Nine-Star Broccoli -- Annual or Perennial?

Have anyone in a Zone 5 or 4 ever tried growing Nine-Star Broccoli as a perennial? There seems to be conflicting information base on the research I have done online.

Thanks,
Kris

It is definitively a perennial.

I live in zone 5-6. Iceland. Problem is that hard freezes come often without any snow. And in early and late summer, freezes still occur, just after mild weather.

I started my first perennial broccoli in 2011 from seed. I could harvest broccoli that summer. Then, a few plants survived into 2012, and again I harvested a few broccoli heads. In 2013, the plants are still alive outside, even after two summer harvests. One plant even did flowered and produced a bit of seed, and kept alive afterwards, but it is recommended to never let the plant go to seed.

I have no idea how long can this continue, but it might depend in both: 1) severity of your winter, and 2) how short is your summer. I think a mild winter and a short summer are favourable to induce and select for the perennialization of broccoli.

The difference to normal broccoli, is that normal broccoli always dies after a summer harvest. But perennial broccoli sends new growth from its root and side shots, but new heads will be smaller than in first year. So far it has extended growth into its 3rd year, so it is really a perennial, but probably short term. I do not know how long it will remain alive.

Here in Iceland some normal broccoli plants did not flowered last summer, and they are still alive. I think they will produce broccoli next spring, as weather warms, and who knows if one or two might perennialize as the 9 star variety. I also let many of them cross and set seed, in hopes of getting more perennial types.

I've had nine star 'perennial' broccoli, but it didn't survive after flowering for me (cool maritime climate). I did manage to collect some seed, so I'm going to have another go at growing it. Maybe if I harvested all the flower heads (rather than the seeds!) it would have survived another year.

Yeah harvesting all the heads before they flower is probably the key. Mine did the same the first year, bolted and that was it. Second time round I was more aggressive about cutting them early and it came back. Still not as reliably perennial as advertised but worth persisting with.

Nancy Reading wrote: Maybe if I harvested all the flower heads (rather than the seeds!) it would have survived another year.

I've had Russian Kale go multiple years so long as I'm reliable at chopping the flower heads back early. What I've found with it, is that as it gets older, it is less productive. Slower growing and smaller leaves from my observations.

By comparison, I've seem pictures of some variety of perennial Kale that's like a small shrub and seems to genuinely keep producing longer.

I imagine the catch with 9-star broccoli is that you *want* it to flower, but you want to interrupt that process by reliably harvesting so that the flowers don't get to the 'make seed' stage. I would want to plant that somewhere where I would see it every day, and commit myself to harvesting it every day during its busy season!

Most 'tree kales' are perennial because they almost never go to seed. Generally if they do, they die. So not a 'true' perennial.

In Portugal we have a 'perennial' bush cabbage that is mostly perennial because the flowers are religiously removed every year, usually at the bud stage so they can be eaten as broccoli. Eventually the plants get a bit too big and unwieldy so they are allowed to seed, which they do very freely, and then generally they die. Most live for around six or seven years if the flowers are removed.

Just occasionally one survives seeding though. And I've been selecting for ones that survive seeding. So far the longest lived one I've had that has never had flowers removed lived for four years, seeding three times.

Here's a photo of one of my best ones.  



I wrote a bit about it here.

I'd always heard that nine-star perennial broccoli only survived if you religiously harvested the brocolli. I bet it could be selected to survive a bit longer though...