Are these dahlias stunted?

BenCotto

I’ve never grown dahlias before so don’t know what to expect. 

The variety is Katie’s Velvet, a dwarf collarette ultimately reaching no more than 80 - 100cm. I planted them as garden-ready plants in early June, nipping out the growth tips two weeks later. The bed faces South but it was enriched with abundant stable manure last autumn and it us generously watered every two or three days. Unfortunately the plants have not put on much growth over the past 6 weeks and the growth tips seem a little wizened; ants are climbing over some of the plants.

What’s the verdict? Should I be doing things differently? Do I just need patience?

Thank you for any help.

fidgetbones

The ants are farming blackfly. You may need to spray them with an insecticide or a squirt of washing up liquid in a sprayer. Even hosing them off will help. I always find collarette dahlias only grow to 12 to  18 inches.  They are usually described as dwarf, so I wouldn't expect them to get very big.

BenCotto

A very belated thank you, fidgetbones. It was indeed blackfly which set the dahlias back a while but they are growing apace now though yet to reach their floriferous best.