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Overwintering non hardy plants


By Samjp

Staffordshire, West Midlands, United Kingdom Gb

Quick question for overwintering non hardy plants.

Firstly I have a Cordyline in a pot on the deck. We have lost two to harsh winters in the last few years so I would really like to keep this one. I don't have a greenhouse but had thought about moving the pot into the shed (if I can find space) or the garage. Neither is heated and the garage has very little light and is prone to flooding. If I move it in the garage we do have some old house bricks so I can build a bit of a plinth to make sure it doesn't sit in water. Alternatively I could see about moving it into the house. What do you suggest is the best option?

I also have a couple of pots of herbs (rosemary, thyme, sage, mint, oregano and parsley) will these be ok outside or should I move them indoors. I could probably get them into the conservatory (tends to be fairly cold in there as we don't use it very often).

I also have some annuals that I thought I might have a go of overwintering (if its possible). I have a white cosmos and a few new guinea impatiens. They are currently in the border but I had wondered if they would survive winter if I brought them indoors in pots (either the conservatory or the warm house)?

Finally I have a couple of pots of plants that haven't been put in (a ferny thing and a grassy thing I got out of an old plant - self seeded, a skimmia and a hebe) the borders yet. If I dont get the in the borders for the winter - which is looking likley at the moment - whats the best thing to do with them?

Ohh one last question if I move pots into the garage/shed how often would I need to water them?

Thanks guys.



Goodness - so many questions all at once!

I would leave the Cordyline outside, but wrap it in sacking and stuff straw inside the sacking to protect it. I'd also wrap bubblewrap round the pot as insulation to stop the roots from freezing, and move it to a sheltered spot.

Herbs - mint and origano die back in the winter, but all the others are hardy, so they could stay out. Group the pots together, and bubble wrap the pots.

Annuals - you might get a few more flowers on your Cosmos inside, but remember that it IS an annual, and it'll die. The New Guinea Impatiens make good houseplants and with a bit of care would flower for ages. You could take cuttings from them, too.

If you can't plant the other things, then bubblewrap the pots and leave them out.

Phew! Good luck. :-)

27 Aug, 2011


Okay tackling your questions in order so far as possible:

Others who grow Cordylines may give you more advice but I would not put into either the shed or the garage - too dark and wont help to keep the tree warm. Why not put in the conservatory with the pot well wrapped in bubble wrap and then you can swaddle the Cordyline in fleece in the cold weather.

Herbs: Rosemary, sage, thyme,oregano and mint will all be fine outside particularly if up against a house wall. Rosemary may need some protection if the weather gets really bad. You could move them all into the conservatory if you are concerned.

Annuals are just that they flower once and then they die.

You would do well to get your plants into the ground now and let them establish before the winter. Plants in the ground survive much better than those in pots. If not again you need to put them in your conservatory and protect from severe cold.

27 Aug, 2011


Use the conservatory and buy an electric greenhouse heater with a frost-stat. It will only operate when the temperature is very low and will keep the conservatory at above zero degrees.

27 Aug, 2011


There is a perennial Cosmos but the in the UK you normally only find the annual varieties. The self seed pretty well.

27 Aug, 2011


Thanks guys most helpful as always :D.

I'll move the cordyline in the conservatory then. I don't think it ever gets below freezing as it is linked to the living room and kitchen which should keep it warmer, but I'll keep an eye on it. Might have to move it fully into the house over Christmas, don't think there'll be enough room in there with the Christmas tree.

Should have plenty of room for the other little pots in the conservatory. The hebe and the skimmia haven't been planted because the whole border needs clearing of the rubbish and digging. I don't want to do that before the new fence is put in. God only knows when we'll get a new fence though lol, the old ones been falling appart for a couple of years now lol. They keep saying it'll be sorted, even got a couple of quotes but nothing yet :S.

I'll have a look at trying some cuttings or see if I can collect seeds from my annuals then. Wasn't too certain they would survive but thought it was worth a go they are so pretty. Will definately have to put some new ones in next year if they don't take.

Thanks again :D

27 Aug, 2011


You can collect seed from annuals but cuttings wont work.

28 Aug, 2011


They do from the New Guinea Impatiens, MG. My friend pops them in water and they root!

28 Aug, 2011



28 Aug, 2011


Ohhh I'll give it a go then.

Spritz do you know if your friend does anything in particular to help them root? I'd presume (never taken cuttings before - or collected seeds thinking about it lol) I would need to take a strong stem which has a few good leaves, but to look for a stem without any buds. Then since your friend gets them to root in water, just pop them in some water and hope they root. Once rooted pot them up. Am on I the right track here.

Thank you for your response, they are very helpful to a novice gardener :D

28 Aug, 2011


Yes, spot on. I know they can also be rooted in damp vermiculite - so you could try both ways! Good luck. :-)

I've got Penstemons, Gaura and Persicaria cuttings in jars of water at the moment - they're all beginning to root.

28 Aug, 2011


Ordinary busy lizzies (if you have any left!) will root in water as well. Before they were popular bedding plants I remember they were often used as house plants and people gave each other cuttings rooted in water.

28 Aug, 2011


I always root my busy lizzies in water.... i just get a glass stretch clingfilm over make a few holes in it and pop stems in ...after a few weeks ( remembering to top up water) hey presto new plants. It works particularly well with the straggly stems that spoil the plant as it gets enjoy!

31 Aug, 2011


Thanks everyone I'll give it a go in a week or two. My impatiens have masses of flowers on them at the moment, don't want to start chopping bits off yet :D.

Lisa thats a great idea with the cling film, thanks for the tip.

3 Sep, 2011

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