Ask the Expert: Red Hot Poker or Weed?

I bought a packet of Red Hot Poker seeds last year and planted them in fresh clean compost in a greenhouse around last July. The packet says Tritoma Mixed Hybrids. They appeared slowly, taking around 6 weeks to germinate and by winter, they were still only about 2 or 3 inches tall. By March this year they were about 5 inches tall. The photos shown were taken last month, they were about 8 to 10 inches tall. (They are now about 12 to 16 inches and still no flower)

They don’t look like Red Hot Pokers to me and some people have said “pull ‘em up, they’re weeds”, suggesting they are Willowherb. I have to admit they do bear a resemblance but I’m not convinced they’re weeds. Surely weeds wouldn’t take over nine months to grow this tall? Surely weeds would have flowered by now?

Any ideas?