I was reading an old ag publication from around 1900 last night that mentioned that they found a dilute spray of white paint on the whole tree delayed bloom by up to two weeks.
Given the wacky weather we are having I think many of us may need to start thinking about doing this. My plan this weekend is to put down Surround plus a massive amount of sticker on all my early flowering plants (apricots and kiwis for sure and maybe Jap. Plums). I wished I had done it earlier as it could have kept the trees from getting as far along.
Sounds like a good idea Scott, I am going to be doing my oil and copper spray on my peach trees today and wondered if you had any thoughts on if it would be better to add the white paint before or after the oil spray or does it matter which one is first? Thanks, Chris.
Interesting Scott. Sounds like a worthwhile test. My assumption was that it reflected more light and prevented the buds from warming too much in the sun but the link you provided states that the bud temperatures were not altered. Did the old publication state why they believed it worked?
In a side note, this year was the first time I ordered trees from Bay Laurel, and apparently the warranty is voided if you don’t paint your tree white. I didn’t know it was that common of a thing to do.
I would have done it anyway due to sunburn in this Georgia sun, but it’s good knowing it has another side effect.
Hi Chris, I know nothing about adding latex paint to a spray. One of the reasons I was going to use Surround instead is it is a known quantity.
Brad, my guess is the temperatures of the wood was altered and that made the difference - that study apparently measured bud temps only. Your pistachio reference seems to support that, they got more chill which translates to colder temps with the Surround.
Bay Laurel is in California and probably sells a large percentage of their trees in California. Painting trees white is very common in the California central valley where summer sunburn can cause serious damage to trees.
That was my guess as well (that temperatures were affected at some level). I think it’s something that’s worth exploring for those of us in the south and east. A boost in chilling hours would be welcome here (particularly in some years) and these spring temp swings can be rough. We have been warm the last few weeks (high of 77 today) but are supposed to dip to 34 tomorrow night. I’m hoping we’re done with our hard freezes.
Michele Warmund at MU is still doing research on delay of bloom with peach trees. Originally she did some work with diluted latex paint, but now she is experimenting with ethephon. I printed off a small paper years ago, when she did the research on the latex paint, but can’t find it on the internet any more. If anyone wants any more details, I can probably find the paper in my files and relay those.
Scott,
I’d be interested to know how well the Surround works. I’m a tad skeptical though because I’m thinking it may have to be kept on all winter to work (so that it slows chill accumulation). If that’s the case, wouldn’t it require quite a few sprays to keep it on?
I’ve never worked with Surround, so I’ve no idea how well it would stay on in the winter.
I wanted to try the diluted paint thing, but it would be too expensive for me to apply.
Thanks Scott, I did not word my question well, I wanted to get your opinion on if it would be better to spray the oil, let it dry, then spray on the paint or if it may be better for killing overwintering eggs, etc. to spray on the paint, let it dry and then spray on the oil.
I didn’t word my answer too well either - I don’t know anything about how paint behaves as a spray. Personally I would probably just throw it all in the tank. I expect that would all work OK but I’m not sure.
@Olpea, for me the chill doesn’t matter as much – trees with low chill still stay dormant as long as it is really cold out in spite of making their full chill many months earlier. I think if I put it on before any bud swelling I would see an improvement. Using paint is probably a better idea, but I need to have Surround on later anyway and nailing a first coat on with a massive sticker amount may not be a bad thing.
I believe lots of folks do this practice (painting the trunks) in the north to prevent sun scald. Never heard of a mist type paint spray to delay bloom. Interesting…
Hmmm, one of the claims with Surround is that it does not reduce the light which hits the leaves when used during the summer. If that claim is accurate, then I fail to show it would be of much good reducing tissue temps on stems and buds. Unless of course it has different reflection at different wavelengths of light.
In any case, I would think that 50:50 latex paint would be a safer bet.
I stopped at wally world and picked up a quart of white flat indoor paint. It’s Glidden brand and was on clearance for $5. Came home and mixed it 50/50 with water. Proceeded to paint the trunks of all my trees. I thought about putting a real watery version of it in a sprayer and painting one limb on my Methley to see if it slows down the bloom versus the unsprayed tree. But at this point it’s probably too late as the Methley buds are about to pop.
On a side note I got my first blooms today. Flavor Delight which I grafted last year are wide open.
Steve, Surround obviously reduces the light, white is white because all the colors are being reflected and not absorbed – in other words, your eyes are directly picking up the fact that less light is absorbed. I think what they mean by that is the plant is not getting photosynthesis reduced, because for some of the hottest parts of the day the plant is in fact getting too much light and heating up too much. I expect paint and Surround are no different as they look the same to my eye-detectors.
@mamuang, you can probably mix whatever you want with it. The sticker is fine before the bugs hit.
@speedster1, I think it helps more to spray or paint the whole tree. The more surface you have painted the colder the sap is the longer it will stay dormant.
PS here is the original excerpt. Looks like it said 7-10 days not 14. This is from “The Plum in Georgia” from 1904. This booklet has all sorts of other interesting information in it including a lot on southern native plum varieties from a long time ago. Here is a link to an electronic version of the booklet
Probably right Scott. Without knowing the micro details of how surround sits on a branch it’s hard to say. What looks like an even white coating to our eyes could have quite a few tiny gaps, which would allow some heat gain; although it should be better than uncoated.
If you have access to a non-contact thermometer, a comparison of surround vs paint o a sunny day would likely tell.
I wonder if they only used homemade whitewash for this method? I’d be willing to try it on a tree or two. Probably don’t have enough time this year.
For us, normally it’d probably stay on pretty good since our winter precip usually comes in the way of snow. The wind would probably blow it off to some extent. This year, HA! We have had 2" of rain since I reset my weather station on Jan 1, and we had a bunch of rain on Christmas. That said, enough applications of Surround to peaches will permanently stain the truck and scaffolds white. I have only done one year of spraying and have noticed this on my peach. It is less staining on my hybrid plums, and intermediate on apple. I also always make sure to spray the trunk good on my peach under the idea that peach borers might be repelled like curcs by Surround. So far so good.
The short answer is: for the tree is should be fine.
I have a more nuanced answer in mind, but it is hypothetical. My day job is teaching environmental engineering students how metals like copper interact with soil minerals like kaolin clay. There is some concern that Surround could lower the effectiveness of the copper spray as a fungicide, but it is only a hypothesis for which I have no data.
