Kerria

jbcl

Last year, all the clumps of kerria in my garden seemed to die off. They'd been strong and happy for years. I was hoping they might come back this year, but they've stayed dead.  Any suggestions as to cause and what to do about buying new ones ?

Obelixx

Did they look sick?  Blotched marks on leaves and stems?   There is a newish fungal disease which is affecting kerria.  THe RHS offers this information on it - https://www.rhs.org.uk/Advice/Profile?PID=1018  If it is the fungus, then I suggest you not replace the plant for several years so the fungus spores can die out in your garden.  

If not, then did the plants get water-logged?  They like well drained soil and a sunny position usually.   If that is likely then forking over the affected area and improving drainage with some fine grit and maybe some well rotted garden compost to open up the soil structure will make it more hospitable.  Kerria plants are commonly available at garden centres.

jbcl

Absolutely no sign of disease or distress. Indeed, I was beginning to think I might need to start taking steps to contain them. Next door also had a clump, close by which died at the same time.

Waterlogged may be a possibility. One clump was in deep shade, another round the back of my greenhouse in decent light.

I was wondering if these shrubs have an expected life-span and just die of old age.  A few years ago, I had a beautiful stand of black bamboo which died all at once, and when I looked that up, it seemed that about 15 years is a good age for it.

Obelixx

Bamboo has a life span, usually to do with dying after flowering.

Kerria may be short lived shrubs but they sucker all over and that keeps them going even when the original dies off.  I'd check your drainage and also siting of the plants.  To be honest tho, they flower for about 2 weeks and then are desperately dull for 50 weeks.  I'd choose something with a longer season of interest and less suckering vigour.