These are some sort of containers, right? Best I could find online.is linked below. Honestly never heard of anyone using them as I think they are relatively new. But they appear to be somewhat like the Earthboxes which have been around for decades. So yes, as with Earthboxes the plastic cover is supposed to remain in place throughout the season to prevent rapid evaporation of the soil moisture.

Of course that all depends on where you live (which you didn't indicate), how hot it gets there, how often you find you need to water and feed, the color of the plastic cover, etc.

But it appears that once planted you can't remove the cover anyway without damaging the plants.

As for limp lettuce on hot days? How hot are we talking about? 70-75 degrees - not really. Not if you are maintaining the water level in the planter and it is working correctly.

95 degrees? Yes since lettuce is a cool season crop.

Please include your location or at least your gardening zone in your posts. It makes a BIG difference for the answers. :)

Dave

Here is a link that might be useful: City Picker planter

Thanks for the reply. Im in Orange County, Ca. The mulch cover is black. Since my City Pick planter is self watering, just like the Earthbox, I top it off every day. If there's too much it'll drain through the over flow then retain water. Soil im using is the Miracle Grow organic potting mix. I have yet to add in EB Stone organic vegetable food.

The last week temps have been around mid to high 80s. From the research I've read that the water evaporates from the plants cells causing the limp look. Once night comes around or early morning they look great again.

Might want to do some reading about the problems associated with using granular organic fertilizers in containers, especially small ones such as this. Since there is no soil food web, no beneficial bacteria or microorganisms to convert the supplements to a useable form for the plants, you need to either add the bacteria and other needed soil organisms or use liquid fertilizers and you have to feed them frequently. .

Gardening organically in a container is a very different ballgame than organic gardening in ground.

As for the black cover rather than remove it just spread some mulch on top of it to reduce the heat.

Dave