Planting Coriander Seeds

Coriander is easy to grow on a windowsill. And now is a good time to plant it so that it has time to mature before June. Although it will grow all year round from seed, it tends to be difficult to grow in the summer, as it runs to seed itself very easily during the hotter months.

I am using 200ml clear plastic drinking cups. These have several advantages for growing seeds, especially for coriander, where small plantings can be made at weekly intervals (or whatever interval is most suitable) throughout the year without taking up too much space. Using these cups is also an ideal way to learn how to grow, since we can see exactly (well, ALMOST exactly) what is happening beneath the surface of the compost, and we can have a better idea of what watering is all about. I outlined the benefits last March in 'Seeds in a Cup - Background'.

THE TECHNIQUE

The technique used to grow basil last year, outlined in 'Growing On A Windowsill', was successful for coriander (though, unfortunately, not for the basil). I am using it again here with slight modification.

An awl is a good tool to puncture the cup as near to the base as possible, so that the hole is visible and is not actually beneath the cup (where it would be blocked). It doesn't have to be too large, since - contrary to rhetoric - water will drain quite quickly even from the tiniest hole (smaller holes are also good for outside use, since they prevent slugs and other pests getting into the pots - just thought I'd mention that)

Use about 20 seeds and press them, evenly spaced, into the compost as far as you can without compressing it too much. Don't forget to place one or two at the edge so you can see the roots growing down the side of the cup.

You don't need to cover the seeds with dry compost. What I do is cover them for about a day or two with clingfilm. But I make sure that there is a hole in this film to prevent excessive humidity. Drops of water on the film first thing in the morning is O.K.

Place in a south-facing shallow windowsill in good light (direct sunlight is O.K. but watch for excessive drying and heating). This should keep the cup about 18 to 20 deg C (64 to 68 deg F) - you don't need to be too fussy. It is good if the surface of the compost dries a little, since this will draw air in and help avoid disease, but make sure seeds themselves remain at least partly damp. If you scratch the surface of the compost, it should be damp just beneath the surface. Spray with water if necessary. Otherwise, after 3 or 4 days, the seeds should be moist enough (they turn darker in colour) and spraying should not be necessary.

You should see the seed cases bursting open after 4 or 5 days.

If you haven't got a south-facing windowsill, start seeds off in a warm spot, but place cup in a cooler spot (about 15 to 16 deg C) once they start germinating.

Watering should not be necessary for a couple of weeks.

Click here to see last year's coriander posts.