Brutal heatwave 7/06/18 in Socal

[WaterFowler]

My Lemon Zest seemed to love the heat wave. And we are the 2nd hottest area in the nation next to Death Valley. The town I live in is literally called "Thermal". My LZ was only holding on to one fruit but looks like it will keep it til maturity. Picture is taken a top a step ladder about 10 days after heat wave. It burst out with growth right after it hit at least 122 degrees.

Waterfowler: with no damages at 122F, I wonder if it was high humidity at yours? My area was 115F but dry and all of my mangoes had burned leaves and fruits. Just a month ago I said the LZ that Simon gave me the cuttings finally held about 5 larger fruits -- about 2 to 3" long -- and I thought I would have LZ to eat this year, but the heat dropped them all; even Glenn couldn't hold any fruits. I think if I had covered the trees with bed sheets then perhaps some fruits could survive.

We've had terrible humidity the last few days but during the heatwave it was very dry I believe. You can see the shade cloth right behind the tree which I've used in years past and up to this spring but I did not use it this time. It seems like the cloth just damages the new tender growth. Like DesertDreamer said above, I deep water my trees with a hose, not 3 or 4 times during spring, but every Sunday once temp start climbing above 110 degrees and stay there. Ranging from a couple of minutes to 20 minutes depending on the size of the tree. Also like DesertDreamer suggested I use accompanying trees/plants next to a lot of my subtropicals to protect them. Namely moringa and castor bean plants. You can see in the photo from my previous post a castor bean leaf off to the right. Their leaves are literally cold to the touch during the heat. Seems like young trees thrive around them.

The LZ and the "manilla" trees at my renter's house are the only mangoes of mine that see full sun most of the day. The other ones are still young and are semi protected underneath shade cloth or underneath larger trees/plants. My Coconut Cream and a CC seedling seems like they fared the worst under the heat wave but nothing major. It was brutal though. When I saw numerous guavas, which are normally tough as nails, with dangling limp leaves it concerned me greatly.

[simon_grow]

It’s sounding like we AZ growers need to pass along a few tricks to our so. Cal brothers.  In no particular order....50% ( min) shade cloth on the west side for at least the first summer ( maybe two depending on growth rate).  Larger root mass= better survival rate, so I mostly plant 7 gal trees, minimum.  IF you have good drainage, mangos can handle a lot of water.  If not, they rot out during heatwaves when you water every two days.  I do DEEP watering three or four times in the spring to encourage deep rooting.
 I grow a variety of silica accumulating plants to use as mulch, Vetiver grass topping that list.  I also spray a few times in the spring to make sure the plant accumulated enough silica to withstand the heat.  I also have worked to develop a microclimate that provides shade and humidity.  Fast growing trees that can be chopped down in a few years are a great way of accomplishing this (morniga, tipu, ash,jacaranda, etc).
Plants have to be in good shape by the time June hits.  I will gladly sacrifice a little growth in the spring by not pushing fruiting too young in order to have a healthier tree with better caliper growth.
I dig planting holes a year in advance and provide a lot of drainage via gravel, stones, pumice, etc. mixed with my planting mix.  This allows compensation for settling, as well as establishment of fungal populations which can help augment roots.  I will also will plant in Fall and baby plants thru winter if they are slower growing varieties.  That gives a bit more root mass by the time June hits the next year.  I can more easily compensate for our cool temps than I can for our brutal, dry summers....Fast growers like LZ and Peach Cobbler always do better in our heat than slower varieties.  Dig BIG planting holes so roots can spread as fast as possible. 
As long as the trees are in good shape during heat, I continue to fertilize lightly with fish emulsion (50% of recommended rate).  This seems to allow for rapid recovery once our temps cool a bit and humidity rises again.  If not in good shape, focus on moisture management and just getting the tree to survive.  Danger zone is >105 and/or winds.  I ignore crispy leaves and any crisped new growth and focus on keeping soil moist, not soggy, and do a quick hand misting in the AM and evenings to provide some relief to the younger plants.
Finally, I find a bit of amino acids and maybe a little superthrive seems to help avoid the worst damage.  Absolutely avoid strong fertilization during heat.  Trying to help by adding too much ‘stuff’ to your regimen is counter productive.
I hope this helps people.  We in AZ are in uncharted territory when it comes to growing mango, so I hope my observations can help others avoid the 10 years of mistakes I have made.

Thanks for the great info Dessert Dreamer!

Simon

[Lionking]

It’s sounding like we AZ growers need to pass along a few tricks to our so. Cal brothers.  In no particular order....50% ( min) shade cloth on the west side for at least the first summer ( maybe two depending on growth rate).  Larger root mass= better survival rate, so I mostly plant 7 gal trees, minimum.  IF you have good drainage, mangos can handle a lot of water.  If not, they rot out during heatwaves when you water every two days.  I do DEEP watering three or four times in the spring to encourage deep rooting.
 I grow a variety of silica accumulating plants to use as mulch, Vetiver grass topping that list.  I also spray a few times in the spring to make sure the plant accumulated enough silica to withstand the heat.  I also have worked to develop a microclimate that provides shade and humidity.  Fast growing trees that can be chopped down in a few years are a great way of accomplishing this (morniga, tipu, ash,jacaranda, etc).
Plants have to be in good shape by the time June hits.  I will gladly sacrifice a little growth in the spring by not pushing fruiting too young in order to have a healthier tree with better caliper growth.
I dig planting holes a year in advance and provide a lot of drainage via gravel, stones, pumice, etc. mixed with my planting mix.  This allows compensation for settling, as well as establishment of fungal populations which can help augment roots.  I will also will plant in Fall and baby plants thru winter if they are slower growing varieties.  That gives a bit more root mass by the time June hits the next year.  I can more easily compensate for our cool temps than I can for our brutal, dry summers....Fast growers like LZ and Peach Cobbler always do better in our heat than slower varieties.  Dig BIG planting holes so roots can spread as fast as possible. 
As long as the trees are in good shape during heat, I continue to fertilize lightly with fish emulsion (50% of recommended rate).  This seems to allow for rapid recovery once our temps cool a bit and humidity rises again.  If not in good shape, focus on moisture management and just getting the tree to survive.  Danger zone is >105 and/or winds.  I ignore crispy leaves and any crisped new growth and focus on keeping soil moist, not soggy, and do a quick hand misting in the AM and evenings to provide some relief to the younger plants.
Finally, I find a bit of amino acids and maybe a little superthrive seems to help avoid the worst damage.  Absolutely avoid strong fertilization during heat.  Trying to help by adding too much ‘stuff’ to your regimen is counter productive.
I hope this helps people.  We in AZ are in uncharted territory when it comes to growing mango, so I hope my observations can help others avoid the 10 years of mistakes I have made.

Thanks for the advice DesertDreamer,
We have some triple digit weather forecasted for our area of So.Cal starting this coming Monday the 23rd lasting thru Thursday the 26.   Hottest days being Tues and Wed. @ 104.
Your advice came at the perfect time.

[behlgarden]

Out here in Riverside I have my trees covered with 30% shade cloth (younger trees) and I thought they held up well to that heat wave. But over a couple days they started showing the damage black sun burns on stems, roasted new growth, shriveled and dropped all fruit and now my little Mallika looks like it may be dead.

That said it looks like the best may have kicked my lancetilla that has sat around and done nothing for almost a year into growth.

Should I leave the shade cloth up the rest of the summer or just let it best down on them?

My manilla in the ground with no protection got roasted too.... But not much worse than the others

I wasnt here when the brutal heatwave occured & i lost the mangoes i have on sweetart and some minor leaf damage.



However, my 3 gals mango i received a month ago from florida took the brutal heatwave like a champ considering they get more sun than of the sweetart.

I noticed one thing in my yard post heat wave:
1. Mango plants that were holding fruit or blooms/fruit took a beating. I am talking about grafts and branches drying and dying 6-8 inches.
2. Mango plants that were young OR not holding any fruits/blooms, were unscratched  or very little leaf tip burn. More importantly, plants that withheld without damage were in the hottest west side that also gets radiant heat reflected from west wall of my house.

I ask others to review and confirm this. I confirmed this with another fellow Gardner and it was exactly his case too.

[WaterFowler]

So 2 weeks after the heatwave here's what some of my plants look like(well since it's been 103-114 every day since, pretty much every day is a heatwave here lol).

Banana chose to flower at wrong time. All the bottom fruitlets turned black shriveled up and died. Damage to top of plants too.





Pink guava fruits yellowed on top. Not too much with white guavas.



Haysa Sapodilla which had dangling leaves during day seemed to recover fine.



Newly grafted LZ, Coco Cream, and Sweet tart mangoes under full tree canopy protection are doing fine.





Small sweet tart under full tree canopy protection with new growth. Although the ants seem to love sweet tart above all else and mess up the new growth a little.



Unprotected 4 year old LZ with lots of new growth after heat wave and still holding its lone fruit





Young coco cream somewhat damaged to leaves that stuck out of shade protection.



Finger lime significantly yellowed by sun. Still held on to fruits though



Guamuchiles I have planted for future canopy protection absolutely bursting with new light green growth.



Baby jackfruit and mamey sapote planted next to banana with partial canopy protection did just fine (but will probably die this winter).



Best of all. My little Cotton Candy mango in container I bought from TT, which had done nothing in the 2 months since I received it in the mail, finally started to put on growth after the heat wave.

[spaugh]

Nice plants.  Impressive especially for the desert.  Are you growing watermelons?  I got some desert king watermelons growing.  They are really good and will take the desert heat no problem.

[Bush2Beach]

Desert Dreamer dropping serious knowledge far beyond heat wave talk.
Thank you. Please keep it up.

[FruitFool]

Out here in Riverside I have my trees covered with 30% shade cloth (younger trees) and I thought they held up well to that heat wave. But over a couple days they started showing the damage black sun burns on stems, roasted new growth, shriveled and dropped all fruit and now my little Mallika looks like it may be dead.

That said it looks like the best may have kicked my lancetilla that has sat around and done nothing for almost a year into growth.

Should I leave the shade cloth up the rest of the summer or just let it best down on them?

My manilla in the ground with no protection got roasted too.... But not much worse than the others

I wasnt here when the brutal heatwave occured & i lost the mangoes i have on sweetart and some minor leaf damage.



However, my 3 gals mango i received a month ago from florida took the brutal heatwave like a champ considering they get more sun than of the sweetart.

I noticed one thing in my yard post heat wave:
1. Mango plants that were holding fruit or blooms/fruit took a beating. I am talking about grafts and branches drying and dying 6-8 inches.
2. Mango plants that were young OR not holding any fruits/blooms, were unscratched  or very little leaf tip burn. More importantly, plants that withheld without damage were in the hottest west side that also gets radiant heat reflected from west wall of my house.

I ask others to review and confirm this. I confirmed this with another fellow Gardner and it was exactly his case too.

Hi, Behl,

I have about 5 small mango trees, none holding fruit and I dont see any damage due to heatwave.

Thanks,
FruitFool

[behlgarden]

Glad to hear fruitfool.
Let's see if other people can also confirm this

[simon_grow]

My Lemon Zest on Florida Turpentine rootstock is holding fruit and begging out and suffered no damage on its leaves or Fruit. A few recent grafts on this same tree has fried to a crisp but grafts that were put on several weeks before the heatwave actually pushed out vigorously.

I have a small double rootstock Sweet Tart tree that was holding three Fruit and all three Fruit cracked in half but there was no damage to the tree or leaves. All three Fruit are still hanging and I can see that there is no embryo in these three Fruit. I have noticed that the Fruit with atrophied seeds/embryos are more easily damaged.

The heatwave damaged my recently grafted scions the most.

Seedling trees that are not grafted are pushing vigorously.

Simon

[simon_grow]

I just heard on the radio that there is another heatwave expected next week.

Simon

[wslau]

I just heard on the radio that there is another heatwave expected next week.

Simon

Wednesday 7/25 will be the hottest, but temps won't go higher than 105F for those in Los Angeles area zones 10a and 10b.
So it's definitely not as bad as 7/06 for most.

[SoCal2warm]

Mangosteen got fried

[WaterFowler]

Here we go again.

Today 118
Tues 118
Wed 120

I think it only got to 118 once last summer. That will be 5 days 118 or over before the end of July. Sigh.

[WaterFowler]

I think this heat wave will be worse for us at least. It might be a degree or 2 under the peak of the heatwave 2 weeks ago, but the extreme heat will last much longer.

[spaugh]

That sucks.  Good luck out there in the desert.  Im about to go thrw some burlap shades up over some of my small avocado trees.  Should have paited them this weekend but didnt have time. 

[greenman62]

Here we go again.

Today 118
Tues 118
Wed 120

I think it only got to 118 once last summer. That will be 5 days 118 or over before the end of July. Sigh.

wow, and i was complaining about 97 yesterday, and 95 today.
ive been out spraying water on the leaves and mulch layer.

watch out for black containers !!!
they suck up  that heat and fry the roots.
OK if its an edible root and your hungry i guess...

someone said humidity keeps the temps down ?
its 61% today, and often is over 80%. (90% in the morning)
i was out yesterday for 40 mins at 8:30am, before 9am i was soaked in sweat.
full clothing change including socks.

[behlgarden]

Hit 106 already and it's only 1 pm. New growth will get fried.

[gozp]

My sensors r currently reading 114f in the front with 25% humidity.

[behlgarden]

I have 6 sensors all around my yard and a Pro weather station. It gives me very accurate localized temps. At 106 it's 29% humidity. Which is unique as when we get to 100 our humidity dips to single digits.

[JF]

97F 45% humidity and it's not even September the hottest month of the year. Wednesday's forecast 105F second heatwave this month.

[zephian]

My temps arent as extreme but very dry.
Gotta figure something out before I lose more of my cherry tree. May put it under a persimmon for a while...

[behlgarden]

Hit 109 already.

[WaterFowler]

Hit 106 already and it's only 1 pm. New growth will get fried.

A lot of the new growth on big LZ is looking bad and it's only day one of the 4 day heatwave. I might as well pull over the shade cloth or it will all get fried by Thursday. Guavas doing OK so far. Sapodillas all look rough, bananas too but I I can't do anything for them.

Plus it seems there's a fire every other day within sight for the last month or so.

[WaterFowler]

Every time I check accuweather it keeps getting hotter