Dahlia leaf discolouration

[WobblyLondoner]

My dahlias, grown over a 10 year plus period, have developed strange leaf discoloration.

I grow them in large pots. I thin the stems in each pot to 7-10, and pinch out the growing tips. I added some new compost at the start of the year but didn’t completely repot them.

Initially I wondered if it was some kind of nutrient deficiency (especially as they are in pots) but in googling I see there is a virus called dahlia mosaic virus which has a similar effect on leaves. Has anyone else experience this and if so what did you do? I could try to cut down the affected stems for example?

Basically - help!!

Nobody?!

Dahlias are heavy feeders so it's possible that they've used all the nutrients in your potting medium. I grow mine in pots, lift them every year & store in the greenhouse over winter & re-pot using new compost. You could either re-pot them with new compost or give them a feed every week.

Given the random nature of the patterning, I would say it was a virus

Thanks both. It’s really tricky as I think this either nutrient deficiency or a virus - as the two replies have suggested!

The feeling/hope that it’s not the latter is that the relevant plants don’t have any leaf distortion and aren’t noticeably smaller than their neighbours. The first picture shows the one with the most noticeable discolouration; the second (with multiple pots) also has one pot where leaves on a few stalks have the same markings.

I’ve given them a good feed; I’ll keep an eye on them and if necessary bin the two affected.