Jason Goodwin: How legginess, though desirable on humans, is the devil in seedlings

Our spectator columnist recounts his struggles to grow his seedlings indoors without allowing them to become weak, resorting to dubious lighting methods and not a small amount of fussing.

It’s approved for blondes, of course, but leggy’s the devil in seedlings. It’s almost as bad as damping off.

Two hundred seedlings, in tiny coir pots, are sitting in plastic trays under the dining-room window. I’d studied the seed catalogues through the long winter months, Googled permaculture 20 times and drawn rings around the peas and the lettuces I wanted.

I even got in an early order for agretti, the Italian salad crop my friend Simon grew – well, he did before it became so fashionable and the seed so rare as to be unobtainable. Slightly fleshy like samphire, but shaped like a grass, it’s known as barba di frate, or monk’s beard, in Italian; its English name, saltwort, is a reminder that it grows well by the coast.

Young lathyrus odoratus 'Spencer' variety sweet peas sown in recycled toilet roll inners, growing on a warm windowsill indoors, ready for planting out

Worked into a lather of impatience and expectation, I bought those biodegradable pots, which I may yet regret, and set to work with lettuce, beans, peas and seed compost.

I’ve been consulting an online frost map of England, too, which purports to show, in fantastic detail, the date of the last frosts recorded in our patch over the past few years. I mean to steal a march on the season and get sturdy young plants out in the open ground in early April.

‘The posher lighting arrays can be alarmingly expensive, but, thanks to the stoners, I now know the cheap ones’

Some people mistrust my coir pots, but, indoors, in a waterproof tray, they paddle contentedly in the water I give them. They soak it up without disturbing the seed and the compost darkens agreeably. Roots are snaking towards the source of moisture to break vigorously through the compostable walls of their pots. The trouble now is finding enough light, because seedlings grown in the gloom become leggy and weak.

Three Sprouts With Grow Lamp

I fuss. Every hour or so, I slide the trays around the table in the window to catch the sun, if there is any, and turn the pots towards it. I peer for emerald in the murk and am always thrilled to see another tiny leaf push through towards the light.

The peas, I’m pleased to see, are up first; the little gems are also away. I’ve been unlucky with peas – mice burrow through my vegetable beds and silently remove the seed and pigeons pick off whatever they leave behind.

I even looked into a grow lamp, to prevent that tendency to legginess, and discovered an entertaining online subculture, possibly created by the hapless stoners who use these lights – full spectrum, good for growth – to raise cannabis plants in suburban attics.

The posher lighting arrays can be alarmingly expensive, but, thanks to the stoners, I now know that the cheap ones, to which they and I naturally gravitate, are alarming in their own way. ‘Very poor construction,’ says a one-star review of a lightbulb that fell apart in their hands.

I enjoyed the bitter sideswipe: ‘Would have returned it, but a family member threw it away.’

‘Leggy seedlings or a cardiogram on a Sunday night?’

All these bulbs seem to fall apart. ‘Tried to take it out of the lamp and it fell apart,’ writes another user, adding cheerfully: ‘Still works, but it’s in three pieces now.’ Even the four-star ‘Best in its field’ has a downside: ‘They come apart when you try to unscrew them and I got a really nasty shock from one.’ It’s common enough.

‘Thankfully no burns,’ says the leading bad review, ‘but arms tingling and still in discomfort half an hour later after getting off phone with Amazon due to nature of electric shock being across chest and sensations in chest/arms afterwards phoned up NHS and was advised to go spend my Sunday evening in A&E for an ECG which I did.’

I never bought a grow lamp, but I did gain valuable perspective. Leggy seedlings or a cardiogram on a Sunday night?