Are mophead hydrangeas hardy to zone 5

south central, WI(Zone 5a)

I got a plant as end of season "pretty". As it looks healthy, is pretty with red/green florets..thought I would check to see if you folk could give me some info. I am in zone 5..with clay or ammended clay as soil Will have Lots of shredded maple leaves for mulch.
Any help appreciated.

Dublin, CA(Zone 9a)

Is it a reblooming cultivar? (if it came without a name, I'd assume it's not a rebloomer and will only bloom on old wood). If it's not a rebloomer, you'll definitely need to protect it if you want to see flowers next year.

south central, WI(Zone 5a)

No tag and no information available. Will take photo when I can..(leaf burning is keeping me in the house)..didn't know that they could burn leaves in town :(

Dublin, CA(Zone 9a)

Most of the reblooming ones are patented and required to be sold with a tag that has the name and the patent information--of course tags can still fall out but for now I'd probably assume it's one that just blooms on old wood. (Hydrangea cultivars can also be tricky to ID because the color of the flowers varies with age, soil pH, etc)

Hurst, TX(Zone 7b)

You could try going to this website and try to get a general idea based on the blooms shape:

H. macrophylla - has the well known mophead blooms as well as lesser known lacecaps; produces invisible flower buds in July-August.
H. arborescens - has mophead blooms but they are much larger than H. macrophylla mopheads; very winter hardy; stems tend to plop down or bend sometimes due to the weight of the blooms and somewhat weak stems; recent "clones" advertise they can hold the blooms better; usually have white blooms at first but new clones can also start pink (and remain pink); some arborescens can have lacecap blooms too; produces flower buds in late Spring to early Summer
H. paniculata - panicle shaped blooms that usually start all white or maybe greenish; very winter hardy; can be grown as trees; can handle more sun than the other varieties; can be grown in standard form (tree like); probably the largest variety too but new/recent introductions include smaller versions like Limelight and Little Lime, etc; produces flower buds in late Spring to early Summer
H. quercifolia - the leaves look like oak leaves; have panicle shaped blooms too; winter and drought hardy once established but does not like sitting in wet soil (gets root rot); nice fall foliage; produces invisible flower buds in July-August
H. serrata - has serrated leaves and lacecap blooms; tends to leaf out and bloom later than H. macrophylla; produces invisible flower buds in July-August

There are others but these are the main ones found in local nurseries. Care is basically the same... if the missing tag were to say how hardy this one was. Protect from summer afternoon sun; maintain 3-4" of mulch up to the drip line; fertilize in June where you live; if you need to, it is safest to prune after it has bloomed but before the start of July; maintain the soil moist, not wet, at all times (stop watering when the ground freezes and only water every week or every 2 weeks when dormant & the ground has not frozen). Winter protect if it is a non-reblooming H. macrophylla; H. macrophylla mophead/lacecap flower buds develop (but are invisible) in July-August & will usually die during winter if planted in very cold zones like yours and if not winter protected. Most of the others will develop flower buds and open the flowers in May-July. Ammend the soil if your soil is alkaline using products such as green sand, iron phosphate, aluminum phosphate, garden Sulphur or iron-chelated liquid compounds sold at most all nurseries.

This message was edited Oct 22, 2012 6:26 PM

Elgin, IL(Zone 5a)

What a great summary. I have several hydrangeas and have read lots of books but this is the best summary that I have ever seen.

Thanks! I've bookmarked this and am going to use it this fall.


south central, WI(Zone 5a)

Thanks so much. I have it planted in the shade, with amended soil (added compost, instead of Solid clay) There is Lots of iron in this soil. We have to have an Iron Curtain on the H2O..and still get iron stains.
Will be getting test kit, when I have a few extra $$
I am hurrying to get, at least; the bare root plants which I have been holding over..into the ground. I am trying to accept that the potted daylilies and vines, will once again; have to wait to get planted. Will be chopping leaves for mulch..mostly maple as we have moved from my oak trees.
Will keep track and let you know,.

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