When to put marigold seedlings outside?

[Gardening2024]

I have some marigold seedlings that are getting quite big now. I know it’s too early to put directly outside, but I’ve got one of those little plastic greenhouse things (the ones with shelves and a polythene sheet cover thing that goes over it), would it be ok to put the seedlings in there now or is too early / cold?

I’m also planning to plant some runner bean seeds tomorrow. When they germinate should I put them straight in the greenhouse?

Thanks!

Do you know which kind of marigold? Calendula (pot marigold) or Tagetes (French or African marigold)?

The packet says they are French dwarf double.

It’s way to early for runner beans, I normally put them in trays in the greenhouse towards the end of April to go outside at the very end of May

You need to do what is called 'hardening off' for any tender bedding and frost-susceptible seedlings. This involves acclimatising them to outdoor conditions by, for example, putting the trays of seedling outside where there's a bit of warmth and protection from wind which is currently very chilling and bring them indoors at night which could include a garage if it's integral as some of the warmth will carry through from the house.

repeat for around 10 days through April and keep watching the forecast for your area. Any frost which is highly likely until mid-May and you could risk losing them. Once hardened off, they will be fine in your mini-greenhouse if it's up against a protected South facing wall.

Thanks, this is really helpful to know. I’ve been hardening them off for the last few days, I’ll continue with that for another week or so and then see how they get on being left overnight in the greenhouse.

Thanks for the advice. Do you plant the seeds in trays inside first and then move them to the greenhouse end of April? Or do you plant them directly in trays in the greenhouse?

I plant them in trays in the greenhouse the last week of April and leave them there and then harden them off outside towards mid to late May.