Keeping the fingers crossed and hoping for the best. Last year lost bloom on good hydrangeas as it was heart breaking to just watch the green growth.

Well, let me think what could go wrong???? Hmmm. Perhaps you remove winter protection in a few weeks but theeeeeeeen, on day 60, temps dive to the 20s, we get 1" of ice, followed by snow, pipes freeze, trees are covered with ice and branches galore fall, we catch allergies and spend the next month sneezing our heads and making the Kleenex Company super-rich! Hee hee hee! LOL!!!!!!!!! What could go wrong? Ha! Oh, me. :0)

Too funny! Hehe

Heck, I didn't put on any winter protection (lol), but have a pile of leaves set aside. I also didn't cut off any old H paniculata flower heads, so those can be used. That's all I'm gonna do this year, if needed ( as well as pile some existing mulch around base growth). No blankets or cardboard sheets for me - they didn't do jack against 25 degrees with a light breeze.

I have 7 macs in pots that overwintered in my shed..I put them in garbage bags then insulated with some leaves and crumpled up newspaper..left the tops of the bags open..just yesterday I unpacked them..all have nice buds..the soil was still damp on 6..1 pot was not as damp so I watered that one..I'm planning on taking them out after mother's day..if I do it before I'll be moving them in and out which is not fun..can leave the double doors of the shed open on nice days..anyone else have potted hydrangeas?

I have summer delight and one nikko blue in pots in garage and they have already leafed out. I was hoping to keep them inside till April.

just took these pics..the one that looks the best was one of the 2 in pots last year..ALL of them have buds..the 4 in the top of the pic were very frail endless summers..just glad they lived..there's a pot you can't see behind the ones in the red bags..the one in the teal pot is a $5 Bloomstruck that was dried out when I bought it..hope the canes leaf out..will be thrilled if I get some blooms..tututara do you have hydrangeas planted outside too? or just in pots? your zone is warm enough without winter protection isn't it?..wish mine was..

I have few outside but only in protected areas. I will take some phots and post them. Many ES, Monrovia Blue Enchantress, Nikko Blue

Im in Maryland (z7) and all my hydrangea are budding, too. How low does the temp have to go, and for how long, for damage to occur? Meaning when is it actually necessary to cover them up?

The roots, if properly watered and mulched, should be able to handle the cold temps but leaves can get zapped if it goes below freezing for long enough. You can remove winter protection about 2 weeks after your last frost date.

Above-ground growth (greening/swelling buds & shoots) can be badly damaged with temps down around 25 F for about 3 hours or more. Blankets and high-piled mulch can help but might be no match for wind.

In 2016 there was a late-April low of 19, which killed everything above ground. The only thing whose buds survived above ground for me (out of about 100) was Lady in Red (mac-serrata hybrid).

The erratic nature of Spring (now "winter" weather) is bothersome, especially with climate change occurring. (Sorry, if you're an avid gardener who doesn't acknowledge climate change - shame on you.) Friday there was a high of 82 here and Saturday night's low was 25. Ridiculous.

I know how you feel. We just hit our first 90-degrees of the year this week! Can you believe that!?!?!? My macs, serratas and paniculatas are behaving normally in winter but my oakleaf hydrangeas have started to keep leaves on thru all of winter; then in the Spring, they leaf out and drop old leaves. That did not use to happen; I would typically see them all loose their leaves by the end of December.

Here is the March 2017 Forecast for the US:

https://weather.com/forecast/national/news/march-2017-temperature-forecast-the-weather-company

Boston Area, when you have, macs 4/5 ft ,winter protection is almost impossible...I have done it all when they were small with great reward...But now Mother Nature will call the shorts ...there so many other options / so many new Hys...Just Saying

Ed..I agree..covering, uncovering, and recovering lots of big yet fragile shrubs is a pain in the #$&..growing in pots seemed doable and is my only chance to have a blooming macrophylla..and someday if I move to a warmer climate they can go with me..