A shade cloth on a temporary frame would accomplish the same thing.

Thanks John, but will this type of tree ever adapt? My others do not wilt like this.

All of my trees wilt like that in the extreme heat. It will bounce back or grow new leaves more suitable and adapted to hot weather.

Evan

The newest most tender growth will likely continue to wilt in extreme sun; but as the growth hardens off, it will be fine. The shade cloth will only be necessary temporarily, when you have tender new growth and the sun is especially hot. The reason your others do not wilt the same is a matter of phenology; the wilter has softer, more tender new growth. With a little shade and adequate water, you will be surprised how quickly they adapt.

The roots are not keeping up with the extreme hot sun so they wilt...When mine do that, I either cover them until the roots warm up or put them in shade..It's normal for mine..Especially when my temps drop to the low 50's by night like this morning and then rise to 85 within hours in the hot sun. All the new growth wilts!

Sometime too I soak them in the a.m raising the root zone temps with warm water before the sun hits them and it works wonders)

Thanks guys. I'm happy to hear that this too should pass. Mike, I'm going to try a thorough drenching early morning to see how that works. It was roasting here today...90...in the sun it must have felt like close to 100. The others don't seem to suffer as greatly though.

Good idea..Some of my tree are not affected at all depending on the root size, pot size, where they are located and the micro climate..

I know that the roots will not take up moisture quick enough when cool to keep up with the hot sun on the leaves..That's why I either find a way to warm up the roots before the hot sun bakes them, or stick them in a less sunnier area until the air temps rise enough to heat the roots up so they will function)

Laura, did you measure the root temp? If ambient was 90 F, perhaps root temp was 100 F. Citrus roots start to show damage at about 104 F so it's possible that they were not functioning normally due to high temp.

I should have Vladimir, but did not. We did create a table and have one data point. We are measuring three trees.

Your tree looks really nice. I bet it will bounce right back, some of my citrus did the same thing over this last HOT weekend.

Join me in the garden! ➜ https://goo.gl/GHO5MN

Laura, the new growth on my citrus shows signs of wilting also. We had a number of days where the temperature soared. I had my citrus on a table that got direct morning and early afternoon sun. In the mid afternoon, when the sun gets brighter and hotter, they get filtered light and shade from nearby fruit trees. I made the mistake of moving them to a spot where they get a day of full sun thinking it would be better for the plants and new growth. That is when I noticed the wilting on fresh growth. They were watered well in the morning so I had no clue why that happened. After reading this post I have moved my table and citrus back to their original spot. Thank you everyone for the helpful tips.

Thanks guys! I'm happy to hear it should adapt. I guess I was surprised because my Oro blanco has growth like that and it does not wilt...although perhaps the new branches are a tad bit older. I like the idea of shading the pots and will try it next sunny day. As I type this, there is a huge downpour with lots of lightening. I've always liked storms, but now I like them even more because I think of all the nitrogen my plants get!! Ginny, I'm happy to hear the discussion has helped you also and that I'm not alone with my wilting issues ;-)

I found this map of annual nitrogen deposition in USA:

Now, if you say the average is around 5kg/ha, that is 5000gm per 10000square meters or 0.5gms per square meter.

I found this table of citrus tree annual nitrogen needs:

So, a young tree covering about a square meter needs 150gm of N each year, and rain could provide half a gram. If the diagrams and my maths are right, that won't make any significant contribution at all.

Citrange2, that is fascinating! However, I think there was a problem with your conversion from kg to mg - kg. A kg = 1000g, therefore 1,000,000 mg.. Assuming all of the same conditions, then that would equal 500mg/sq m. Unless I've made a mistake with the ha unit.

Unfortunately, I left out the caption to the table of N requirements

"Recommended Fertilizer Rates of N, P and K for Citrus Trees (G/Tree/Year)"

So I was working in gm, rather than mg. But your answer of 500mg/sq m is exactly the same as my 0.5gm/sq. m!

The original articles are interesting and can be found at:

Nitrogen in the Nation's Rain and

Fertiliser Management for Citrus Orchards

Oh....that explains a lot! Thank you for the clarification. It really is incredibly interesting!

So she is wilting again today. This time I checked the root temperature....only 84. I moved her to shade. Hopefully she will adapt soon. That tree seems to have the most trouble with the heat.

How long ago did you pot it? Could it be that the roots have not had enough time to develop and so cannot absorb water fast enough to keep up with transpiration?

Maybe two months?? She has grown tons since.

Totally normal until the roots fully and I mean fully colonize the pot. That takes more than a few months though.

Thanks Pip, that's good to know. I will just keep transferring her to shade when she needs it.

Did you try shading the sunny side of the container?

Josh

Painting the pot white helps too

No I did not try that bc I tested the temp in two places and the hottest I got was 84. I figured the roots were not overheated. Ivan try that the next time.

Glad I found this thread as my Meyer recently put out several new 2' long branches and the leaves on these shoots seemed to wilt mid day just yesterday. First time to see this on my plants. I drenched it and it seemed to respond well. Just now getting warm 25-29 c here mid days, so maybe the pots will need some shade once we are having more sustained hot weather.

Hi Laura, is your ST doing better?

Yes Roland, thanks for asking! It has recovered from the sunburn and is putting on growth...but we are back to wilting in the heat!! Ugh...I had to move her back into dappled shade. For that matter, Suzu, I have the same issue with my big Meyer. The new growth is wilting...I did not move him though....he needs to toughen up! He is just too large to move around easily. Even my Oro Blanco, that is tough as nails in the heat wilted ever so slightly (the new growth). It has just been unbearably hot and sunny here lately. I am sure I will be longing for those days come winter, but for now, between the heat and mosquitos, the summer is driving me crazy!

same with my ponderosa lemon mine is in dappled shade but still some of the new growth was wilting but it recovers in the eve so I let it be.

Two of my seedling tree transplants are having a hard time with this heat and also a new rhodendron I planted in the ground this spring is suffering severe wilting this week. I hope they survive it. This really has been a hard, hot summer for them. Laura, I have not forgotten about the Moro seedling I promised you. It just seems better to wait to ship it yet as it has just been so hot.

Cory

Cory, have you been in the midst of a drought like me? It's horrible///They say the worst since record keeping began..

Cory, no rush or worries!!! Mike, we also have not had rain, but are technically not in a drought (yet). I think there's rain in the forecast for Thurs.. Another scorcher today...high of 88...ugh! Kids start school today, so I'm off...at least I'm back on my schedule of exercising before they wake up. Still hot, but energized. Stay cool guys!