So. Much. Water.

[ahosey01]

I have several species of non- desert (Mediterranean, mostly) palms in the yard, along with several broadleaf trees - many of them eastern deciduous species.

It has been 110+ on and off for over a month now with sub-10% humidity and no rain at all. I have been watering constantly.  Chamaerops & P. dactylifera and canariensis almost every other day, Bismarckia and P. roebelenii every single day.  Also have a Eucalyptus I been watering close to every day.

This feels like overkill!!  But I notice definitively they are doing better on this schedule during this period of heat than they were on a less frequent schedule.

What are the weather benchmarks I should use to decide when to cut back again?

[ahosey01]

Should also note we haven’t even had a cloud in months. Full blazing murderous Sonoran desert sun 100% of the time.

[Dimovi]

You should not have to water every day unless maybe the soil is sandy and the plants are not established. You can mulch to slow down evaporation and to keep the soil cool and insulated from the sun. 

Dactylifera has insanely long roots as most desert/Mediterranean palms.  The roebelenii is probably the most needy.

Dig into the soil and see how far down it is dry.

[ahosey01]

8 hours ago, Dimovi said:

You should not have to water every day unless maybe the soil is sandy and the plants are not established. You can mulch to slow down evaporation and to keep the soil cool and insulated from the sun. 

Dactylifera has insanely long roots as most desert/Mediterranean palms.  The roebelenii is probably the most needy.

Dig into the soil and see how far down it is dry.

I should be specific, I suppose. The two I water every day are really almost every day.  I use a soil probe and if the soil isn’t wet, I water. This equates to around 5 watering per week.

With the Bismarckia, I have noticed that if I do not water at that rate in this heat, the spear barely moves from day-to-day, and the center of the oldest fronds (where the leaf blades reach the petioles) starts to dry out and get crispy, causing the base of the lead blades to break.  With the roebelenii, if I do not water at that rate, the fronds start to droop and the palm is noticeably shorter on dry days.

Keep in mind, it’s been 110+ on and off for over a month and for probably 10 days straight now.  Typical humidity is 3-8% during this time and both of these palms are getting probably 10 hours of direct sun per day.

Edited August 18, 2020 by ahosey01

[Dimovi]

Are the plants established? Once established the roots should be so deep that moisture sensor won't indicate much. Deep, less frequent watering stimulates root growth deep into the ground. Here in Austin I water once or twice per week and the highs in July have been well into the 100s, but humidity is higher at around 30% during the day. I probably would not water so often if I did not have free water. The biggest difference is probably the soil. Clay and loam can retain moisture for much longer than sandy soil.

[Chester B]

On 8/16/2020 at 11:17 AM, ahosey01 said:

several broadleaf trees - many of them eastern deciduous species.

Cut these down - what a waste. 

The same thing happened here, they brought all the eastern species and by midsummer they start changing color and dropping their leaves.  Such a lack of imagination and ignorance when there are so many more interesting climate adapted trees we can grow in our climate.  I have removed the Norway Maple (worst tree ever) and Red Maples from my property.  

[ahosey01]

3 minutes ago, Chester B said:

Cut these down - what a waste. 

The same thing happened here, they brought all the eastern species and by midsummer they start changing color and dropping their leaves.  Such a lack of imagination and ignorance when there are so many more interesting climate adapted trees we can grow in our climate.  I have removed the Norway Maple (worst tree ever) and Red Maples from my property.  

I actually like them.  The reason I like them is because my kids can play outside during the dead of summer because the shade is so dense.  With a lot of desert native species - ironwood, Palo Verde, acacia - they don’t really strictly provide shade. Usually it’s more like “filtered light.” The difference that makes at 3PM when the kids are done schooling and it’s 113 is astronomical.

[ahosey01]

21 minutes ago, Dimovi said:

Are the plants established? Once established the roots should be so deep that moisture sensor won't indicate much. Deep, less frequent watering stimulates root growth deep into the ground. Here in Austin I water once or twice per week and the highs in July have been well into the 100s, but humidity is higher at around 30% during the day. I probably would not water so often if I did not have free water. The biggest difference is probably the soil. Clay and loam can retain moisture for much longer than sandy soil.

My soil is silt.  It rolls like clay in your hand, but it drains like sand.  A foot-deep hole saturated and then re-filled will drain in about an hour in the most compacted part of the property.

And no - most are not established except for the old eastern broadleaf trees.  The house was recently built on this property so all my stuff has been planted since May.

[zero]

1 hour ago, ahosey01 said:

a lot of desert native species - ironwood, Palo Verde, acacia - they don’t really strictly provide shade.

This is so true.  I planted a couple of Palo Verdes near my palms because I like them and they don't shade out my Bismarckia or Copernicias that love full sun.  My deciduous and other evergreen shade trees are providing shade on the west and north side of my house.  We're not getting temps quite so high as you but still in the low 100's each day.  107° over the weekend and cooled down to 103° yesterday and again today.

[AZJakeB]

19 hours ago, Dimovi said:

You should not have to water every day unless maybe the soil is sandy and the plants are not established. You can mulch to slow down evaporation and to keep the soil cool and insulated from the sun. 

Dactylifera has insanely long roots as most desert/Mediterranean palms.  The roebelenii is probably the most needy.

Dig into the soil and see how far down it is dry.

Arizona full sun is way different that Texas full sun.  It might take watering every day to keep from drying out.  Even yuccas are yellowing out and dying here.  

[Silas_Sancona]

17 minutes ago, AZJakeB said:

Arizona full sun is way different that Texas full sun.  It might take watering every day to keep from drying out.  Even yuccas are yellowing out and dying here.  

Agree completely.. especially valid w/ anything in containers. 
 

[amh]

On 8/18/2020 at 9:09 PM, AZJakeB said:

Arizona full sun is way different that Texas full sun.  It might take watering every day to keep from drying out.  Even yuccas are yellowing out and dying here.  

Not really, we just have more humidity. Our yuccas and cactus die from drought and heat all the time.

[ahosey01]

2 hours ago, amh said:

Not really, we just have more humidity. Our yuccas and cactus die from drought and heat all the time.

I don’t think this fully captures it.  We can go half a year without not just rain but even clouds, humidity is often in the mid-single-digits and we’ve spent almost 2 months straight above 110. Here was a week in Parker recently:

That type of sun is a whole other thing.  Often, it’s 110+ by 11:00AM and doesn’t get below 110 until well after the sun goes down.

I remember the first time I took my wife to south Florida, we went in August.  She loved the weather because she pointed out that when you’re walking around in the heat, it’s only like 95 and you get brief breaks from the sun because of the clouds.

Edited September 7, 2020 by ahosey01

[amh]

I know it's an apples to oranges comparison, but Texas west of I35 is very hot and dry. My area just finished a 4 month stretch of no rain and temperatures above 100; which is not uncommon.