Growing lettuce in hot weather

[David J]

I'm awed by the lettuce growing I see in the pages of the AP websites. Many AP'ers are in hot climates in Australia. Can you grow lettuce on a raft system when the outside temps are 38 degrees? What are the temperature ranges for growing lettuce in an AP system?

[Ravnis]

I've tried it, but have not had luck with it when it is that hot. Romaine is probably your best bet. My most productive plant growth periods is fall, winter and spring.

[GaryD]

Hi David,

I'm awed by the lettuce growing I see in the pages of the AP websites. Many AP'ers are in hot climates in Australia. Can you grow lettuce on a raft system when the outside temps are 38 degrees? What are the temperature ranges for growing lettuce in an AP system?

Many varieties of lettuce tend to bolt in hot weather. Locate some local hydroponic growers in your area and see what they're doing.

Water temperatures are certainly more stable in raft systems......and that translates into lower root zone temperatures - a critical growth consideration for lettuce.

Gary

[DaveOponic]

They grow all types of lettuce in Hydro here in brunei. they use raft systems and evaporative cooling in shade houses with huge blower fans to keep the temperatures down. I have grown lettuce but with varying success. I haven't given up and will try some kind of cooling system to grow it undercover. I reckon indoors with AC would be the best way but my wife doesn't like the idea of bringing the plants and fish into the house!!

[Damon]

while in hawaii we experienced the bolting effect of lettuce in high temps. really if you're rotating your crop fast enough a general percentage of your lettuce will be fine, if not a bit wilty... really there was only one unruly lettuce that bolted a full week earlier then any other variety of lettuce even started showing sign of bolting... i believe it was the red lettuce with the name "lolla" something... th ebiggest problem you're going to have, if you're growing commercially, if wilting... other than that again if you're growing commercially, if you lettuce is staying in your raft system for more than 3-4 weeks (if your sprout was about an inch (2cm) tall when entering the raft) you're letting it sit too long. the lettuce will tend to go bitter if it sit long than 4 weeks, but its managable till the end of the 5th week... any later than that and it'll start to get nasty.