You can plant them as soon as your soil is workable (not frozen, not saturated with rain water). Perennials are not sensitive to frost although sometimes tender new foliage can be damaged by sudden cold. Generally it is recommended you gradually acclimate them to being outdoors before planting, especially if they have been displayed/grown in a greenhouse.

I'm no expert but if I wait for that frost date here in northern Illinois it's around May 10th. Lately we've been going from winter right into summer weather. If possible I like to get them in the ground as soon as possible because they grow faster in the cooler weather. This year however the weather is just nuts. Perennials are tough and can take some frost without a problem. Right now it's just to cold. I usually order for the 3rd week in April and since they need to acclimate to sunlight for a few days I just keep them in my wagon and pull them in the garage if night is to cold.they say when to can walk barefoot outside you can plant. Right now your ground in southern Indiana may still be frozen. I'd leave them at the nursery for now and get them at the end of this arctic blast. Their still predicting one more snow storm for next week. Hang in there they'll still be getting plants infor a long time. Arg I can wait either. Good luck-Pat

I am in Ohio and it is too cold to plant outside. Plant things up in pots, and keep in the garage near a sunny window.I just purchased astilbe in bags at Sams. I will plant them in pots and wait till May to put them in the ground just to be safe. We are all so tired of this cold, and looking forward to warmer weather.

they say when to can walk barefoot outside you can plant.

I'm not sure who "they" might be but that is simply not true :-) From a horticultural viewpoint, if a plant is fully hardy for your zone, you can plant it whenever or as soon as the soil is workable, meaning not frozen solid or overly wet. Since the soil never freezes more than an inch or so here under the coldest conditions, perennials can be planted virtually year round. In fact, the defining issue in my climate as to when one can plant tends to be the tapering off of the winter rains -- not the need for warming temperatures.

Frost does not factor into planting conditions for hardy plants. It most certainly does for those that are temperature sensitive, like most annuals. Last frost date in my area is technically considered to be around 4/23 but the only things waiting for that date to get planted are things like impatiens, coleus, tomatoes and basil. I have planted an entire perennial garden in February before without issue.

You will need to acclimate the plants before fully planting out if they haven't already been hardened off but that is the only thing holding you back if you can work the soil.

'they say when to can walk barefoot outside you can plant.'

Oh dear. Then that's about two weeks a year here ;-)

vamppire, I took a look at the weather for your area and not a good idea to be planting now. While a frost might not do much damage, a hard freeze could kill them. Why take the chance. If you have an unheated garage or cold basement to store them in, then go ahead and buy them now. Otherwise, wait until it gets warmer.

its too early .... but i am in off to an appointment.. will tell you why tomorrow..

hopefully you wont be out with a flashlight tonight ..

be prepared to tell me if they were hothouse or greenhouse grown.. and/or hardened off.. when you bought them..

be careful with what that gal from the PNW tells you about late WINTER... she thinks a windbreaker is a winter coat..

it was 26 last night.. just east of you in adrian MI ... greenhouse plants would have died ...

ken

Ken, are you in Michigan? I've always wished I could meet some of the people here on GW. And/or tour their gardens. I'd suggest a plant exchange, but I don't have much to contribute, since I'm in a new place and getting established. I think I'll start a thread on a few of the forums and see if there is any interest in a Michigan get together.

Martha

doc.. i replied to your other post...

the issue is HARDENING OFF ... or where the plants were shipped in from.. or whether they were locally grown in a HOTHOUSE or a cold greenhouse ...

if the fever forced me to buy too early [been there.. done that ....lol] ... i would put the stuff in a wagon.. and pull them in and out of the garage .. until i INSURED the were properly HARDENED OFF.. one might say.. acclimated.. to my local weather ...

here in adrian MI .. just north of toledo.. i would think ABOUT mid april would be a good time to plant properly hardened off dormant perennials ... though would worry a bit.. with frost/freeze potential thru late may ...

a zone appropriate perennial.. should be able to handle such.. but if they are actively growing.. they cant be put out too soon ... as active growth is not as hardy to extreme cold as a dormant plant is ......

plus the transplant itself is a shock.. and frost another shock.. and too many shocks is not good ...

i see you are way south of me.. subtract a week or two from my MI thoughts ....

but with the vagaries of mother nature.. especially during this cold winter.. let me suggest you err towards being a bit late.. rather than a bit early ...

suffice to say.. here is the key .. and it works all season long.. just because you can buy it.. that does not mean its the PROPER PLANTING TIME ... e.g. a fully leafed out tree.. at bigboxstore in july/august.. at a bargain price.. should be held until the proper fall planting time ... not whipped in the ground.. on the day you bought it ...

so.. if you have the need.. start collecting some plants.. protect them a bit longer.. harden them off .. and start planning where they will go ....

never forget.. to really become a green thumb.. you have to kill every plant.. 3 times.. before you succeed .... its how you learn ...

now.. lets focus.. do you have a garden bed to put these into ???? .. that is what we work on.. while the plants are in the garage ... BTW.. the garage is left open all day long.. or the wagon is pulled outside to bright shade ... we arent holding them in a dark cave .. but we dont pull them out into full sun.. in little pots ... too great a potential for drying out the roots ...

and finally.. if you are dealing with a high end.. local nursery.. they ought to know your area.. talk with them. ..

the real caution is dealing with bigboxstores who might be shipping truckloads of plants in from z8 growers.. and that is where a lot of the problems might be .... and that is why the hardening off is such an big deal .... support your local grower.. he will most likely not lead you wrong.. and paying a bit more for a plant.. is worth the guidance ...

ken

Thanks everyone! I did not buy anything yet. We are creating the beds over the next week or two. The plants for sale I am referring to have been outside during our cold weather here. I will wait longer before making any purchases. Better safe than sorry! Appreciate the tips!

I grew up in Bloomington in the 40's-50's. One of the most beautiful areas in the country! As long as your perennials are well hardened off, you can plant them any time now. You are in Z6 so are about three weeks ahead of us here in N IL.

I haven't had a chance to read this thread in depth, but the general recommendation is not to plant new perennials until after your last frost date. The reasons are: (1) soil is harder to work when it is still cold; (2) potential for freeze damage if you plant too soon; (3) cold temperatures stress a newly planted perennial; it is best to minimize stress on new plantings.

I would be interested to know whether most perennials that die back at the first fall frost experience damage when their new shoots emerge in early Spring and are exposed to a late freeze? In other words, do plants die back in fall because the freezes kill them back or does the freeze simply signal the plant that it is time to shut down for the winter? I know some early-emerging perennials, like Bletilla, are susceptible to Spring freeze damage.

This post was edited by mistascott on Thu, Mar 28, 13 at 16:07