bitterness in lettuce and salad leaves

[Karen]

Hello Charles,

I am a HUGE fan of yours and have several of your books. Because of your books, we were able to create our dream garden.

Now… I have a question that I hope that you could help me with. I can never understand why after a while (within a month or 2)… the leaves of our lettuce or salad gets bitter. I have just watched a video of yours and that you have suggestions to prolong the lifespan and harvesting periods of salad and lettuces by plucking the outer leaves. The only problem is that they are terribly bitter.

I look forward to hearing any suggestions… I am constantly dumbfounded by this problem.

cheers
Karen

[charles]

Hi Karen and thanks for your comments.
What a shame about that bitterness. One other person had this problem and they are on sandy, light soil and it was mostly in warm weather, so lettuce were feeling less comfortable, leaves were drier and maybe then the bitterness is dominant.
As lettuce ages, its leaves do grow a little more bitter but interestingly I fond that leaves off 7 month old Grenoble Red, sown September and planted October undercover, taste superb. So it may be more a soil and summer thing. Try Maryvilla di Verona in summer (Seeds of Italy mainly).

[Karen]

Hello again,

Thanks for replying… much appreciated. I am actually living in Germany (about 90km south of Berlin) I do believe our temperatures are somewhat quite similar to that of England.

The lettuces and salad leaves were grown in raised beds with loads of compost (well rotted horse manure and composted materials). Can and are they supposed to be grown in direct sunlight or better in shaded areas? I remembered clearly too we had the same exact problem with the bitterness when we were growing them in New Zealand.

Would you also be able to tell me how long the harvest period of your lettuces before they got bitter? I do believe too that there are salads/lettuces for different seasons…. e.g. summer and winter lettuce varieties

I do own a copy of your Winter Vegetables book and Salad Leaves for All Season. I guess I should have another look at them… however I never was able to find anything about the causes of bitterness in lettuces. Although I have read somewhere in the internet that lettuces are bitter when a thick white liquid oozes out when plucked. Due to the maturation of the plant .

My apologies for ranting on. I am actually curious and surprised that not many people have my similar problem. I am also hoping to be able to provide a constant supply of salad leaves to our family restaurant.

Thanks again for taking the time and effort to reply to my question.

cheers!
Karen

[charles]

Interesting.
I have noticed that the first pick is sweet, then bitterness slowly increases over 10-11 weeks from the first pick, in spring and summer, my main seasons for growing lettuce.
I think that the closer a lettuce is to flowering, the more bitter its leaves. But in moist compost and favourable weather, leaves are sweeter. In full sunlight as I hardly ever grew lettuce in much shade.
So your experience slightly contradicts that and like so many things, its multi faceted.
I would try out some different varieties for one thing and grow lots of other ingredients too like pea shoots, spinach and sorrel, but I expect you are already doing that.
Good luck with the restaurant.

[Karen]

Haha… 🙂 guilty as charged.

I am growing quite a fair variety of salads and spinach… from what I can gather from your last message is “moist compost” might be the reason?

All or most of my plants are grown in raised beds and I hardly ever water them after a hard watering for a week or 2 to getting them settled in as seedlings. Perhaps I need to constantly keep the salad and lettuce beds moist and wet?

I will experiment and try a batch with constant watering and another without as well. I will also attempt to plant some in direct sunlight and shaded areas. I hardly water my plants as the beds are filled with compost and I have always believed in plants searching deep into the soil for water, unless there is a really bad dry spell and that the plants look like they really need help.

In any case… thank you for your thoughts and input and will try out the above experiments.

[charles]

Maybe I overdo the “water less” advice but they are still salads in summer [caption id="attachment_31671" align="aligncenter" width="500"] The Lollo Rossa is better, and in front are the new endives[/caption]
and their roots are not as deep as most other vegetables.
Good that you experiment!
And maybe the deep-rooted bitterness is full of trace elements.

[charles]

PS adding media, I struggle

[bluebell]

Hi Karen I have a light sandy soil and do find that overall quality of salad leaves was much worse in raised beds than in the ground. I have just removed the last of my raised beds, as they are just too dry to produce good crops of most things.
I know that sounds a little odd when half of UK has had significant flooding, but we are on top of a hill on the edge of chalk Downland in the dry south east.

[Karen]

Yikes!

Hello bluebell…

We love our raised beds… we have 6 beds with asparagus growing in them and I swear I have never watered them after having established them in the beds with loads of compost and rotted horse manure.

I am going to try to water the salad and lettuce a little more often now and try our the experiments as mentioned above.

We created our raised beds as I didn’t have the patience (I would have gone stir crazy waiting!) to wait out to weed/mulch out for about a year as suggested by Charles. And it´s a whole lot easier to mow between the beds.

Can´t wait for the weather to warm up! My fingers are itching to go now!

[Karen]

Thanks Charles for the pic… I went through several of your videos and I am so amazed by how clean your soils are especially those that aren’t in raised beds!

Have you encountered any differences between growing lettuces and salads or even other types of veg in raised beds and non-raised beds?

[charles]

Main difference is carrots which grow longer and pull more easily in higher beds, otherwise quite similar.
My back prefers raised!
And how raised is raised? I have some beds 2in above path level, some 4in and some 6in. I think that when people say ‘raised beds’ they imagine wooden sided, 6in high beds.
My preference is 3in high and no sides, and everyone is different, varied soils etc as Bluebell notes.

[bluebell]

Aah on that definition I still use raised beds! mine are now just mounded rather than with 6 inch wooden sides 🙂

[Karen]

Most of our beds are about 6in high too…. with the exception of our very first asparagus bed at 13inch! Gonna definitely try out our remaining patch with no sides….Cant wait to get started! 🙂

[Karen]

Hey Charles,

I have been walking around our salad and lettuce beds and tasting the leaves and I do strongly believe certain varieties of lettuces gets bitter a whole lot quicker than others. I have been comparing the tastes of all the lettuces from the 1st sowing/planting in Spring. It seems that the “greener” leaf varieties are a lot less bitter than those that are a mixed of red and red/green. I know you have mentioned in your postings too that reds tends to be bitter. The only good thing is they add colour to the mix! I honestly can´t handle bitter leaves! Those growing in the shade are also a lot less bitter. Think it has a lot to do with how much heat and moisture the plants have taken in.

Several of them are also beginning to flower.

I guess it is time for me to pull the Spring plantings out and patiently wait out for the 2nd sowings to get a little bigger in their cell modules now.

[charles]

Yes I agree for sure, and your heat makes it worse. We stop picking when they go up and have leaves now from a sowing on May 19th (two before full), I hope your new sowings start soon, sow again mid July for autumn.

[Author]

Posts