I might as well start off first with one of the hardest things I've dealt with. Getting a successful crop of peaches in the Southeast is tough. Georgia is called the Peach State (many in South Carolina sneer at that; they produce more peaches there). However, peaches are not a plant-and-harvest crop here, or at least, I have not found them to be. I've had to deal with two things that work against getting a successful harvest: brown rot and plum curculio.
Brown rot is a plant disease that can infect peaches at or immediately after bloom, or later in the growing season. As peaches ripen toward the end--when they become somewhat soft and smell peachy--they are particularly susceptible to brown rot infestation.
These are peaches I pulled off in a prior year because of brown rot. Most years I lose about half my crop to it. To mitigate brown rot damage, I have implemented several steps:
I mulch under my trees with cypress chips, and rake them up each winter in the dormant season and replace them. This also rakes up fallen peaches from the prior season. Brown rot can overwinter in twig and branch cankers, mummified peaches, and fallen peaches.
I spray fungicides. I use a lot of products. Daconil can be sprayed in the dormant season and up through full bloom--it's not considered organic. Lime sulfur and copper sprays can be used, as well, as can captan (these latter ones are considered to be organic). It's important to engage in dormant season spraying, at bud swell, first pink, full bloom, and post-bloom--until harvest. Commercial orchards in this part of the country do 40 sprayings a year for plant diseases and insect pests. After petal fall, I usually use captan exclusively. It's a wettable powder. It's not a panacea--the sad spectacle above happened when I was spraying captan frequently--but it does produce some control of the disease pressure.
I also harvest my peaches when not quite fully ripe and let them ripen indoors. That seems to reduce the losses to brown rot dramatically.
This was my dining room table a couple of years ago with picked peaches finishing up. Once brought indoors, I do occasionally lose peaches to brown rot, but it's much less of a problem.
As the peaches are starting to ripen, it's very important to scan the trees
daily and pull off peaches starting to get brown rot. A peach can be completely consumed in just a couple of days and while the brown rot is destroying that one peach, it will be throwing off thousands of spores that can infect adjacent peaches. Twigs can also become infected and die; it took me a couple of years to figure this out, but I noticed that the leaves next to brown-rotted peaches would turn yellow. These doomed twigs need to be pruned out or they'll serve as reservoirs for future infection.
Controlling insect damage is something that I have belatedly realized is important in controlling brown rot, too. An insect bite on a peach that breaks the skin seems to open it up to injury. I don't have a picture of this for you, but I frequently find that if brown rot is just starting on a peach, at the center of the lesion will be a hole bitten in the peach by some insect--it's not just plum curculios that victimize peaches.
Elberta is a variety that is somewhat brown rot resistant (table of varieties and their resistance can be found here:
Varieties List-University of West Virginia ). Another thing that I think would help is planting early varieties (this would be good for both insect damage and brown rot). My two varieties at the house here are Belle of Georgia and some unknown early cling peach (it was supposed to be Elberta, but it ripens in mid-June and almost every time the pit has to be cut out; freestone it most definitely is not). I love Belle of Georgia, but it's highly susceptible to brown rot--maybe that's not so bad for California, but it's not good here. I get a crop out of my BG tree almost every year, but I lose a lot of it to disease. The problems with early varieties are that 1) they're clingstone in most cases and 2) they're less available.
Next up: plum curculio. This nasty little bug attacks stone fruits most of all (as the name suggests), but it also goes after apples and pears. It's a small snout-nosed beetle, and the female carves c-shaped flaps in the skin of developing peaches, then lays eggs. The larvae burrow down to the pit and feed. Curclio can be defeated a couple of ways: barriers and insecticides.
Commercial orchards generally spray imidan, which is a pesticide not available in the small-scale retail market. Malathion or Sevin work, as well--they just have to be applied frequently at the right times.
Most people I talk to don't want to spray insecticides. That leaves barriers, and the only viable one I know of is Surround--a kaolin clay powder that can be mixed with water, then sprayed on the trees. I use 1 cup per gallon (more clogs my sprayer), and at least three coats need to be put on to have a deterrent effect. The goal is to make it so the curculio don't recognize a host tree when they land on it. Reapplication is necessary after a heavy rain.
This sounds like a major pain, and it is--but a couple of coats can be applied in one day, then another one the next day. I have gotten pretty good control with Surround--I generally have attack rates of about 5-20% with Surround vs. as high as 80% without it. One problem with Surround: I sometimes spray just the developing fruit, and other times spray the foliage, too. Plants can allegedly photosynthesize even with the clay on their leaves. Belle of Georgia does
not like Surround. Whenever I have sprayed the foliage, I've soon gotten a lot of leaves turning yellow and dropping off. So with BG I target just the fruit.
When to spray: Basically, you have to have control in place before the wretches start laying eggs. You can use degree days:
NC State Degree Day Model
It sounds complex but is not bad. Take the second day when the temperature is over 70 and use that as your start date, then calculate degree days (DD) using a 50-degree basis. The curculio are on the move from 50 to 400 DD and are laying between 100 and 700 DD; a second generation goes to work after 1100 DD. Last year in my area, my start date was 3/31 (which was somewhat late) and I hit 728 DD on 5/26, at which point I suspended further Surround spraying. You can calculate DD manually, or use calculators available online:
Pioneer GDU Calculator
Bizee Degree Days Calculator
The Pioneer calculator doesn't have a basis temp, but 50 is usually used for corn, too, so it should work ok. The Bizee calculator can do heating or cooling with a user-set basis temp and outputs a CSV file. Many states have weather station networks that have DD calculators, also. In Georgia:
Georgia Automated Environmental Monitoring Network
What this all shows is that you need to start spraying very soon after petal fall. My peaches are usually in bloom anytime between the first and third weeks of March. Soon thereafter they need a barrier to deter curculio.
Surround can be bought online--a few places sell small bags; Seven Springs Farm has a decent price for 25 lb. I got a single bag a few years ago and still have half of it.
Seven Springs Farm-Surround
Now, you might be able to grow peaches with no spraying whatsoever. In California or the Desert Southwest, this might even be the norm. There are no curculio out there, but they do have coddling moth to contend with in some places (which have a similar impact). The low humidity mitigates against diseases. It can work even in the Southeast--I have a friend here in the Atlanta area with a tree in her front yard who doesn't do any spraying, and she still gets peaches. With both of these pests, however, prevention is better than treatment. I got some peaches my first couple of years with no spraying, too, then the curculio found me and brown rot came soon after. Once either gets established in your orchard--even if it's only two trees--you can probably forget about getting a viable harvest with no spraying in future years. It's probably best to start a good control program that will prevent outbreaks of either problem.
Another plant disease that hits peaches is bacterial spot; My BG got that one year but the peaches were still edible. It's mostly cosmetic, but does make the skin of the peaches somewhat tough.
University Extension pages have a wealth of information about successful peach growing. For example:
University of West Virginia
Peaches
can be grown successfully--it's just a lot of work. My first two trees--mentioned above--are on dwarf rootstock and I have gotten as much as 130 lb. off of the two combined. 70-100 lb. has happened several times. This year: zero... a late frost after bloom wiped out the crop :-( That has only happened a few times in the 15 years I've been growing them.
The background photo on this blog is from my BG tree last year. It can be done and it's satisfying to bring in a successful crop. Then you just have to figure out what to do with all the peaches. That will be the subject of future posts.
I've now gotten another couple of trees that are standards; they're late-ripening freestones (Bounty and Contender). They haven't started producing yet. I'm thinking I should hunt up some early clingstones...
Despite the name, it usually ripens in July. Still, that makes it a summer apple. It's an old variety. The only way you'll get one these days is to go to a nursery that specializes in old apples, like Big Horse Creek Farm. Striped June is somewhat tart/sweet. Partly that might be due to harvesting a bit too soon, but the apples were looking good Sunday, with a few already on the ground. So I picked it clean. I'm not out there every day--this isn't in my back yard; it's a ways away--so there wasn't any viable alternative. As you can see, the apples aren't exactly ready for retail. Most have some degree of insect damage (though I've verified that mostly it's just a few small divots, not really affecting anything else), and many of them have sooty blotch and/or flyspeck. Both of those are benign plant diseases that don't affect anything. They can be rubbed off the skin with a wet paper towel and some diligence if you must, but as far as I know, they're harmless. They certainly don't affect fruit quality, except for visual appeal. I also see russeting on a lot of them, not all, and that doesn't bother me, either.
Here's an interesting thing about Striped June/Margaret: According to a Jurassic PDF from Auburn University I stumbled across one day, it's resistant to cedar-apple rust. Look on page eight of the PDF (which, surprisingly, is searchable). Early Red Margaret, which I assume is the same apple that I have, was found to be free of cedar apple rust way back in 1908. I have cedars near where the apple tree is growing. The woods have cedars here and there, and there was a huge one about 50 feet away from the tree, which I cut down with a friend. There's still one within 100 yards. And there are others. I saw galls on the closest one. The disease can travel some distance (it's transmitted back and forth between the two species, and others--like serviceberry--get involved, too). I have another apple out there that has issues with cedar-apple rust, getting it every year (so far). I planted a modern disease-resistant variety, GoldRush, another of the PRI apples I have, along with a few others. GoldRush, alas, while resistant to some of the worst diseases plaguing apples, is susceptible to cedar-apple rust. The new apple trees are too young to set any fruit yet, so we'll see what happens. GoldRush did have a small one this year but it fell off (as do a lot of the leaves about now). At any rate, my Striped June has always been rust-free (at least for the few growing seasons I have had it).
