Here is my “low impact” spray schedule, updated from this old version - Low Impact Spray Schedule (old version). This has been refined over about 15 years of successes and failures. My rough guide for low impact is no wide-spectrum poisons, which also means no PyGanic or rotenone. 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.
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 my goal. Sooty blotch is a minor disease, some varieties will get a lot of that.
This is designed for my climate - adapt to yours
Everyone has a different climate with different pest pressures. I am in a fairly hot and humid area, and have some 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, though!
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 or the shoot tip and 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 roughly indicate where the bugs and diseases are and what needs to be sprayed, but for a low-impact spray you always still need to be regularly monitoring as the sprays are weak compared to the synthetics and you really need to be on top of things.
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 lacking in air circulation. Summer pruning (cut any long shoots in half) can be a big help to get more light and air circulation into the areas around the fruits. 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 ). I also use Reglia as a foliar spray regularly as it promotes leaf health and raises disease defenses.
Apples and pears (and a bit on stone fruits)
Here is my apple spray schedule, with comments for pear variations as well as some comments on stone fruits (more below on them).
Delayed dormant (green tip to pink (description) ): lime-sulphur plus dormant oil.
- For pears apply this at bud swell to nail the pear leaf blister mite, a common and bad pest if not hit with this early spray. With this spray, blister mites are nailed for the year.
- 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 or supplement 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). I solved my fireblight issues by removing all late-blooming apples and highly FB-sensitive apples. Also any very late blooms (some trees produce a few) get hand-picked off. Now I only get occasional minor strikes.
Petal fall: Surround, spinosad, possibly other viruses (Madex HP, CM granulosis), Regalia, oil. Plus myclobutanil for cedar apple rust if non-organic.
Regalia is a pro-active disease fighter, it helps plants build up disease resistance. I’m not sure how well it works but I have been using it for several years now.
General Surround spraying tips: Surround is challenging to get the hang of, but it is not impossible. Here is a long list of tips for using Surround on both pome and stone fruits which you may find helpful.
- 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.
- Hit from all sides. I once saw the curc moving upside-down on a branch I sprayed only the top on. Oops.
- Start right after petal fall. If the petal fall times are varying just hit what has dropped petals, don’t wait till all to drop or your curcs will be having a party on the early stuff.
- Base re-application on what the current coat looks like. A little rain often does little, but an inch of rain will wash most off.
- In spring a week of growth can cause a lot more fruit to be exposed, especially with shuck drop, so also monitor how covered the fruits are rain or no.
- Remember the curc likes warm nights. Don’t let the trees sit barren on a warm night!
- You don’t have to make the tree all white but you need a good number of specks on all surfaces of the tree.
- Hit nectarines extra hard, the curc loves 'em!
- The curc doesn’t like to fly as it consumes a lot of energy to do so, it is walking most of the time. So, there will be “hot spots” where you will find many bites, and then spots of no bites. So when thinning, if you find one bitten fruit look in the area for more of them.
- Monitor daily or every other day, checking things out and doing some thinning as you go.
- The more damage you see the easier you want to go on the pace of thinning healthy fruits, to avoid over-thinning if the curc takes too much.
- Some trees the curc just likes more and you will see those and can hit them harder when you spray.
- When looking for scarred fruits in a hot spot it helps to grab the limb and twist it around to look at all sides. Its easy to miss damage thats on the side you are normally not seeing.
- Once the curc worm is into the seed the bitten fruits will start to decline. Look for those smaller yellowing/wrinking fruits and thin them, even if they are not curc bitten they need thinning anyway. Once they drop they are harder to find.
- Speaking of drops, once the curc has eaten the seeds of stone fruits the fruit will start to drop. You need to be vigilant to get all the drops you can as each one will make a new curc which will then wreck 100’s of fruits. At that point you will need to also be collecting any thinned fruits (don’t just drop them on the ground) as you want all the fruit on the ground to be ones to pick up. For apples the curc usually gets crushed and you just get a misshapen apple, and there is not so much of an issue with picking up drops.
- Beware that the curc seems to first be doing minor damage and then one day it goes from nothing to horrible. This is often because a warm night showed up and the curc chowed down. Or you missed a bunch of damage.
- Remember that Surround is just slo-mo juice for the curc, you will still get plenty of damage. But you should have 90% of the fruit OK if you did a good job on the coats.
Spinosad - it is for oriental fruit moth and 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. CM
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 Tri-tek/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 there are cedar/juniper trees nearby - 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. If you have problems with apple scab you may need to be doing a lot of sulphur instead of the oil with your Surround. Personally in my orchard I have few scab problems.
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, immediately remove that fruit and destroy. 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, Regalia 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. Once a good population of ladybugs has developed you may have few problems with this pest.
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, Regalia, and sulphur or oil (usually oil these days, I really like the Tri-Tek 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.
At this point it is early June in my climate – apples are from dime to nickel-sized and the curc is pretty much done along with the first generation of codling moth. I ease up on spraying a lot at this point.
Summer: stinkbug and maybe some summer disease sprays.
- Its hot here and I want to do as little spraying as possible, so the nummber of sprays I do is much fewer, more like once a month.
- 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 numerous disease sprays for summer rots in my climate; I have mostly removed apple varieties which have this problem. If you pick a random apple variety there is about a 50-50 chance it will rot badly in my climate. I have culled hundreds of apple varieties from my orchard for this reason. If you have less brutal heat in the summer this will not be so much of a problem, but if you are in the more hot and humid areas I would make sure to be extra picky on which varieties you choose.
Peaches, plums, apricots, and cherries
Here is the stone fruit variation on the above apple schedule. I in fact often use the same tank mix for pome and stone fruit, so there may be more things in the tank than I have listed as I threw something in there just for the apples/peaches for example. Peaches, plums, apricots, and cherries I mostly treat the same except where as noted.
- As with apples most of the critical sprays are needed in spring before the fruits are nickel-sized. You pretty much need a constant good Surround coat in this period, refreshing after big rains, or you will get damage. This means 4-6 sprays in the spring. Once the curculio has stopped new bites things ease up a bit as far as need for regular sprays, its more brown rot preventative and OFM later generations.
- Above in the apple section I have a lot of tips for Surround spraying as it is hard; take a read through that.
- Apricots are not big fans of sulphur. Some apricots are OK with it, but I had a few problems so I don’t use sulphur on apricots. If you are sharing tanks across apples and stone fruits you will need to keep this in mind, e.g. hit the 'cots and then throw in the sulphur to the tank.
- Skip the granulosis, it is for codling moth only (I in fact often skip the granulosis on the apples as spinosad is similar and will work in one tank on pome and stone fruits).
- Aphids can be a huge problem on cherries (black aphids) and plums (green aphids). They start being a problem in late May or early June for me, be ready for them as they tend to come back every year around the same time.
- For the black aphids, paint a ring of tanglefoot a few feet up the trunk to block the ants who move the aphids about. Also make sure there are no other ways the ants can climb, e.g. a limb from a neighboring tree whose trunk is not coated.
- For the green plum 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 under control.
- Stinkbugs can be a huge problem on peaches but Surround in the late spring and summer greatly 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 and apricots need something to combat peach scab. Either sulphur or various synthetics can take care of that; I am using Indar for brown rot and it also does OK on scab control. Cover the fruits very thoroughly, I can always tell where I missed by the scab (black dots on top) that shows up there. Note that this and pretty much any other spray mentioned here I probably also am putting some Surround in the tank as well, plus maybe other things. Make sure to minimize total sprays by having several different things in the tank.
- 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 and Tri-Tek oil, the latter which smothers rot spores.
- No, those don’t work horribly well and rot is probably the #1 reason why I am often not fully organic. I now use a combination of Indar and Elevate, alternating to avoid resistance. Propiconazole is similar to Indar and is more widely available. I include these in earlier Surround tanks to supress the general level of brown rot and to also deal with brown rot shoot blight, usually a minor issue but some years it can get out of hand on apricots.
- If you do want to be 100% organic I would strongly recommend using lime-sulphur sprays as it is probably the most powerful organic option. Make sure to use the growing season rates not dormant rates.
- As with all other summer disease sprays, combine with Surround for stinkbug control if needed; the Surround also annoys the OFM so its not a bad idea to include at least a small amount throughout the summer.
- 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 OK. If you are in a rot-prone climate like me, 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 for brown frass at the base of the trees in late spring or summer as the sign you have been hit. 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 stick to stone fruits with this treatment (I have used it directly on 50+ peach plum and cherry trees with no ill effects). Currently I am using a 3-way mix of sesame, neem, and raw linseed oils as all three are toxic to bugs and the other two are somewhat cheaper than the neem.
- 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.
- OFM have several generations in a year; in the spring they start somewhat clustered in the generations – there will be a period of about 3-4 weeks when you will see fresh tip shoot damage, then it will be quiet for several weeks with no new damage, then the next generation will hatch and you will start to see more tip (and now fruit) damage. Things tend to be pretty much constant by the end of the summer as the different generations merge into each other. What this means for spraying is hit the first generation hatch hard, remembering that eggs were laid 1-2 weeks before you see flagging tips, and you can ease up a bit when you stop seeing more flagged tips. But, you will need to pick it up later and keep protection going pretty much the rest of the summer after that one break.
- Use OFM mating disruption lures if you can find them, placed out at petal fall.
- Surround and spinosad are also effective, as is Bt, and oil can help smother eggs. In the spring I don’t do any extra sprays for OFM beyond what is above, but if I am hitting the stinkbugs the Surround and Bt will also set back OFM (and, spinosad will also be included in the tank - up to 6x per year).
- Peach shoot tip spraying with spinosad/Surround/Tri-Tek oil/Bt is highly effective at eliminating tip damage. Have an extension wand and get the mist well over the tree so the shoot tips are well-covered. This 4-way combo pretty much eliminates any shoot tip damage and will greatly limit the size of the next generation of OFM. In the spring the OFM are mainly after the peach shoot tips; later generations will target the fruits. Quarter sized or bigger seems to be what they are interested in.
- If you were not good about the above tip spraying, 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. You should also get in the habit of checking for an actual bug in some tips to know what your pest is.
- Through the summer the quarter-sized or bigger fruits will need to be targeted with something like Bt/spinosad/Tri-Tek/Surround in order to limit OFM damage on the fruits.
- 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 once the bad bark has been cut out. On plum it can occasionally also be bad. On peaches it can mostly be ignored as the trees still keep their vigor.
- 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. The “bad wood” to cut out for black knot has this greenish spongy look to it, get familiar with the difference between good and bad wood and cut out all the bad wood plus a small margin into good wood (you can’t take too much margin as you don’t want to cut all the bark off and girdle the branch and kill it). 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.
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).
- Tri-Tek 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. Peaceful Valley now sells 2.5 gallon quantity - that will last less long 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.