For healthy plants, timely sowing, fertilizer and correct watering are one thing. But there is a lot more to plant care in order not to undo the progress made so far. Because not only sudden frost can damage your young plants, too much sun during the first time outside can also cause them to suffer. So that your initial effort is not in vain, you should not only wait for the right time to plant them out, but also harden your tomato plants. We will explain below how to do this.
Why hardening is so important
The plants were used to being comfortably warm and relatively shady indoors. If you changed these conditions suddenly, rather than gradually, you would make things extremely difficult for the plants. What will change from now on:
- Temperatures will fluctuate. Indoors the room temperature was relatively constant, but outdoors it changes from warm to cool and vice versa.
- The solar radiation is significantly stronger. In the room or greenhouse the plants haveon the windowsilland very bright. But the amount of direct radiation was significantly lower and somewhat weakened by the glass pane. This is why the tomatoes can get sunburned if the sun is suddenly stronger.
- There was no wind inside, but now there are some stronger winds, which the plants have to be hardened against. However, this part is less a part of the initial hardening, but rather happens gradually on its own.
When can tomatoes come out?
As you know, night temperatures play the biggest role here. Because up to a certain point there is still a certain risk that frost will occur and damage the tender plants. For this reason it applies thatfrom the Ice SaintsEven more sensitive plants are allowed outside. However, you don't want to leave the tomato plants outside around the clock to harden them off, but rather put them away at night, which is why you can start earlier. So, when can you plant tomatoes?
You can get started from the end of April or the beginning of May at the latest. Then it will be warm enough during the day to harden off your tomato plants.
Harden off tomato plants in just a few days - here's how to do it right
Below we would like to give you a short guide with which you can successfully harden off your tomato plants. You have two options for this:
- You take your time and plan up to two weeks for the adjustment phase. In this case, the plants can spend the whole day outside and you don't have to keep track of the number of hours of "freedom" to bring them back indoors in time.
- For a “crash course” you need less time overall, but you also have to be on site to be able to bring the plants back in after a certain time.
So that you don't have to carry all the plant pots out one by one and then back in again, it's worth using a basket, tray or box in which you can transport several plants at the same time.
In all phases of hardening, you should choose locations that are as sheltered from the wind as possible, because the plants are not yet used to wind. That doesn't mean they can't withstand the occasional gust of wind, but it shouldn't be too stormy.
Harden off tomato plants in 2 weeks
Week 1
- Finally the plants can get some fresh air, but be careful about the location. This should definitely be shady and by shady we really mean that there are absolutely no direct rays of sunlightTomato plants reachshould. It sometimes only takes a few minutes for the still sensitive leaves to burn from the sun's rays.
- The tomatoes can then spend the whole day in this shade. Only in the evening or before the sun goes down and it gets much colder can you bring the tomato plants back into their quarters.
- It stays in this daily shade spot for 5 to 7 days.
Week 2
- The tomatoes can now also tolerate a little sun. That's why they can now be placed in partial shade, where they get a moderate amount of sunlight. This is a gentle way to harden the tomato plants without risking burns.
- If the nights are no longer so cold (over 10 degrees), the plants can stay outside, but ideally protected from the wind.
- To be on the safe side or if the weather forecast predicts low temperatures, put them away again.
- After about 5 days of partial shade, you can dare to put the plants in the sun and then plant them in the bed after the ice saints.
Last minute hardening off for your tomatoes in a week
If you missed the time and are now a little late in hardening off the tomato plants, you can also do a “crash course”. However, you should be available in time to stow away the young plants in time.
Day 1 to 4
- Place the plants outside for about 2 hours. Shade is recommended because even minimal amounts of direct sunlight can cause damage. Also protect the tomatoes from rain and drafts.
- Over the next 3 days, keep increasing the time.
Day 4 to 7
- The plants can now also feel the sun.
- Choose either partial shade all day or a few hours of direct sunlight on an east or west side.
- Under no circumstances should the young plants be placed on the south side, where the sun is strongest, especially at midday.
- After the acclimatization week is over, you can follow the night temperatures and leave the plants outside permanently.
- After the ice saints, the plants are hardened enough to be planted in the bed and to survive both the stronger sun and the lower temperatures at night.
Also read:Harden off potted plants in just 3 weeks: This is how it works!
