Young delphiniums dying

gardeningfan

I'm trying to grow delphiniums from seed. I've been sowing batches since spring without success.

After they germinate, I pot them up into 9cm pots with Wyevale's Multipurpose compost with added John Innes (the orange bag). I move them outside the greenhouse and water them every 2 days in this hot weather. But after a month or so of good growth they mostly die off. The leaves go brown and when I pull it out there is very little root growth.

What am I doing wrong? Is it the compost?

Lyn

I don’t prick out delphiniums until the are big plants, they don’t transfer well as tiny two leaf seedling. At least, that is what I find, other may disagree but I grow loads of them, and leave until they are bigger. 

ERICS MUM

Lyn said:

I don’t prick out delphiniums until the are big plants, they don’t transfer well as tiny two leaf seedling. At least, that is what I find, other may disagree but I grow loads of them, and leave until they are bigger. 

I do the same with foxglove seedlings. They germinate in the gaps between the patio paviors and I leave them until about 1.5 inches with 2 or 3 pairs of leaves before potting up. 

No idea if this applies to Delphiniums too but I have a hunch it does.

gardeningfan

I'll try leaving them longer then. Maybe try a different compost at the same time.

Posy

If the roots are very undeveloped it may be your compost. However, the hot weather may not be helping, either. Try a bit of shading while they get established.

Fairygirl

Whatever the plant is - it shouldn't be sitting in sun when it's small. Even 'sun lovers' can't cope with that when they're in pots of that size. 
When you  have them outside [and they really shouldn't be inside at this time of year ] they need to be in  a shadier site. Transplant when they're  a reasonable size, as Lyn says,  and that should help