Saturday, 24 January 2009

Lettuce begin…

The heat of the afternoon has passed on the only day in weeks that was forecast to have maximum temperatures below 30° C, and fronting a week where forecasts predict three days running at 41° C and the rest of them no lower than 35° C. So, at last, it’s lettuce-planting time!
Having seedlings survive and thrive under these conditions, and especially when water is scarce, takes some planning. Yet the bulk of our summer salads rely on a steady supply of at least two large lettuces per day, month in and month out, so postponing planting is no longer an option as our spring-planted lettuces run out, go to seed or are fed to the chooks. We can flush out our salads with rocket, capsicum, onions, tomatoes and other herbs, but the numbers remain the same; there needs to be at least a hundred lettuces planted out into the garden every few months if chooks and humans are to get their greens.
Fortunately, lettuces are dead-easy to grow, provided one avoids the ‘Iceberg’ horrors found in the local supermarket and one stays with the open-leaf types that neither rot under irrigation nor get eaten out from the inside by earwigs. Lettuce seed saving is also easy, and the seeds remain viable for years – mine are at least three years old, and have been stored in a hot shed throughout that time. I keep a working tin full of ‘mixed lettuce seeds’ – these include purple oak-leaf, royal oak-leaf, red cos, green cos, freckled cos, green mignonette and frilly pinks. These are planted into the rich soil of my seedbeds simply by riffling the soil surface, sprinkling on the seed, then sieving compost-fines over the lot and patting it all down to seat the seeds. Then it’s just a matter of keeping them moist, shaded when necessary and protected while small by wire cloches that prevent birds digging them up while looking for insects in the moist soil. After a few months, these seedlings are crushed up and ready to be transplanted into the regular garden beds, and that’s today’s job during the twilight after sunset.
Transplant-shock is exacerbated by heat and moisture loss in young seedlings whose root system gets ripped up after being watered twice per day. So these seedlings are sown into trenches that have been soaked beforehand to such an extent that the sub-soil is saturated and stays cool during the worst of the day’s heat. Once each seedling has been broken out of the clump dug from the seedbed, its roots are laid onto the moist earth at the bottom of the trench. The roots of the whole row of seedlings are then covered with more moist soil. Shade-cloches are placed over the row for over a week to prevent moisture loss over-running the shattered root water supply and to keep out birds. Planting in trenches allows continuous soaking from the low-pressure rainwater tanks without run-off losses or leaf-rot common when over-head sprinklers are used. Then its just a matter of keeping the moisture up to them and the cook away from them until they are ready to eat.
Not much effort, yet substantial rewards at the meal table.


Linda said...

Please "lettuce" know how these go. I follow my father's dictum of reducing by one third when planting leafy veggies. So out with teh kitchen scissors and whack a bit off to cut down on transpiration.

Would not have thought of pre-watering a trench.


Deborah Cantrill said...

I find planting lettuce seeds direct every 2 weeks from Jan- March, monthly every other month gives me year long supply of lettuce. I thin them as I use them -I plant a mix of leaf lettuces like a mix in our salads.It is a little cooler in the hills however I cover my seeds with light shade-ie thin sheets/old thin white curtains(these are lighter than shadecloth & raise the humunity) until they germinate.Result-yummy lettuce every day of the year.