Hello, I'm new to the forum and new to gardening so please bear with me. I bought a house last year and it came with the seller's prized hydrangeas. The ones on the side of the house were amazing big balls of white and were so prolific and lovely. The ones at the back of the house were beautiful as well but were blue and purple and accented our backyard so wonderfully. They now appear to be different varieties of hydrangea. The white ones at the side of the house are full of green sprouts all over the branches and they look quite healthy. The multi color ones at the back of the house, however, have green shoots coming up at the base, but their stems have no green leaves or buds at all. It almost looks as though the stems and old buds are dead.

1)Are these different varieties and hence grow differently?
2)Should I prune back either variety now for best results this growing year? (Central Michigan, East Lansing area)

I included 2 photos of the ones in the back that appear to be struggling. One a detail of the new sprouts emerging from the base. And I included one photo of the healthy side yard hydrangeas.
Thanks in advance for taking the time to help me keep our yard beautiful!

Welcome to NGA, Scofield23. Without pictures of the blooms, it would be difficult to tell for sure. But yes, I suspect that there are two varieties of hydrangeas growing. See the link below for pictures of the blooms that the different types of hyddrangeas produce:

https://plantaddicts.com/types...

Multi-colored blooms suggest that you have a hydrangea macrophylla, usually just called a mophead or a lacecap due to the shape of its blooms. They are the only hydrangeas whose bloom responds to the presence of aluminum in acidic soils (by turning the colored blooms a shade of blue), the presence of aluminum in alkaline soils (by turning a shade of pink) or the lack of aluminum (by turning a shade of pink). Some varieties mix the colors and also show shades of purple.

Mopheads are more sensitive to cold winters and to afternoon/evening sunlight (makes the leaves wilt in the summer). Their stems tend to get zapped by winter cold if one does not winter protect them. If they are winter protected, the stems will leaf out and they will bloom in early/mid(?) Spring from invisible flower buds that were developed at the end of the summer or around the start of autumn. If those stems do not leaf out by around the end of May, there is a very low chance of leaf out and so, they can be pruned all the way down.

While the stems may be zapped, the roots are not, so the roots will send new growth in Spring. If the mophead is a type commercially called a rebloomer it will bloom again. Examples of this are the Endless Summer Series, the Together & Ever Series, the Let's Dance Series, etc. Rebloomers are not really rebloomers. They are remontant and might produce blooms from this new growth that you see. If the stems get tall enough and old enough before winter sets in the the Fall, you will see new blooms from the new growth. Usually their invisible flower buds open in the Summer months (they look like small broccoli heads).

There is also another type of hydrangea called a Smooth Hydrangea or an Annabelle Hydrangea (because of its most popular hydrangea). That may be the other one that you have. It is winter hardy to Zone 3 so it tends to handle winter better. It produces white round-ish blooms in late Spring -ish, although some new varieties can produce shades of pink that hardly change when there is aluminum, when there is not and when there is but the plant cannot absorb it (in alkaline soils). As before, wait for the stems to leaf out. If they do not leaf out by the end of May, you can cut these down to the ground. Smooth hydrangeas produce blooms from invisible flower buds that they develop in Spring, probably in mid-to-late Spring where you live.

It is probably best not to prune some of these smooth hydrangeas. I cannot tell which variety you have but, s-o-m-e varieties tend to have large blooms that cause the stems to flop when the blooms get wet and weight too much. It is therefore best to let the stems' wood get older and harder by not pruning so they will not flop as much.

When it comes to pruning, hydrangeas do not have to be pruned if they are planted where they can attain their estimated size at maturity (given in the plant label). So pruning is not something you should make a habit of. But we gardeners like to prune in Spring. So, there are some cases when it is ok: you can prune branches that cross; you can prune branches that grow "too much" and are aesthetically "out of sync" length-wise from the other stems; you can prune branches to let more sun into the inside of the plant (useful when you have fungal issues); you can prune plants that are growing into walkways; etc.

Deadheading is not the same as pruning but it refers to removing the old spent blooms from last year. The blooms are held by a single string and they attach to the ends of the stems. This is an area where flower buds for this year will develop. So deadhead by cutting the little string that connects the bloom to the stem and not by pruning the end of a stem. I typically let Mother Nature do the deadheading for me but you can deadhead in the middle of winter or at the end of the summer.

The link below talks about pruning hydrangeas. At the bottom of the page, they also talk about deadheading.

https://plantaddicts.com/pruni...

Lastly, there is another type of hydrangea that you may have, instead of those Smooth Hydrangeas. They are called paniculatas because they produce panicle-shaped blooms. They too are winter hardy to Zone 3 and most produce flower buds & blooms in late Spring to late Summer. The leaves on your last picture may be of a paniculata but since it looks like it just leafed out and the leaves are so tiny, I am not 100% sure. Some varieties get quite large and newer versions tend to be more compact. The majority of paniculatas' blooms start either green or white, then turn white, then get some green and-or pink splotches, then they turn brown. Paniculatas are the most sun tolerant of all hydrangeas and in northern climates, they typically can be planted in full sun.

Does that help you, Scofield23? Luis

Luis,
Wow! That is a wealth of information. Thank you so much. It sounds like it won't hurt if I just leave them and see if they blossom late summer not knowing which variety they are. I was worried that if I didn't cut them down, that I might miss a window for proper pruning that would give energy to the growth of summer blossoms. I really appreciate your help!
Scofield23

Hello,

I also have a problem with the Hydrangeas I bought a few weeks ago. It seems like the leaves are starting to dry out and wilting....I'm not sure what could be the problem

Where are you located (city, state)? When did the leaves start to dry out like this? Looks like powdery mildew though.

Luis,
I wanted to thank you again and give you an update on my hydrangeas. A week or so ago I finally cut down the wood from the hydrangeas in the back as it was certainly dead. The wood was hollow, brown and brittle. In the period of time since then, I've turned on the irrigation system and the weather has become significantly warmer. The little buds that you can see emerging from the base of the old wood in my first post are full leaves attached to new wood that are shooting up rapidly!(pic 1) I have 5 or 6 of this variety all in the back that are coming up nicely now (pic 2) The ones in the side garden that were budding on the old wood have taken off like crazy as well (pic 3) and the one plant in particular is spreading like crazy towards the walking path. (pic 4) I'm looking forward to the beautiful blossoms in the summer and wanted to update you on their progress as I doubt that you ever hear back from panicked gardeners half of the time. So thanks again Luis!

Looks good. The dead wood is typically hollow as the inside decomposes so much faster.

New pics 1-2 do resemble what I would expect mophead hydrangeas to look like now. New pics 3-4 have leaves that resemble smooth hydrangeas like Annabelle and its cousins.

As temperatures hit 85F and higher, you will have to ratchet up the amount of water from "Spring levels" to "Summer levels" due to heat stress (sunlight, lack of water, lack of environmental humidity, windy conditions). Mopheads (hydrangea macrophylla) are more sensitive to heat stress because they have large leaves that loose moisture faster than the roots can absorb more water. But smooth hydrangea (hydrangea arborescens) is not too far back from the list of heat sensitive hydrangeas so keep an eye on it too. Specially those nearby rocks that reflect sunlight towards the plants and that can sometimes leech minerals and make the soil alkaline.

Too much alkalinity can make the blue blooms turn purple or pink. And if the alkalinity bothers the plant enough, the leaves will turn light green to yellow but the leaf veins will remain dark green. At this point, you really need to do something about it and that is to amend the soil with either garden sulfur, greensand, aluminum sulfate (do not apply a/s near azaleas or rhododendrons though) or iron-chelated liquid compounds.

By now, you should have replaced any mulch that either "disintegrated" or got blown elsewhere. They should have 2-4" of the stuff up to or beyond the drip line. This will protect the roots from temperature extremes and lengthen the time between waterings. Use the finger method daily for 2-3 weeks once temps are above 85F to make sure you are watering ok. Early in the mornings (6-8am), insert a finger into the soil to a depth of 4" (that is the typical depth of hydrangea roots) and water if the soil feels dry or almost dry). Every time that you water, also make a note in a wall calendar or an electronic calendar saying that you watered x gallons on that day. After 2-3 weeks of doing this, review the notes on the calendar and average out how often you were having to water. You should be able to come up with an estimate like 'watered x gallons every 3/4/etc days'. Then set the sprinkler to water x gallons every 3/4/etc days. If temperatures change by 10-15 degrees and stay higher/lower then consider using the finger method again for another 2-3 weeks to see if you need to tweak things.

The following estimates are for a newly planted hydrangea here in early Spring and can vary due to climate, soils, etc. You can start watering 1 gallon or so each time you water each plant. As temperatures go up above 85F then increase the amount of water per plant per watering to 1.5 gallons. If temps go above 95F then use 2 gallons. Above 100F, water if needed but water the soil manually. Once temperatures go down in the Fall, reverse this process. As temperatures go below 100F, stop hand watering. As temperatures go below 95F, water 1.5 gallons per plant per watering. A temps go below 85F, water 1 gallon per plant. Tweak as needed for your conditions which may require even much, much more water than those numbers. Once the plant goes dormant and the leaves brown out, water once a week or once every two weeks depending on local rains. You can stop watering if the soil freezes, if the temps are too close to freezing most days or if the soil feels moist due to rains. Resume watering when you observe leaf out and start at Spring watering levels 1 gallon per plant.

To determine if you watered enough gallons of water, water the soil from the root ball outwards in all directions. Sometime after watering, insert a finger into the soil to a depth of 8" and see if the soil feels moist. If yes, the number of gallons of water used was enough.

Annabelle can propagate via suckers sometimes so, if this is not ok with you and you see suckers, plant the suckers in pots and give them to your neighbors, friends, relatives, etc.