Mixed perennials

[Snadger]

I have two seed trays with about 24 modules in each full of mixed perennials grown from seed.
They are in the greenhouse and have put a spurt of growth on. As they are hardy perennials would I be better leaving them outdoors as there growth is lush and soft.

I'm frightened that the trays freeze during the winter. I should maybe clear a cold frame and bung them in there?

What do you think?

First time I've ever used three 'confused' emoticons!

[Scarlet]

I normally leave Autumn sown perrrenials in the GH. If they are small modules perhaps you could pot them on?

[Snadger]

I normally leave Autumn sown perrrenials in the GH. If they are small modules perhaps you could pot them on?

Thanks for the reply Scarlet. They were originally sown in small modules and have been potted on to bigger modules. They are romping away so I've either got to slow them down or pot them on. Do most herbaceous perennials die back in winter or do they keep their foliage and just get bigger and bigger?

[Scarlet]

Well they usually stay small and green. This very warm Autumn has probably encouraged more top growth than you need. If you pot them on, it should slow them down and encourage more root growth. I'm in the same boat, I've got some lupins that are much bigger then your average autumn sown plant. I'm potting them on and keeping them outside to slow them down, when we are forecast a drop in temperature I'll keep them in the GH to give them a head start in spring.

[Kristen]

Mine are in 1L pots now, outside, and I will move them back into the greenhouse and keep them relatively dry over winter before planting out early in the Spring (before they make a lot of soft growth in the greenhouse)

Need to watch out for the rootballs freezing - pots have a much larger surface area that will cool down, compared to a plant in the ground with just the surface area of the ground radiating heat - but that will only be an issue if we get prolonged cold with -5C temperatures or worse.

[Kristen]

P.S. Don't over-pot them, going into the winter, otherwise the plants won't be able to "drink" the water that you give them as the pot will hold far more than they need. Mine have been potted on from seedlings to small modules, then 9cm pots and finally 1L pots.

[Vince G]

We're currently digging up and replanting a couple of large beds in the back garden. So we ordered one of those bumper perennial packs from J Parkers. Nice healthy plants, which are getting quite big in the polytunnel. Intend to keep them there over the winter, if they die back, so be it, but they have had a better start in life in the poly than they would've done outdoors, so once hardened off next spring I would expect them to rocket away with all that extra energy they had stored.