- Sowing in a patch in your garden box
- Thinning your seedlings: what, why, and how
- Pre-sprouting snow peas, winter peas, and sugar snaps
- How to pre-sow with vermiculite
- How do you take care of pre-sown plants?
- Ice saints and hardening off your seedlings
- Pre-sowing zucchinis, cucumbers and pumpkins
- How long do your seeds stay good?
- Are your old seeds still good?
- Harvesting seeds yourself
- Are zucchini and pumpkin seeds unsafe?
- Sowing in a patch in your garden box
- Thinning your seedlings: what, why, and how
- Pre-sprouting snow peas, winter peas, and sugar snaps
- How to pre-sow with vermiculite
- How do you take care of pre-sown plants?
- Ice saints and hardening off your seedlings
- Pre-sowing zucchinis, cucumbers and pumpkins
- How long do your seeds stay good?
- Are your old seeds still good?
- Harvesting seeds yourself
- Are zucchini and pumpkin seeds unsafe?
Ice Saints and hardening off your seedlings
Yeah, it's a weird term. But that's what it's called when you gradually let your pre-sown plants get used to the outdoors. You do this before you move them into your garden box for good.
All seedlings that you pre-sow indoors need this special treatment. But it's especially true for summer vegetables.
It doesn't even need to freeze. If the temperature gets below 5°C, they can die. If it's below 10°C, they won't grow.
So: only move these plants outside when the weather gets warm enough.
What do Ice Saints have to do with it?
Folklore tradition tells us that the very last frost of the spring should occur on these days.
There's little chance of frost after that, and temperatures rarely reach below zero.
Rare, but it still happens sometimes. So keep a close eye on the weather forecast mid-May.
Cold Sophie
"No summer before Boniface, no frost after Sophie."
But you know, that no frost part is never guaranteed. In 2020, it froze on the night of May 15-16. The ground temperature went down to 7°C in some parts of the Netherlands. Not common, but it happens.
Hardening off seedlings
Preparing your plants for the wind is equally important: plants need to be strong enough not to get blown over.
Think of your plants as bodybuilders. A bodybuilder can't lift 100 kg without training. If they try, they'll injure their muscles, back, and knees.
Step-by-step and little by little. That's how training works for people. Same goes for pre-sown plants.
How do you get your plants used to it?
So, on May 15 - or a few days later - put your plants outside for an hour. The next day, 2 hours. The next day, 3 hours. Keep going like that slowly: every day a little longer.
Hardening off with the Planty Gardening app
It waits until May 20, - just to be on the safe side - but it also depends on the weather. If it's been nice for a while and the weather forecast looks good, you can start earlier and harden off faster.
If it's still cold outside, wait a few more days until it warms up.
The right spot
After about five days, most of your plants will be ready to stay outdoors.
As long as the temperature at night doesn't drop below 10 °C. If it does, then you should bring the plants inside in the evening. To a room that isn't heated.
Transplanting to your garden box
Looking for the best tomato, cucumber, and zucchini to grow on your trellis?
We've picked them out for you: you'll find them in the shop.
(Pre-)sowing
- Sowing in a patch in your garden box
- Thinning your seedlings: what, why, and how
- Pre-sprouting snow peas, winter peas, and sugar snaps
- How to pre-sow with vermiculite
- How do you take care of pre-sown plants?
- Ice saints and hardening off your seedlings
- Pre-sowing zucchinis, cucumbers and pumpkins
- How long do your seeds stay good?
- Are your old seeds still good?
- Harvesting seeds yourself
- Are zucchini and pumpkin seeds unsafe?