One of the vegetables I sew begin March was Swiss chard (Virgo). I used normal potting earth and a recycled strawberry tray, and about 10 seeds. Some of them germinated quickly, and became leggy. Not enough light in our amazing large south-orientated window sill with barely 10 hours of daylight this time of the year. I decided to invest in two led grow lights (Nelson 15W), guessing that this could be essential for successful Nordic growing. I can tell now, about three weeks further that it does make a difference. But what started out leggy, remained leggy, and worse : because of the heavy leaves it developed, my poor chard seedlings fell over.
What to do? Pinch them? It was the plan anyhow to pinch off the weaker one from the cluster seed (always 2-3 plants from 1 seed). It feels like murder. What if I bury the stem deeply in the ground, just under the leaves? I know this works for tomatoes (and is even recommended) – they have hairy stems from where they will grow new roots. But with Swiss chard? Would it rot? I will give an update of this experiment once I know the result. The photo below shows how it looked after planting the seedlings deep.
after deep soiling of leggy seedlings
Update: After hardening the plants off for a week, I placed them in the cold frame in the garden. Temperatures during the day was about 6°C (43°F), during the night freezing occasionally until -4°C (25°F). After a week of holidays I checked on them and the result was sad: white spots. Not quite sure what caused it, frost, sunburn, stress ? Drop me a line if you recognize this! I am more inclined to think the last, because the quite frost-tolerant mâche (lamb’s ear) had the same thing on some of the plants. How frost-tolerant is mâche? Well quite a lot: the mâche seeds from fall survived in ground temperatures of -20°C (-4°F) during this winter! (Certainly I will seed mâche next year already in fall for an extra early crop, i.e. May, ;)).
Left: damaged seedling of Swiss chard. Right: damaged mâche seedling
To return to the experiment : I am not sure. The seedlings look miserable, but is because of the sunburn/frost/stress or the deep soiling? The stem is not rotten, so I tend to blame an external cause. But they also look really small for 6 week old seedlings. I would try deep soiling again if the seedlings became leggy, but I would prefer putting more effort in avoiding legginess and prepare a second batch. Drop me a line if you have tried a similar experiment to tell the result; happy to learn from your experience.
I transplanted these miserable seedlings in full ground in the hoop tunnel; will they recover from this damage? If not, the bugs can have them…