There are some varieties that seem more sensitive to full sun than others. Most of my plumerias are in full sun on the blacktop (Singapore and DSP included). But a few such as Divine and an unknown Premium White from Jungle Jacks seem to do better if they get shaded for half of the day. It could be also they aren't getting enough water and thus the leaves desiccate easily under full exposure.

Walley,

Most younger plants will prefer some sort of afternoon part shade. Each plant may be different in this respect so you are going to have to move them around a bit to find the best amount of light.

Usually necrotic leaf tips and margins are associated with a compromised root system, with root function being inhibited to the point the plant can't move water efficiently enough to keep up with water demands. The symptoms usually manifest themselves in the most distal plant parts - the parts water has to move farthest to get to, which are leaf tips and leaf margins.

High root temperatures CAN be a factor, and should be a consideration, but also very high on the suspect list are over-watering and a high level of salts in the soil from fertilizer solutions and tap water.

Over-watering and a less than ideal soil choice often go hand in hand to diminish the oxygen supply in the root zone. Uptake of water and nutrients isn't a passive or energy-free process, it's energy driven and adequate aeration is a key ingredient, without which the root system cannot carry on transpiration, which is the energy-driven process on which the uptake of water/nutrients depends.

If you're not watering correctly, to the point where at least 10-20% of the total volume of water applied exits the drain hole. salts can accumulate in the soil (solution). The greater the level of salts in the soil, the more difficult it is for the plant to take up water. Unfortunately, a high level of solubles in the soil ALSO usually accompanies a water-retentive soil because our natural tendency is to water in smaller sips to avoid the poor effect extended soil saturation has on root function and/or to avoid root rot. When we water in sips, all the salts from out tap water and fertilizer solution remain in the soil, and can work in concert with saturated soils and low O2 levels to further compromise root function.

I'd suggest you shade your pots or double pot (maybe Laura will share some of her pictures with you), and that you try to make sure you have your plants in a soil that allows you to water correctly, which would be a soil that allows you to thoroughly flush your soil at will, without the fear of the soil remaining soggy so long it compromises root function or causes root rot.

Finally, being badly root bound can also inhibit water movement throughout the plant, so you might want to give that thought some consideration next spring at repot time.

Al

Wally I have found that if the plant doesn't have a strong root system, it will need to be in partial shade, in the hot months here in Texas. Rockport is cooler than San Antonio, and I have all my new plants (June, July, August)t getting dapple sun. My plants that I got in the early spring and last fall are in full sun. I get my plants in April from Florida Colors, she grafts the cuttings on 2 yr root stocks. Those plants are now in full sun and thriving. Barbra

I agree with honey.
Mine get full sun until 2pm, then shade in our 100 degree days.
Lonnie

I also put my little ones in partial shade, especially when they are just recently repotted or newly rooted cuttings. The more mature trees that are in full sun all day are the mature trees that i know will tolerate the high temps. When the temps do get into the triple digits here in VA, i do double pot my trees . The ones that are exposed all day to the sun. They probably receive full sun from 10 am until sunset.

Certain varieties like others have mentioned are more sensitive to the full sun. You just have to get a feel what the trees like and how much they can tolerate.

I know the temps can be brutal down in your area.

Always acclimate your trees to the full sun... if they still don't like being in the full sun that long, i would put them so they would receive less sun and receive some afternoon relief..

We have temps like that for about a month, then they average around to the mid 80's to low 90's during the rest of the summer.

Here are a few pics of the way i double my pots to protect the containers and the roots from to much heat during those triple digit days.. I worry that the roots will get to hot and just fry in the heat. This would be a disaster for all of my treees. So i just help them and protect them as much as possible.

Good Luck!!

I take the container and place it in another and place mulch around between the two containers. This protects the roots and still lets them receive the full sun.

They also receive water when needed. Everyone had different soil mixes. When they dry out, i water.. I also dont worry about over watering when they are in a fast draining mix.

Take care,

Laura

wow thanks for the great info guys! I am using miracle grow potting mix with perlite i water just 1 time a week. I did repot them into larger containers because they would tip over due to high wind so Im guessing stress from that might have contributed or just the fact they are just new plants getting settled in. I will put them in partial shade just in case the heat is too much for them and try to push them out to more full sun over time.

Given the soil you're using and the description of where the leaf damage is occurring, it's far more likely it's a root issue due to the combination of soil/over-watering - especially given the fact that your watering intervals are a week or more. Photo-oxidation (aka sunburn) usually shows up as large areas on leaves, usually not favoring margins or tips, that first appear silverish or gray, then turn brown or black - unlike what you describe. I would be seriously considering a soil like Laura uses, one with better aeration and drainage, a soil that doesn't support nearly as much perched water as the one you're using. There's little question that change would help you get much more out of your plants in terms of both growth and vitality, and would allow you to avoid the spoiled foliage, as well. Your choice of soil is probably the choice that has more impact on your ability to get the most potential from your plants than any other. Let me know if you want more information; if so, I'll provide you with a link or two that should help you better understand the role of soils and how to get them to work for you instead of against you.

Al

I use mg, your mix is fine for Texas and is what most of the growers in this area use, or just potting soil if you don`t want to mess w/perlite. I mixed 1:1 to root cuttings in an experiment. Some of the soilless mixes just get way too hot to use in full sun here in Texas. I also try and avoid those black pots finding they also get way too hot in full sun. I mulch around all the plant both in the ground and in pots. I`m in Galveston where the heat index at 0330 is around 100. Full sun is FULL semi-tropical sun. We are in the cataract belt if that tells you anything.

I have sunburned plumeria after moving them from where they didn`t get enough sun to full sun. So now I move them slowly to increasing sun, the seedlings, smaller plants are shaded by the larger ones. I have left a big one in full sun and it recovered just fine eventually dropping all the sunburned leaves as they were replaced by healthy ones. Cuttings are on the front porch in full sun from early am to around 1500 in the afternoon. Everything else get full sun from daybreak to dusk. I water every 1-4 days depending on where they are located and the size of the pot they are in. IE: 1 gallon pots on backdeck, full sun all day, wind, water daily, right next to it is a plant in about a 35 gallon Mexican pot, it gets watered about every 7 days. Plants in the ground, which is sand we do live on a barrier island, every 3-5 days.

Tally Ho!

I can promise you that TX sun will burn your plumeria!!! When I got mine, the directions said "Full sun, the hotter the better". WRONG! That may be right for colder climates but they can not stand the Alabama or Texas "Death Valley" days of 105 degrees for a month or two. I finally wised up and placed mine on the porch so they get the early morning sun until around 11 AM and the porch overhang shades them from the scaulding heat for the rest of the day. They are growing profusely now. Hawkeye

Wally I use K's plumeria mix on my potted plumeria, I cannot water but once a week. He shared this with me last October, when I bought my first plants. In the spring I tried the gritty mix. It is great for rooting cuttings, but requires regular waterings for potted plants in our 100 degree weeks. My plumeria are 177 miles from where I live and are on there on. I go down every weekend and hand water. Since I have 100% white sugar sand for soil, I have to use 100% MG potting soil, when I plant anything into the ground. I would not recommend this for San Antonio Soil, unless you live by Floresville. Barbra

Wally, just try it, most of us did. That is the best advise I can give you. Today I went to get my Foliage pro, and pro tekt. He gave me a sample of something he thinks will do better on my plants. He told me to spray half my plants with foliage pro and the other half with the sample. I will let you know what happens. He told me something interesting about pro tekt. How important it is when rooting cuttings, to spray on the stem ,it will keep the stem from getting soft, and help develope roots. Pro Tekt was $39 for a gallon. I bought it to help my plants that are in full sun. This store is in San Antonio, off I-35 just before you get to Splashtown. Barbra

well I will push them back out into the sun I have not watered. I stuck my finger in the soil and it seems like there is still moisture in the soil. I will see if they start to recover. So far does not look any worse. I am investing in a moisture meter to help me know when it is time to re-water. The soil does get pretty warm during peak of the heat should i be concerned?

Yes, you need to be concerned about soil temps. There are a number of ways to help keep roots cool. Burying the pots for the summer where possible, using the pot-in-pot technique (see Laura's pictures above), shading the pots, watering at midday when root temps are highest, using light-colored pots or painting pots white or pastel ..... are all helpful.

Water gauges aren't helpful in determining moisture levels of soil. They measure EC (electrical conductivity) of the soil solution, which actually makes them much better at gauging fertility than moisture levels. If you put a water meter probe in distilled water, it will read 'dry'. Add a little table salt or fertilizer to the same water and it will read 'wet'. A wooden dowel or skewer is better as a 'tell' for determining moisture levels. Stick it deep in the soil - if it comes out cool/dark/wet, withhold water unless you are pretty sure the soil will be too dry before your next opportunity to water.

Barbara - I'm a proponent of Pro-TeKt, but there is no physiological reason that applying Pro-TeKt to cuttings would be a good idea, and there is nothing in it that would promote rooting. I sure wish the person who gave you that advice was available to explain his reasoning. I'd bet a week's pay he can't, but it's your call.

Al

Heck it sounded good to me. It has something to do with the silicon solution. I have the perfect plant to try it out on. It was a newly rooted cutting, that fell out of the pot in back of the truck. It was back there for over 4 hours, and it was over 100 degrees. It was healthy, now it is limp, and has lost all its leaves, 2 weeks now and no change. If this doesn't work I know I will loose the plant. I should know something by Sunday, when I have to drive back. I am going down Thrusday. Maybe I am just a fool, but i really did believe this guy. I went there to buy it, so he was not trying to sell it to me. Barbra

Hello Everyone,

Great information!!

I just realized that the actual sunburn from some of my trees was caused by stressed roots...

The light still goes on AL!! Thanks for the explanation.
I just enjoy learning things and understanding the reason why!!! I get excited when i understand... (it may take awhike..) But when i do get it.. i can't wait to try...

I do try and protect the roots when the temps get so hot here in VA. But with all of the containers that i have on my deck it would be impossible to move from the heat of the summer, that is why i startd with the pot in pot.

Just like some sink their pots or "Plunge" It is simply giving the trees the protection the they would normally have if they were planted in the ground like they were supposed to be.

Since most of us cannot plant our trees in the ground and leave them over the winter, we have to keep them in containers. I will say that i do move my little ones that are not established yet and do not have a good root system around to protect them until they show me that the roots have taken a hold and have a good amount of healthy roots before i transition them into more sunlight.

It really does make sense to me. I have started using the Gritty Mix on lots of my trees and i will say that i have been very happy with the overall health of my trees. SOme have not been rootpruned and i will wait until spring to do that. But i did get many of my trees done this spring and summer. They all are doing great in this mix..

I do like the black pots. They really help my trees get going and warm my trees in the containers early in the spring and then in the fall. Now... in the middle of the summer when we do have high temps... I will protect.

Once, i even went to the store and bought white shelf paper and cut them to cover my pots from the high heat period . It wasnt pretty...LOL, but it worked. I didnt have to move those huge trees and i didnt have any sunburn on my treees.

Now, When i did have trees against the brick area.. i noticed problems, so i moved them. Way to much heat..

After I did one season with the "White Contact paper" I decided to buy the plastic Terra Cotta colored pots. I have them on the side of the house to reuse when needed. When i pull them from the other plastic pots.. i have to cut the roots that have grown so much from the holes on the bottom of the contsiners. That showed me that they really like the protection. More root growth in the pot in pot verses the stndard pots ( leaving them as is..)

It was a simple solution to take care of the problems associated with high temps around the roots. My trees have been very healthy this year and i attribute this to the Fertilizing plan, watering plan, and my selection of Mix.

Everyone has reasons for the soil choice they use. I agree with AL and I uderstand Barbra that she has reasons why she can only water once a week. Everyone has their reasons and priorities.. We all work and some have little ones.. So it does take time.

I want the best for my trees ... so I will make the effort to make the mix that works best for me and gives my trees good aeration and keeps the pertched water to a minimal level. Its what i want and love to do!!

Most of you all know i work and im away for days at a time. Some of my trips are 4 days.. ARGGG! I dont like those trips, but.. I can water before i leave and they are fine when i get home , i water them again. You can adjust the makeup of what mixes you make to help with water retention for people like me.

Just wanted to say that there is alot of good informtion here and you may have to reread this several times.. : )

It is alot of information to take in, but it is sound information that i have used and i can say tht it works well for all of my trees. Especially my DR's and all of my Citrus and Cactus and Succulents. I like to use it while rooting too.

OK.. Ill just say that the light went on again in my head when i think about sunburned leaves.. Now i understsnd that it is a reaction to the root system letting me know that something is wrong... same as when its a water rentention issue.. or root rot. It all shows us the reaction in the leaves first to give us an idea that something is wrong.

Mother nature is so clever... : )

Thanks everyone for their input.. It is good to have all of this informtion available to us so we can learn.

Thanks again AL.. I do know that you have taken alot of your time to post this informtion, so i want to thank you..

You have always been helpful here and at the other forums.

Thank you for taking the time to offer advise.

i always learn something everytime i read these post...

Barbra. you are no fool...See what happens and then you will find the answer.. If you look at the bottle of proTeKt, it explains how it works. Im glad you have the PT to use. You will like it. Many others use it and have for a long time. I just started using it this spring and i use it faithfully. Love it too!

Take care everyone!!

Laura

I have a plumeria that has developed little spots on the edges of the leaves. What is that all about? I’m in Tucson and it’s been very hot this week. BTW - it’s a new plant - very small.