Lettuce woes

I have a large vegetable garden, and a produce stand by the road. I grow a lot of things, but one thing I can't seem to grow well is lettuce. I water it daily, and have given it compost. But even if I go out first thing in the morning (which I understand is best) and pick some, it has a bitterness to the taste; and I can see when I break open a major vein, some of the white juice I associate with lettuce bitterness. I do have a west-facing slope in the garden, so afternoons can be quite hot here. There is a large forested hill to the east, so morning sun comes late. My native soil is quite sandy, but I have been building it up with compost for many years. Most other stuff grows pretty well. I'm in Michigan, in zone 5. What do you think is the problem here?

 

I would say the lettuce is too old and should have been harvested earlier.

Some of my lettuce and mesclun are setting flower stalks (bolting). I have to be careful to only take the younger leaves. Even though the older big leaves look good they have the bitter taste of old age.

 

Thanks Dane, but this is even happening now at the start of the season on plants that are not fully grown.

 

Have you had hot or dry weather? It only has to be in the mid 70's or above for the heat to become an issue, especially if they are low on water. Here in NC the season is coming to an end for growing outside though I extend it a bit by shading the plants.

It could be the soil. I once made the mistake of growing strawberries after I mixed peat into the soil. If you can imagine sweet strawberries with the funk of a peaty Scotch whiskey.

 

What kind of lettuce.
Perhaps try a different one.

 

I have several varieties, and all are this way. I guess next time I'll stick to varieties that are adapted for warm weather.

 

Pick sooner!!! I pick long before the leaves achieve their final size.

 

Don't know where you live but June 7 is not the start of the season. Lettuce is an early spring crop. Once it gets warm and the growth slows, lettuce gets bitter.