Acanthus help. What did I do wrong?
On the 2nd of April last year I sowed 5 acanthus seeds in a heated windowsill propagator. All 5 germinated and in July I potted them all into 30C pots. They spent the summer outside and when winter came I decided to leave them outdoors in a sheltered spot and in January when I checked them, although the top growth was ragged, the root systems were white, fat, fleshy and healthy. And so they remained so in mid March, when I thought the worst of the bad weather was behind us, I planted 3 of them in the garden. The root systems were still robust. Then we got hit with the late cold snap. Now all 5 of my plants appear to be dead, even the 2 in pots. The once magnificent root systems are now brown. What have I done wrong?