Temperatures that interfere with pollination

[RobinB]

This year, as usual, I started 36 plants in Walls O' Water in mid-April. I usually remove the WOWs in June once it seems safe to do so. This year, I'm leaving them on all season. Does anybody else do this? A local master gardener swears this helps the plants beat the heat. He says it's like evaporative cooling. So far, so good. In yesterday's 103° heat, these larger plants did fine and didn't seem to need extra water. I'm sure this method wouldn't work that well somewhere where it is more humid, but it's so dry here I though I'd try it. The jury is still out as to whether this will actually help them set fruit in extra hot conditions. Pervaya Lyubov has 15 or so fruit inside the WOW, and Ananas Noir, Malachite Box and Fish Lake Oxheart all have several fruit down inside, but most have fruit and blossoms outside (above) the WOW, so who knows if the roots being cooler will help with fruit set. I got a lot of blossom drop yesterday, but I think it was due to the hard rain more than the heat.

Here's my front garden in the late afternoon shade. Thank God for trees! Yes, that is an old sink over on the right. It's going to get some tumbler tomatoes planted in it once this heat breaks.

Robin

[Keger]

Originally Posted by Worth1

Barb there are no set temps for blossom drop.
As anything else it depends on the variety.

Smaller fruited at my place will set at way over 95 degrees.

Some large fruited play out in the mid 80 degree temps.
I have pretty much gone to planting early determinate tomatoes.

It is a total waste of time to plant anything else.

Worth

Again, you are right my friend. 104 here today, I was happy selling my last tomato bucket this morning.

Purple hulls and Okra...

Till winter..

[Salsacharley]

Robin,

You've got some big raised beds there. How big are those?

Good luck with your WOW's.

Charley

[RobinB]

The big bed is 12 feet square. The only reason it is that size is that the previous owner of this property had built a raised bed and used 6" PVC stacked, wired together and spray painted! It was really, really ugly. We took the path of least resistance and built a wooden bed (with those metal brackets you can buy) just slightly larger than what was there. Wasps had made some nests inside the PVC... that was fun! All the other beds are 4' square. Perspective in the photo is making it look like it's all one bed.

[Worth1]

By the way this year I had more tomatoes than I could eat so we gave our neighbor Alexandra from Chile some.
She was tickled pink.
The plants are coming down and okras going in.

Worth.

[livinonfaith]

Robin, that is really a neat trick with the WOW!

I understand how they protect from the heat of the day, but don't they soak up heat during the day and release it to the plants at night? It seems like they would kind of even out the extreme temps of the the day and night. (Making it several degrees cooler in the heat and several degrees warmer in the night.) I'm just wondering because everything says that those cool night temps are so critical to fruit set.

Maybe the shade of the leaves and the white color of the WOW helps shade and reflect the sun's light so the the water doesn't really absorb that much of the heat.

If that's the case, I wonder if a slightly reflective material wouldn't keep it even cooler? (As long as it didn't reflect enough sun onto the bottom of the plant to scald it.) That wouldn't work as well for warming them up in early Spring, but it might be better for the Summer.

I wonder if you tried wrapping a few with a reflective surface, (maybe even something as simple as thin tin foil, (with the duller side up) if that would make any difference?

Or is that just crazy?

[dice]

Near Reno, NV, they have cool nights, even in summer.
(Big day/night temperature swings.)

[RobinB]

Dice,
Cool nights? Not lately! Thank God we are through with the extreme heat and severe thunderstorms we've had for the last six or seven days. We've been setting new highs (15-20° above normal) every day for the last week, and then having severe thunderstorms (hail, lightning, wildfires, rain, high winds, and flooding) somewhere every afternoon. We never got any hail, but we experienced everything else in the past week. Today, my cel phone, which is set to give me an alert every time the National Weather Service issued a watch or warning, just kept going off. There were over a dozen warnings today alone. I don't think I lost anything though. Watching my poor plants out there in high winds, covered in mud, lashed down to bamboo poles is hard, but there's nothing to do but watch. Now we get 7-10 days of mid-90s with mid-50s at night. Much more comfortable!

Livingonfaith,
I didn't know that lower night time temps helped with fruitset... I just went outside and the temperature is 71.6 still! The WOWs felt cool to the touch. During these sizzling days they feel very warm, but they're cooler than 105° that's for sure. Whatever is happening, it's working. Those plants that are setting fruit are really setting a lot of fruit, but some still have fruit only inside the WOWs. Some continue to just drop blossoms, but only a few don't have any fruit yet. It's an interesting experiment!

[dice]

90F-50F seems like a significant swing to me, but I have not
actually lived there, only passed through a couple of times in
August. It did not seem like it was warm enough at night to
interfere with fruit set, although the summertime days could
get that hot.

I remember a truck driver telling me about trailer homes
that had not been anchored down yet out there west of town
along the freeway rolling along beside the road in a wind storm.

[RobinB]

Today, 93°, last night 52° that's normal for here. I don't worry until the nighttime temps get below 40. Reno, because of the topography is a freakin' wind tunnel. Lots of rebar and lashing things down. It works though!