to affect the coriander.