It’s been a while and my tomatoes have grown from seeds to nice little plants with real leaves. Warm weather has arrived and they will soon be planted outside, so it’s time for tomato hardening.

What is tomato hardening?

Tomato hardening or any plant hardening is a procedure in which we prepare plants that grew indoors to their life outdoors. Since outdoor atmosphere is not constant like indoors – there’s wind movement, temperature fluctuations, moisture fluctuations – plants that were grown in indoor conditions or other protected conditions have to be carefully and slowly accustomed to their life outdoors. If you just take the plant that grew indoors and plant it outside, the shift of the conditions may stress it too much and it may die. By slowly adjusting the conditions we allow our plants to more easily adjust to new living conditions.

How to do that?

So, in order to harden our plants we need some sort of greenhouse in our garden. It doesn’t need to be big. Plants just need to fit in it. You can just make it by putting the plants in a wooden box and stretching some nylon on top, or putting the glass top. The only important thing is that the plants ARE NOT completely exposed to the sun, wind, rain and temperature. The exposure needs to happen one step at the time.

The first step is to take you plants out and put them in their hardening box. Make sure they are well watered. Then I leave them for few days so they get used to new surrounding. (This may sound strange, but now they can feel more drastic temperature changes and this is stressful enough for them). After couple of days, if temperatures don’t plummet like this Easter, I start removing the lid during the warmest part of the day. So plants can feel the sun and wind. And close them in the afternoon, when there’s still a bit of heat left in the air.

Every few days, I open the lid earlier and earlier. And close the lid later and later, so that interval of exposure slowly increases. After 2 weeks they should be ready to survive the night temperatures outside, if there are no big cold snaps. I like to leave them in the hardening box a couple of nights with open lid. And then replant them to their outside container. That way they have lower levels of stress and can cope with it.

Epilogue

So, I started my process of hardening the tomatoes a week ago. And they should be ready to plant about 15th of May, which is perfect, since after this date there is no fear for great cold snaps. We had a cold snap this Easter and I’ll be just starting the procedure of lifting the top in the midday. I hope it goes well.

Happy hardening 🙂