In the Pacific NW, new growth doesn't harden off until sometime in July. It's all pretty fragile up until that point. Shipping in April/May would cause a lot of broken and melted foliage — basically an ugly plant for a couple years.

If I had an option, I'd go with a dormant plant and butt it up against a warm foundation until your weather settles out.

Great question. I'm in 5a as well. I prefer to have plants shipped in late March before new growth begins. I like to plant as early as possible also. In my experience, a dormant plant is much more forgiving, especially if root surgery is needed. I also like to get the plants established as much as possible before the heat comes. Last year I started sticking plants March 4th during a warm spell.

Roots are such a huge problem with modern nursery stock. For this reason, I almost never plant out into the landscape in the spring (unless I don't really care if a plant dies).

A preferable technique is to work the roots in the spring, sorting out all of the twisted and tortured flare roots. Replant into a larger pot and give it good care all summer, allowing a robust root system to develop. Then, by September/October, you get a healthier plant and better chance of success.

Thank you both for the greatly appreciated advice! I will go with the earlier March (dormant) shipping option.

ship and plant in dormancy ... avoid severe stress/shock ... in re the period the roots stop working due to planting .... no fresh growth to support ... though planting in the cold//cool spring.. the stresses arent that bad..relatively speaking ....

what was said about new growth hardening up ... those things will flick off with ease ... like putting them in or taking them out of a box ...

dont forget about hardening off .... i wouldnt go sticking them in the ground without such a period ... not to mention.. fresh growth would take even longer to harden off ... they arent going to like some near zero freeze event in MN .... [after sprouting in the pnw] ...... and thats possible into late april or may ...i would leave them outdoors ... but perhaps tuck them in the garage or some such ... if some extreme cold snap came ...

ignore snow ... its an insulator.. its simply not an issue imo ...

in my MI .... i aimed for april planting .... its getting pretty mild by then.. in tree terms ... i would insist to be done planting by 5/1 ... giving the plants 6 to 8 weeks for the roots to settle before the heat of summer might hit ... though if stuff happens .

in my MI ... i have a second proper planting time in sept/oct [perhaps in my MI ... another period of near dormancy.. when the plants are slowing down toward such ]... i dont know if that extends to your area ... i wonder what junkie might think of that ... i think its a midwest thing ...

i am very surprised about what dave says about the PNW .... but he surely should know ... its not like he is some piker... lol ... i am well aware... all advice is regional ... especially in regard to knowing when the heat of summer is going to hit ... [of course there probably is no heat of summer.. lol ...]

i will link below to a planting guide that speaks to me ... the ASC probably has one also .... its closest to how i do things in my MI ....

do you know about bare rooting and root pruning??? .. your post title is brilliant as to being searchable .... if you want info on root pruning ... perhaps another searchable title????

getting plants delivered is like xmas in spring for adults ... im jealous.. lol ...

ken

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

Summer is strange for me. True that it never gets truly hot — rarely over 85°, our issues are no humidity and no natural irrigation from June through September, we're basically bone-dry and if a plant doesn't have good roots, it's not going to make it until fall.

I also don't think it's a good time to plant when a tree is dormant; it's much more subtle. There's going to be a lot of root trauma and if the roots are dormant, there's going to be a lot of rot, especially if you plant too late in the fall as the entire plant is starting to shut down.

For me there's about a 3-week sweet spot in October when there's lots of white root fiber, days in the 50s/60s and nights in the 30s.

As long as the shipping path isn't ultracold the sooner the better as long as you can manage the temperature of the plants in your garage.

Keep in mind that these nurseries have the plants outside in black pots exposed to the sun so they can break dormancy very early. I've gotten plants early March breaking bud so yeah they will harden off in May.

Another thing to keep in mind is to check the overall weather trends where the plants are coming from and what you're going to have. You don't want to have a plant that's been getting used to 60° soil temperatures and then sink them in your 35° soil temperature. This is where you can see some root rot issues.

Most recently I've actually been planting conifers late July. At this point you can evaluate the healthy new growth. Then the roots you sever still grow new roots upon planting. In addition the existing roots you didn't damage put out new roots in fall. I thought this was a terrible idea based on what I've read on this forum but after finding out local nurseries (upper Midwest) harvest conifers that time of year I started planting that time a year with excellent results. Tough part is being able to mail order that time of year. I was able to do it last year due to the cooler summer otherwise I relied on local stock.

Good luck and have fun!

I agree with whaas that late summer is a good time to plant, but it's not a good time to buy, unless you are bargain-hunting and can except the risk. Especially if you mail order you may end up with the runt of the litter.