I have been promising for some time to type up a draft of the “low impact” spray schedule I use. Here it is, drafty but it will be refined. My rough guide for low impact is no wide-spectrum poisons. Spinosad is about as broad a poison that I use. I don’t personally draw the line at organic vs not, but this schedule is mostly organic and I will suggest some substitutions if you want to be 100% organic. If you want to have a philosophical debate over what to (not) spray, please put it on a different thread.
My goal is not perfect fruit, that requires too many sprays and/or poisons. Something like 80% bug-free at harvest and with only minor disease issues on all fruits is the goal. Sooty blotch is a minor disease, some varieties will get a lot of that.
This is really for me only
Everyone has a different climate with different pest pressures. I am in a fairly hot and humid area, and have many spots with too little sun. This is what I evolved for my climate. You need to pay close attention to how the trees are doing and adjust based on your circumstances. Hopefully it provides a good start at least.
The importance of monitoring
Until you are intimately familiar with the seasonal flow of diseases and bugs in your climate you need to frequently monitor how the trees are doing. The first step to that is to make sure you have a dead-on diagnosis of every major bug and disease issue you spot. If you can’t tell curculio from moth damage you will not know how your schedule needs to be adjusted if you are getting too much damage. For curculio, regular monitoring will allow you to spot the fresh crescents right when they appear, and clue you in to the need for another coat of Surround pronto. Moths can be monitored with pheromone traps - you can’t spot egg laying and by the time you see damage the worm is inside the fruit out of reach of your sprays.
After 5-6 years of fruiting trees you may more or less know how things proceed and can use the timing of flowering, petal fall, fruit sizing, etc to indicate where the bugs and diseases are and what needs to be sprayed.
Before getting into spraying, lets talk tree health! Having healthy trees will make the sprays you do apply more effective, and will mean you can get away with fewer sprays. This is primarily for diseases, but healthy trees will also put up more resistance to bugs in terms of how much distasteful compounds or goo they can throw at them.
Number one is having enough sun per day, early sun in particular. I have several plantings lacking this and they are much more prone to rot and diseases. Number two is having the trees pruned and trained well, in particular open enough so that nothing is overly shaded and thus lacking in air circulation. Speaking of air circulation, it really does matter as dew will dry off much faster if there is good air flow - avoid planting in areas which are airflow sinks. Last is the issue of soil. I haven’t found this to be a big factor in my orchard, but if the tree doesn’t have a good balance of nutrients or is too wet or too dry the tree will be less healthy and will have more disease problems. Organic mulch is very important for younger trees, it helps moderate water and temperature as well as supply nutrients. I apply one cup of Tree-Tone per tree each year in case there is some micronutrient that is missing (probably not needed but it makes me sleep better ).
Apples and pears
Here is my apple spray schedule, with comments for pear variations.
Delayed dormant (green tip to pink (description) ): lime-sulphur plus dormant oil.
- For pears apply this at bud swell to nail the pear psylla.
- I prefer soybean or canola oil for dormant sprays, they are heavier than the very light mineral oils which do not smother as well.
- If you had fireblight trouble the previous year replace the lime-sulphur with copper (I use Kocide 3000 but other coppers also work well). Copper is not good long-term for the soil so it is best to use copper only if you had a recent infection. If fireblight is really bad you also may need to apply agrimycin or similar at bloom based on weather timing (a complex issue I am not going to go into here).
Petal fall: Surround, spinosad, sulphur or Serenade/oil. Plus myclobutanil for cedar apple rust if non-organic.
Surround spraying in general: You need to keep a good coat of Surround from petal fall to fruit around nickel-sized. I use 3c per gallon for the first several sprays and after 1" or more rain, 2c per gallon other times. While it is most important to cover the fruitlets, the branches around the fruits also need good coverage as the curculio is mostly walking between fruitlets. The trunk is somewhat less important. You don’t need a glowing white coat on everything, but something like half the surface on all sides should be covered (don’t just hit the tops, the curc will figure it out and walk upside-down everywhere - I’ve seen it). Curculio is most active during warmer nights; if its 50F at night there is no rush to re-apply, but one night with a low of 75F can produce a huge amount of damage.
Spinosad - it is for codling moth but also helps control other problem bugs. Spinosad lasts for a week or less and its a bit of hit or miss how much protection it gives if you are not spraying it all the time (I don’t). Spinosad can have negative impact on bee populations so keep that in mind for spray timing.
Disease sprays are important in spring, this is when the diseases really get going. I use sulphur or Serenade plus oil (alternating) in every tank in the spring, plus possibly myclobutanil once after petal fall. Don’t spray oil if sulphur is still present by smell, and don’t spray sulphur if the oil was put on in the last few days. Serenade and oil can be put in the same tank to good effect. I use Cumulus WP sulphur and Tritek/Monterey Horticultural Oil/Saf-T-Side (same stuff under different names) is my favorite oil as it also smothers diseases.
You don’t really need the myclobutanil on apples unless your apples are right under a cedar/juniper tree - CAR is mostly cosmetic leaf damage, there is little apple fruit damage with CAR. I often skip the myclobutanil. So, its relatively easy for me to grow apples or pears without any synthetics; peaches and plums are much more difficult due to brown rot.
This is also the time to put out codling moth mating disruption, e.g. NoMate spirals, if you can source them (stupid state regulations make them difficult to get ahold of in many states).
For the next month or so, keep an eye out for any apples with a brown spot with frass coming out - that is codling moth, remove that fruit. And when you thin, preferentially remove all the curculio-bitten fruitlets. I thin in several passes so if the curculio comes later I don’t lose the only apple - usually I thin to 2-3 per cluster and a few weeks later take it down to 1.
Next spray: Refresh Surround, spinosad, codling moth granulosis, and sulphur or Serenade/oil.
- When is the “next spray”? Its when the previous Surround is looking thin and some warm nights are coming up. The Surround timing is the most critical, the other things are just piggybacked on the Surround.
- If you see a whole lot of fresh curc damage, you can bet the next spray is NOW!! Get on it!! Be sure you know how to tell the age of a curc bite - fresh ones look like a small crescent was just sliced into the fruits, and older ones are in some degree of healing from that. Look at the same bite over several days to learn how the appearance evolves over time.
- Codling moth granulosis (Cyd-X, Virosoft) gives extra protection against codling moth. It has a similar action as spinosad. It may be hard to find in small quantities.
- Around the 2nd or so Surround spray I sometimes have rosy apple aphid infestations (curled leaves). If it gets bad enough I will take out a small tank of soap and hit each infestation and rub the soap around to get into the cracks. If its spotty I will just prune off the offending shoots and squish - with diligence this is often all that is needed.
Next 2-3 sprays: Depending on how much rain comes etc I will do a total of 4-5 Surround sprays, so 2-3 beyond the two above. With each Surround tank I also include spinosad/granulosis and sulphur or oil. Like above, the Surround timing dictates when to spray and the other stuff is piggybacking on the Surround tank. If the coverage still looks OK and you don’t see a lot of new damage, hold off. If a warm night is coming up and the Surround coat is thin, put more on! Once fruits are nickel-sized (mid to late May for me) Surround stops except for dealing with stinkbugs.
Summer: possible stinkbug sprays.
- Its hot here and I want to do as little spraying as possible.
- Pears can have serious stinkbug issues and if fresh damage is spotted I will hit all pears with Surround (plus a disease preventative while doing the spray; avoid sulphur and oil when its too hot). Surround is very effective at slowing their progress. Some years the apples are also getting a lot of stinkbug damage so a summer coat of Surround will go on them as well. Monitoring for stinkbugs is very important, you will know when they are active when you find damage you did not see the last time and you can hit 'em hard with Surround!
- Many apple varieties need disease sprays for rots in the summer; my approach is to chop down those trees and only grow ones which do OK without any disease sprays in the summer.
Peaches, plums, and cherries
I should write this out but for now here is the stone fruit variation on the above apple schedule. Peaches, plums, and cherries I mostly treat the same except where as noted.
- Skip the granulosis, it is for codling moth only
- Aphids can be a huge problem on cherries (black aphids) and plums (green aphids).
- For the black aphids, paint a ring of pure raw neem oil or tanglefoot a few feet up the trunk to block the ants who move the aphids about.
- For the green aphids, they much prefer the higher shoots; keep a tank loaded with soap and hit them every week or so just on those top shoots. After about a month the ladybugs will have them mostly under control (or so we hope).
- Stinkbugs can be a huge problem on peaches but Surround in the summer also helps with that. As with the pears, keep monitoring and hit them when fresh damage is spotted. They prefer fruits more in the tree interior so make sure to look inside.
- Around dime- to nickel-sized the peaches need sulphur to combat peach scab. Cover the fruits very thoroughly, I can always tell where I missed by the scab (black dots on top) that shows up there. (Note I am always including this with a Surround spray, not on its own).
- Make sure to pick up any stone fruit drops of dime to quarter sized, they are likely curculio-bitten fruits that have a worm in them. Each such fruit you pick up is one less curculio next year
- Rot control. Brown rot is a huge problem in the summer months once your orchard catches it (which can take 3-10 years). It starts out mild but in a few years you have a catastrophe on your hands if you are not spraying.
- Remove all rotted fruits immediately - even a small bit of rot will shortly turn into a fully rotted fruit, get it out!
- Spray sulphur or serenade/oil.
- No, those don’t work horribly well and rot is probably the #1 reason why I am often not fully organic. I use Monterey Fungi Fighter (propiconazole) or Indar (starting 2016) whenever rot appears to be getting out of hand. I do at most two such sprays per year but may start to do more as rot is still a big problem for me.
- As with all other summer disease sprays, combine with Surround for stinkbug control if needed
- Note the best rot control is a saw - I have removed many dozens of varieties that rotted badly; all Euro plums are difficult for me and only the latest ripening ones work reliably. If you are in a rot-prone climate I would avoid any variety known to be rot-prone, its too much spray effort to keep on top of it.
- Bacterial spot: if this is a problem use copper in place of lime-sulphur in the delayed dormant spray, and also spray copper right after the leaves have fallen in the fall, both times at dormant label strength. You also need to prune the trees very open, be brutal on peach trees in particular. The NC videos are a good place to learn the art of open peach pruning. Open pruning is also very important for rot prevention.
- Peachtree borer is a major problem on peach trees. It can take several years before borers find your trees but you are in serious trouble if you ignore them once they show up. Look up how they look and keep your eye out - they are very unusual-looking and are easy to spot. I control them with ease by painting raw neem on the bottom 6" or so of trunk in the early spring. Don’t do this to young (1-2 year) trees as the bark may be too tender. Also there have been reports of neem girdling young apple trees so until more is known stick to stone fruits (I have used it directly on 50+ peach plum and cherry trees with no ill effects).
- Oriental fruit moth (OFM) is the problem moth on stone fruits.
- To tell moth larvae apart from curculio, put them on your hand and see if they crawl (moth) or just flop about (curculio). Make sure you know the difference so you know what your problem is.
- Use OFM mating disruption lures if you can find them, placed out at petal fall.
- Surround and spinosad are also effective, and oil can help smother eggs. I don’t do any extra sprays for OFM beyond what is above, but if I am hitting the stinkbugs the Surround will also set back OFM (and, spinosad will also be included in the tank - up to 6x per year).
- Tip pruning is an important technique to limit OFM populations: when a peach shoot tip is flagged (bent) it means there is an OFM inside; prune off the tip and dispose of it. I would also get in the habit of checking for an actual bug in some tips to know what your pest is. During peak OFM periods (there are several generations per summer) I am regularly monitoring peach tips as I walk through the orchard.
- Japanese beetles can be big problem on plum leaves. Again, apply Surround to where they are causing problems, and consider using milky spore if they are a big problem every year.
- Bacterial canker is a major problem on cherry trees. If the characteristic ooze appears, get a knife and cut out the bark until you have removed all the dark-colored cambium layer. Another method is to use a blowtorch or other flame.
- Black knot is similar to canker in that you want to cut it all out back to clean wood. For both of these diseases you don’t need to cut too deeply, most of the infection is close to the surface. If the limb is small, just remove it, its not worth cutting out. About 90% of my removals of knots succeed the first time, but 10% need another round - keep monitoring.
- Peach leaf curl is something I rarely get. The treatment is similar to bacterial spot, copper in spring and fall, but make sure to put on the copper for curl in the spring before any leaf starts to appear as it may be too late by then.
- Another alternative moth control for both pome and stone fruits is Bt. I have not found it is as effective as the viruses in terms of lethality but I often include some in the tank (I use Dipel WP).
Sources for products
There are many good sources but here are some links in case you can’t find them or to see what I am referring to.
- I get my 25 lb bags of Surround from Seven Springs. Make sure you check the shipping wherever you get it from, its a lot because its heavy. Schlabachs and Peaceful Valley are other places with reasonable prices including shipping on Surround.
- Spinosad in small quantity is Monterey Garden Insect Spray (link is to Amazon listing).
- Tritek type oil in small quantity is Monterey oil (Amazon listing). Bigger quantity from Seven Springs.
- Serenade in small quantity is Bayer Advanced Serenade (Amazon again).
- Nomate codling moth spirals are currently sold by Arbico. They are expensive but a bag lasts 5-10 years for a backyard grower; keep in freezer.
- Nomate OFM spirals. Gemplars only ships these to a few states unfortunately. Similar price and freeze them like CM spirals.
- Most copper and sulphur products are similar. For copper, Kocide 3000 is a bit more effective in terms of how much copper you need to use.
- Lime-sulphur can currently be hard to find due to obscure EPA issues. Seven Springs now sells 2.5 gallon quantity - that will last less longer than you think as you need a lot of it per spray. Its not super hard to make your own if you have experience handling dangerous chemicals. The pet dip version is also supposedly the same compound (but 4x as concentrated).
- There are many sulfur products available, either in liquid or DF (dry flowable) form. Bonide Sulfur is a reasonable DF product; I use a commercial version in larger quantity, check GrowOrganic.com or Keystone Pest Solutions.
- Cyd-X Codling Moth Ganulosis is available in small(er) quantity from Peaceful Valley now. Peaceful Valley also sells many of the other things above. Harmony also sells Cyd-X in the small jar.
- Great Lakes IPM is the ultimate source for lures and mating disruption. Too bad they don’t ship to all states.
- Raw neem can be hard to find, most horticultural neem you find is refined with many of the good compounds removed. Dyna-Grow and neemresource.com are two that have a good reputation. Raw neem can also be used in place of soap or oil for aphids, spider mites, scale, and other small pests, just make sure to add a bit of dish soap to the spray or it will clog your sprayer something ugly. It can be solid at colder temperatures so may need warming up to get it flowing. Keep any you are not using for that season in the refrigerator as it will eventually spoil.