Zantedeschia usually falls over with the first frost. Simply clear away the squishy leaves and mulch well. You might also need to give them an additional 'frost hat' . Zone 6, unless you have a favourable microclimate, might be a little too tough for them. For insurance, you could lift a bulb or so and over-winter under cover. They do quite well in pots.

Agapanthus campanulatus? It's said to be evergreen in zone 7 so it may not appreciate being shorn for winter. A good mulch of gravel chips to protect from water-logging will be needed, and perhaps a covering of bubble wrap plus fleece away from the leaves (like a tent) for really cold nights. Air circulation around the surface roots is essential to prevent rot. Keep fairly dry for winter.

Agapanthus is fairly tough, yet it takes several growing seasons for the tender varieties to recover from frost damage.

I live in the USA, but so glad I found this topic.
I grow Agapanthus every year but didn't know how to protect them come winter.

I think perhaps I shall grow them in large pots this year and just lift them in the fall and bring them inside.

I grew them in Southern California, but now live in a much colder climate in Oklahoma.

I found the information here very helpful.
Thank you.

~Annie

Pots. Both of these will survive the winter out of doors in milder parts of England, but Switzerland forget it. I seem to remember skiing there once.....

ianbrazil,

You wrote: "Switzerland...I seem to remember skiing there once..."

You are funny. :)

I hope my Agapanthus come back. I checked them yesterday and their bases seems okay. Not mushy except for last year's leaves. We've had a rather mild winter this year. Some snow, but no extremely low temps.

This year...pots!

~Annie

There are parts of Switzerland where skiing and winter sports happen but not where I live. And I can report that my zanthedeschia not only survived the last winter, when we had temperatures of minus 15ð celsius and no snow to cover the soil, but flowered wonderfully. All of them!
This year we have a lot of snow and the temperatures were not as low as last year. Snow isolates the soil aganst the frost. I shall inform you how my agapanthus are doing later in spring, and I will post some fotos if I manage to upload them.

This post was edited by gartenfee on Thu, Feb 28, 13 at 5:03

Annie - big pots for the Zantedeschia because they multiply so generously. (2gallon/10L with very good drainage seems to give enough room for them to grow to flowering. Wouldn't work for Green Goddess, though. It would need at least 35L to show its best.)

For the Agapanthus: I really strongly recommend that you plant into a big plastic container and then put that into any decorative pot you want to use. Agapanthus seems to cling like an orchid to the inside of any pot and can be very hard to turn out for repotting/dividing. You'll need a sharp knife/hatchet/ spade for divisions, too.

Thanks everyone!

I don't have any Zantedeschia - just the three Agapanthus I bought last year. Not sure what variety they are. I would assume they would be the hardier kind since they were sold for this area, but who knows.

Here is a picture of them in June of last summer. They were finishing up, so not as pretty as they had been.

~Annie

Thank you for the information about Zantedeschia, too, BTW.

I've tried growing them here in Oklahoma, but with little success. The blooms were puny and they eventually died. I planted them in the garden where the soil was damp, but not soggy, and where they got filtered sunlight. They failed miserably.

I would like to have the Giant White Callas like I had in Southern California, but can't find them here.

I will try again using your suggestions for planting them in BIG pots. Thank you so much.

~Annie