I planted Red Russian last year and have put the rest of the pack in this year because it was so sweet. Bought the seeds from Seed Savers Exchange but I think Johnny's has it, too.

I grow a lot of Kale because i juice it each day. Lacinato or Dinosaur is my favorite for juicing because it does not get as bitter as Red Russian or Blue curled scotch kale. However, red russian grows extremely fast and will yield more in my experience. I also higly reccomend Redbor Kale. It's quite good and bery ornamental looking in the garden.

I'm trying Rainbow Lacinato this year. Frank Morton crossed Lacinato with redbor.

Kale is bitter in the heat. When it gets cold and frosty, it sweetens it.

I have to admit a preference for the Dinosaur as well, but there may be a variety better suited to your much warmer climate than I have.

Yes, heat during growth makes kale bitter, but I did find last year that spring-grown red russian was still fairly mild flavored in May, when we generally start heading into weather consistently in the 80s, sometimes hitting 90. That's to give you an idea, you wouod have to translate it into your own climate timeframe. Overwinted blue curled scotch can be quite nice in the very early spring, too. Otherwise it's like collards, a fall and winter crop.

To the kale veterans out there...

About half my overwintered kale (all Red Russian) are starting to bolt due to the recent 80-degree highs.

Do I cut 'em all to the ground now? Cut the flower stalk and continue trying to harvest?

Not a vetran, but one of my collards did the same and I opted to cut it and eat it, because I thought that once flowering was initiated it keeps going and the leaves produced get smaller. I'm keeping the ones that haven't started flowering out there until they do.

Thanks everyone for the great replies -- that's really helpful! I'm starting to think that it's probably too late to do kale this year then (I'm in the SF bay area) and maybe I should think about doing it in the autumn. However, we still have lows in the 40s right now and even my sweet pea seedlings are growing super sloooowly. Perhaps it's still ok to do kale?

When mine bolted, I just kept it. I picked off the flowers, and it kept growing. It was still sweet when the frosts came. The flowers are edible as far as I know anyways.

ralleia - let them blossom and cook the shoots like broccoli raab, by then your new greens may be about ready to start harvesting.

RabbitRabbit - it can't hurt to put some in now, but save the bulk of your seed for a fall/winter crop. You can cut the bottom leaves off of your solanaceous plants and seed the fall kale underneath. After the nightshades stop producing, just cut the stems at the soil line and let the kale take over. Plan to start seeding about a month before first frost. You can do the same with spinach and peas for fall, too (a few weeks earlier for the peas, they're always a gamble in fall).

Lettuce can be bitter when it flowers/bolts.
I grow red kale some Winters for color in salads.
I grow collard year around & have them on the 4th of July.
I never had bitter kale or collards.
You should try it & tell us what you think.

Thanks so much everyone for the great advice. I just got some Russian Red kale seedlings at the farmer's market, so I'm going to put them in and see how they do. They are so pretty anyway that I'm growing them in between flowers as part of an edible landscape. If it gets hot, I'll just harvest them small!

Ralleia, you should let some of your russian go to seed, it's a fabulous self-sower and does not cross with weeds or mustards like most breeds of brassica do.

In USDA zone 9 you might be able to grow your kale all summer - especially if you have a space that gets afternoon shade(it doesn't need full sun in CA). I grew it year round in z9/Sunset14.

I found the easiest way to cook it is to sliver it in long strips and throw it in the water with pasta - for kids, even the sweetest kale may be a push if it's cooked up just as a side green - sneak it in first :-)

The kale I grew the most came from a combination packet from Renee's Garden seed years ago and I'd saved that seed. Green with white and flattish, not highly curled. Can't really find it easily these days so I'm trying her Portugese kale (supposedly sweet and more heat tolerant, but this is my first year so can't say yet).

Here is a link that might be useful: my blog