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Cornflowers and Californian Poppies

Good evening all!

A few weeks ago, I've sown Californian Poppies and Cornflowers in modules in my plastic greenhouse. They have germinated and they have a pair of true leaves. Why can't I plant them out in the garden before the last frosts? Are they not supposed to be hardy? What is then the difference between hardy and non-hardy plants since you can't plant anything out until after the last frosts. What about the poppies, nigella and calendula that have self-seeded outside?


  • nutcutletnutcutlet PeterboroughPosts: 26,092

    cornflowers are hardy, Californian Poppies less so 

  • I have some Californian poppies in a pot that have survived the winter. Well, last year's growth has died back but new shoots are growing from the same root, next to last year's dried stems. At first I thought they have self seeded, but on closer inspection I realised that wasn't the case. Which of the hardy annuals can I plant outside now?

  • nutcutletnutcutlet PeterboroughPosts: 26,092

    truly hardy plants can be in the garden but need hardening off first. 

  • Thank you, Nutcutlet. Out of the annuals which one would those be?

  • PosyPosy Isle of Wight.Posts: 1,769

    There are many hardy annuals. The seed packet will tell you if your plants are hardy but if you have lost the packet, Google them. However, no plant will be happy moving from a cosy  greenhouse to frosty soil so do harden them off or wait. Another consideration is size. Tiny plants are vulnerable to slugs, scratching cats, foraging birds and even careless weeders. The better the start you give them, the better their chances.

  • Thank you, Posy. You are right in all respects. I have chosen to plant them in a small plastic greenhouse (they haven't been protected much), instead of sowing them directly in the soil, because I thought it would give me more control over where exactly they will end up growing. And also because I don't really like thinning out, especially those seedlings that don't tolerate that. The idea was to germinate the seeds in pots and plant the little plants out as soon as they have a pair of true leaves. After all there are lots of self seeded plants that are growing without a problem and without much damage in the garden already. I have the seed packets, but they all say plant out after the last frosts/ sow directly after the last frosts. I was just wondering what is then the difference between hardy plants and non-hardy when it comes to growing them from seed in spring. 

  • nutcutletnutcutlet PeterboroughPosts: 26,092

    If a hardy annual wakes up on a frosty morning it's OK. A non-hardy annual goes to a sloppy mush

  • Fishy65Fishy65 Posts: 2,233

    Pitter-patter, sowing direct depends on the species I have found. Slugs love to munch on cornflowers in my garden so I sow them in trays until they are a decent size. Corncockle however seems to be ignored and I sow them direct. It's a case of what works for you and your garden, trial and error image

  • Thank you, Fishy. I'm going to plant some in the garden and leave some in the green house. Hopefully I'll be more knowledgeable next year. image

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