Where do you live?

I live in NW Washington State (at the tip of the Olympic Peninsula) and my Shasta's volunteer readily. I cut them back in the late Fall and they're up again in the Spring. I'm not sure of the variety, just simple old fashioned Shastas.

I live in Ontario where we get very cold winters and I first planted them last year. I sowed the variety called 'Alaska' which grow very tall (3-4 feeet) with quite large flowers. I did not mulch them, and they are actually growing in an area which is under water in the early spring, but some fall leaves around the crowns may help. The only disadvantage is that this variety tends to need tying up, which is fine for me since I cut the ones which flop and use for bouquets. This year I have planted lots of other cone flowers around them which should keep them upright in future years.
Northerner.

I also have the Alaska daisy on the south face of our house. Loves the heat and I watched it get neglected by my neighbor for years before I asked for a start. I also have another start from WA, but honestly I can't remember the name. It's taking awhile to come up.

My boss has these in 1 gal pots at his business. I prune them back every fall and they sprout out again every spring. We get below 32 F - 0 C at times. They seem to do fine here in Lake County, Calif. I'm thinking of putting some in myself. They are tall about 4' and do tend to fall over some.

I have four Broadway Lights Shasta Daisy that I planted last fall and wintered beautifully. Came up strong and has produced, is still producing, lots of blooms. They're about 3' tall. I actually planted them very late and they came off an almost dead table at Lowes. I have this rescue addiction problem... but I'm working on it. Anyway... they are planted on the S.W. corner of my garage under a tree so they get dappled shade till about 1:00 when they are pretty much in full sun for about 4 hours. We've gotten almost no rain this spring/summer so I water them probably once a week very deeply. Oh, I forgot to mention.. I didn't mulch them last year. Although I do deadhead to get a second flush I do not prune them back till VERY early spring, hoping that if I leave the stems all winter it might help to protect the crown I'm not sure if this helps since you are in zone 3.. but if my poor specimens can make it without mulch or a lot of sun I would think if you mulch and get lots of sun your's might too. Good luck and let us know how it goes

Alexis

Hey there Oly Penn,,, here in North Bend. 30 mins or so East of Seattle on I-90. Brought Shastas with when moving up here in the foothills last Nov.. 07.. didn't get them transplanted til very late winter.. 250 transplants later.. from the old place.. LOL. they have done great even with our unseasonal cold snows and ice last year.. I plan on just lettin em be.. we get 90 inches of rain a year here.. like your rainforest too!.. maybe you don't have them in full sun? I have them facing south.. and in FULL sun ..I love em.. they put a SPARK in the landscape .. and keep them dead headed!!

I am just outside Ottawa, Canada. My Shasta daisy is called Phyllis Smith - the petals are very thin and delicate - it is quite beautiful! Not an agressive spreader yet I have several clumps now from division.

I wish I had your problem. We planted Shasta's from seeds in one flower bed 8 years ago and they became very aggressive. Every fall i dig almost 75% of them out and the next year they are thicker than ever. I live in Saskatchewan so obviously cold weather doesn't bother them

Posie, I'm in zone 3 also and for me Shastas grow like weeds! In fact I expect this fall DH yanked many of them out along with the weedy feverfew when he cleaned up the garden. I'm not concerned, they've already seeded so I'll have enough.

About 10 years ago I planted a package of Shasta seeds, nothing special, probably Alaska, and I've always let them self-seed. It's interesting to see how different some of the plants are.

I don't mulch or do anything with them, they are very tough plants. We get enough snow cover tho which may help them.

I enjoy them even tho they are pretty "common" as the tiny orange butterflies just love them.