Lupins wilting - why?

[Marcher]

I have some lupins I bought from Aldi the other day and grew them in a window box for a while. One hot day thought they were above some black plastic and I noticed they'd suffered from the heat a bit so I planted them in the garden and they seemed fine.
But today one has wilted very badly and looks like it is dying - do you reckon it's because of the heat or is something else wrong?

The ground is a pretty average loam that I added some compost to and it is watered every night during this warm weather (but not saturated).

Any ideas?

[chris]

Either the heat (watering not enough), or overwatered...... or its just transplant shock

(are my guesses)

[Glutton4...]

Check the plant, specifically the top, flower, spikes. There has been a lot of aphid damage this year to Lupins in my area (Essex/Suffolk border). They have been infested with blue/green aphids, and they were being farmed by ants. I have had to cut down all the Lupins in one garden that I tend, as the plants were beyond saving.