How To Harden Off Seedlings

This is the time of year to be sowing seeds and if you’re anything like me, your house will soon be overrun with seedlings, no windowsill will be left empty. But what happens when these young plants are ready to go outside? You can’t just fling them out unceremoniously like misbehaving teenagers after a night out on the tiles. These seedlings have been wrapped up nice and warm in the comfort of your home, putting them straight outside would be like tearing the duvet off them as they slept in a warm bed on a winters morning. You need to slowly acclimatise them to the great outdoors before sneakily changing the locks some night when they’re out at a club.

You need to toughen them up, train them, inspire them. You need to start a baby-plant-boot-camp. You can do it seedlings, work it, sweat it, PUSH IT!

Optional, play this to them for some inspiration:

(Also recommended are some leg warmers, one of those jazzy sweatbands for your forehead and spandex everything.)

http://www.youtube.com/watch?v=I5VHYP1jZho

Most people harden their plants off by placing the young seedlings outdoors in a sheltered spot for about 3 or four hours a day, gradually increasing this time over the course of a week. Make sure to bring the plants back indoors each night for the first few nights. After about 7 to 10 days, you can leave them out all day and night until they are ready to be transplanted.

Another way to harden off your seedlings is by using a cold frame. A cold frame is essentially a small glasshouse used to acclimatise young seedlings before transplanting. They typically have a glass lid that can be opened and closed. To harden off your seedlings, place them in your cold frame and leave the lid open for a few hours a day, gradually increasing the amount of time over the course of a week. Close the lid at night time, particularly if temperatures drop. After about 7 days, the plants are ready to be transplanted outdoors.

A couple of tips:

As with all plants, keep an eye out for slugs and snails, they absolutely love young plants and if you’re not careful, will horse into them like a young wan into a Supermac’s on a Friday night after a few scoops.

Keep an eye out for dropping temperatures, it may be heating up but in Ireland, we can still get ground frosts at night up until May. Invest in some garden fleece, you can use this to cover your seedlings from frost damage.

Oh, and just for a bit of fun, what movie had this little gem of a quote in it? (hint: see above video)

“You know what you are?”

“No, what?”

“A tomato.”

“A tomato?”

“Yeah, and I’m running a business here, not a goddamn soup kitchen.”