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heat tolerance of kale

Posted by kawaiineko_gardener 5a ( on
Sat, Feb 5, 11 at 16:25

I know that with collard greens, they can be grown in hot months and in cold months (a light frost will improve their flavor) and in hot months they won't bolt.

I'm basically wondering about kale. Can it be grown in summer as well, or will it bolt due to the heat, and will it's flavor be horrible if grown in hot weather?

Essentially I just want to know if the growth habits of kale are similar to that of collards; if it's something that can be grown year-round like collards, or is strictly
a cool weather vegetable?

Follow-Up Postings:

RE: heat tolerance of kale

Kale and Collards are both Brassica oleracea acephala group. As such, they are true biennials. Neither will bolt to seed during its first summer unless something extraordinary happens to it, or perhaps unless it's a genetic fluke of some sort.

However, just as with collards, the flavor tends to be too strong for most people during the hotter months of the year. Flavor moderates ("sweetens") with cold.

I'm sure that it could be grown in a manner which would help to mitigate or at least moderate the effects heat has on the flavor - growing it fast and rich, with a lot of moisture and some mid-day shade would probably help. You would probably just need to experiment with it to see if that would give you the kind of results you're looking for during the warm months.

RE: heat tolerance of kale

I grow my kale year round, but I don't typically eat it in the hot summer months. I start inside and plant in the garden Mid-March, then harvest until about Mid-June or until the weather gets hot. Come fall, I start harvesting again, especially after the first frost hits. They usually have lots of leaves by then and they taste fantastic. The dino kale was amazing this year. (As a side note: I really push the season by putting things in early)

As denninmi said, they will not bolt.

Hope that helps,

RE: heat tolerance of kale

I like the flavor year-round and harvest them throughout the summer. Young kale plants are flavorful and tender, so you might want to succession sow (plant a little every couple of weeks) and pick leaves when the plants are 6 to 12 inches tall, letting some grow to maturity for the fall and early winter and thinning the rest.

Kale is quite hardy and you can put the seedlings outdoors under row covers very early in spring.

RE: heat tolerance of kale

Is it too late to plant kale seeds outside in zone 5? I'm in NW IL and the weather is still pretty cool here--frosts every night-- but will be warming up quickly. Just too wet and cold to dig til now. If I do plant now, when would I be able to harvest and should I leave some plants til fall? I have never grown kale in the midwest before.

RE: heat tolerance of kale

Should be fine; you could even wait a couple of weeks, since seeds germinate slowly in cold soil.

RE: heat tolerance of kale

  • Posted by jolj 7b/8a-S.C.,USA (My Page) on
    Tue, May 3, 11 at 15:30

I know so little about zone 3,4,5,6, but here in South Carolina zone 7b/8a my collards bloom(bolt) every year & I have plants that are 4 years old.
I let them go to seed last year, tiny plants every where.
All my broccoli,brussels sprouts,cauliflower,collards,kale,lettuce,mustard,radishes,spinach & turnips, will bolt if I do not use them.
I have tried Kale & parsnips only once, so far.

RE: heat tolerance of kale

My kale and collards would grow through summer, but I would have to fight the harlquin bugs to keep them. Instead, I pull out all spring brassicas when I see the first harlequin bugs, and manage about a month before I start setting out the fall seedlings, under row covers.

This late, I think chard is a better choice for planting because it keeps its quality through hot weather and doesn't attract bugs. Wait and start fall kale in July.

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