My hydrangea has some brown twigs that get new green buds at the top, and some twigs are dead and brown. Am I supposed to cut all twigs to the ground in Fall?

You should remove dead branches down to just above a node in the still living tissue (if there is any). You can do that in spring (there's some risk to pruning in fall because the dampness of the weather etc. may allow fungal diseases to get started). Whether you can cut living branches right back (to above a node) in fall would depend on the hydrangea. Some you can cut back in the fall or spring because they form flower buds on the new growth. I always do those in spring if they need it. Others form their flower buds the year before so if you cut back all branches in spring or fall you will not get flowers for a year. If you want to prune any shrub that flowers on old wood you should do it right after they flower. Do you know what kind or cultivar of hydrangea you have?

I let mine sit over winter. In early spring, those stems that have a dessicated flower at the end get lopped to ground level. All others then get lopped to about 18". This for a blowsy football-flower sized hydrangea (common). No clue about the fancier ones, and this may be totally wrong, but it works OK for me.

Good advice sooby. Keith, If you don't have a photo of it in bloom take a look thru photos of H. macrophylla and H. quercifolia, they bloom on old wood so should be pruned soon after flowering.

It sounds like you may have a Panicle Hydrangea Deb. They bloom on new wood so can be pruned in early spring.
A pic showing the football shaped flowers.

Keith yours looks like round balks of flowers do these should not be pruned now unless you don't care about getting flowers. I believe you have the kind that blooms on mature wood. The panicle-shaped blooms shoukd be cut down over winter and they rise back in spring with lots of new growth and blooms.

Mine is a NOID. I have placed it under H. macrophylla in my list - the old fashioned big blue balls.

Deb, could yours be Endless Summer? Hydrangea macrophylla in general flowers on old wood but Endless Summer is supposed to flower on both (if it doesn't die like it did here ).

Sue, yes, mine could very well be Endless Summer. Or another older variety. Who knows. I've never paid much attention to it - perhaps this year I'll try to figure out when it blooms and on new or old wood. It's more of a background blob of greenery for me - fills in a shady corner well. Some years it blooms much better than others, which may very well be how or when it is pruned. Reliable plant, and I like the blue flowers.

I have a couple of these that came with the house. When I saw this question it intrigued me as I have the same question. I just hadn't gotten around to it. Thanks Keith...

So below are a couple of pictures of one of these.




So any ideas as to prune or not? I do want to see them bloom this year.

@ganinfl
Pretty sure these hydrangeas have blooms that are round balls but a picture from when it was blooming would help. Did you see them in summer? If they are round blossoms then prune only right after bloom; in spring all you should do is remove dead wood.

@SCButtercup

Thanks Judy. The DW and I purchased the home last fall after most of the landscape had stopped blooming. I did take an additional picture of one of the expired blooms. However, it was such a blur that I decided not to post it. From what I can tell, these will produce a round ball type bloom. I think I will skip pruning altogether this year and just watch the progress. I did check the ph and it is being adjusted slowly to produce those blue flowers, if it does...

Good luck, and post photos.
BTW the panicle shaped hydrangeas are spring bloomers. And consider adding one; I have Little Lime, which is small version of limelight. And this kind of hydrangea bloom color unchanged by ph.

again Judy... I am going to need some spring bloomers. There are, lots of azaleas that were left on the property and they are blooming rather nice right now. All are a pink so I need some diversity amongst them.

Thought I would come back and post a photo taken today of the hydrangea...

update
Hydrangea's blooming in my new lawn.