Hydrangeas not flowering

JenKent

Two years ago I planted 4 macrophylla and one with reddish/purple/green leaves/red flowers (don't know what it's called) all in the same shrubby area, about 3-4 ft apart.  In their first season (last summer) 3 of them had flowers, but 2 of the pink macrophylla failed to have any flowers at all.  I left them alone over the winter and then in early spring (this year) I pruned the dead flowers off and lightly pruned the stems back to a set of buds.  All 5 hydrangeas now have masses of lovely big leaves and flower heads forming on the same 3 that flowered last year.  The two that didn't flower STILL don't have any flower heads forming.  They are situated in a sheltered, part sun/part shade area with other shrubs and a Red Robin (5 years old) and a Rhodendron (ancient), but the other shrubs and plants are not crowding the hydrangeas or overhanging.  I have had to lay a permeable membrane with fine slate over the area to stop neighbours' cats using it as their toilet area.  However, it does get watered when it rains and I do water in dry conditions.  SO, anyone any ideas why 2 hydrangeas are not flowering along with the others? (I can't provide a photo of the area as my phone doesn't have a camera and I can't download from my 'normal' camera).

Lizzie27

That's a strange one Jen. Normally when hydrangeas don't flower, it's usually a pruning error but if three have flowered and two not, it can't be that. Are you absolutely sure that you had four macrophylla ones?  Do the leaves look the same? I'm just wondering whether in fact those two were wrongly labelled and you've got two different varieties
(for which I believe they need a different sort of pruning). I'm by no means an expert so hope somebody else might know.

JenKent

Yes,  leaves on 4 of them are the same - bright green large leaves.  There are three pink and one white.  The one pink that flowered and the white one have huge blooms. The one with reddish/purple leaves has the same shape leaves, but if I remember from last year I think it was a lace cap variety with red flowers.  I've given all of them a couple of feeds with multi purpose liquid feed.  I thought last year that perhaps those two were hydrangeas that flowered in their 2nd year, but so far nothing.  Some of the leaves on the two that didn't flower started to curl and there was 'cuckoo spit' on them.  I pruned those out, but it wasn't drastic pruning - only the leaves and a few tips.  They were mostly unaffected. 

Obelixx

Try some fertiliser for tomatoes or roses or, if you like organic mixes, comfrey based feed.  They will encourage the formation of flower buds.  I believe the new flower buds form just behind the old flowers so try not cutting back any further next spring and see what happens.

If you're worried that means they'll get too big you can control size by taking out one third of stems every year, choosing the oldest and weakest to cut to the base.  This will automatically regenerate your shrubs every 3 years whilst keeping their height and width controlled.

JenKent

Thanks. I'll give them a couple more feeds with some tomato liquid feed. If I don't get any flowers on the two this year, I won't prune anything from them next Spring - I'll just leave them to it and see what happens.  They are behind the ones that are flowering so when I prune the dead flowers off next year, the ones that aren't pruned will act as a backdrop and if/when they flower too, I will have nice bank of large blooms at different height.  At least I'll have a good show of green hydrangea leaves this year (dotted with occasional red, pink and white blooms) in the shrubbery border. It's frustrating though, as I was looking forward to seeing a mass of pink. Fingers crossed that they're just being a bit slower than the others and will eventually start producing flower heads. But, as I said - no sign yet and the others are streets ahead.  All my other hydrangeas (4 in total) in other parts of the garden are forming lots flower heads, and I pruned all of them exactly the same and at the same time at the end of March.  I'll give them a good talking to!

Obelixx

That may well work.  I once gave an underperforming group of bearded irises a final warning and they flowered their socks off the following year.

cclaf09

Hi JenKent, I have a problem like yours, my hydrangeas did not bloom last season. The first thing I did was to blame a bad pruning, I went to a lot of information on the web (including this article on pruning hydrangeas), perform a supposed correct pruning but nothing, they still do not flourish. If at any time you manage to make your hydrangeas bloom, please count here as you have done, I will apply it in my garden.

JenKent

This will by my hydrangeas 3rd year.  I plan to prune half way down and not right to the ground as before.  I also plan to give them a good liquid feed at the start of the season + a good talking to!  Mind you, after I posted my query last year, most of my hydrangeas in other parts of the garden only had one or two blooms whereas most years they are full of bloom.  Perhaps it was a 'bad year' for hydrangeas.  The only one that did really well was the white one in a large pot.  It had masses of huge blooms, which were so heavy I had to tie them up.  Perhaps it was all due to the dry, hot conditions - although I did water them all every day.  I kept an eye on neighbours' plants as well and they seemed to lack the amount of usual blooms as well.  Looking forward to the Spring and to getting out in the garden again. Thanks for your comments.