By Hughball
United Kingdom 
We have a hydrangea in a pot which has failed to bloom this year (whereas another one also in a pot has bloomed perfectly - not much difference in terms of sun).
This after 5 years of successful bloomimg. Any idea why this could be - it looks healthy enough.
Ditto for a Senecio in aborder - absolutely no blooms this year, but also looking very healthy in terms of leaves
5 Sep, 2011
Answers
After 5 years it may well be overcrowded in the pot? sounds as if it needs repotting/planting with new compost?
5 Sep, 2011
Thanks for the comments. Yes, we have fed it though not put in new soil. I guess we can try new potting. Anyone know how much watering a hydrangea in a pot requires?
6 Sep, 2011
They are moisture lovers but they do not like to be wet. Fertiliser in best in spring but do not overdo it as this will encourage lush growth and few flowers.They will tolerate full sun but light shade is better in the afternoon. I still think after 5 years it needs a bigger pot with new compost I have just planted mine in the garden mine after 3 years in a large pot. I would certainly think about repotting next spring, which will be the right time to feed it too?
6 Sep, 2011
Many thanks - I think the pot is large enough but I'll try adding compost and more fertiliser.
7 Sep, 2011
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Have you feed and put new soil?
5 Sep, 2011