Questions not deserving of a whole thread


My peach trees are almost done with blooms, most are are at shuck split or have set fruit. On many of my smaller trees I will only get one to three fruit max due to frost damage When I spray with Imidan can I just spray the fruit or do I need to spray the whole tree? .


What causes wood, specifically graft wood, to be pithy. After grafting many pears and persimmons I have seen how common it is for terminal wood to be pithy. This isn’t always they case, and the diameter of the wood does not seem to correlate with how pithy it is. I’ve seen very pithy 3/8 inch terminal scions and smaller non-pithy terminal scions harvested from the same tree. Is it rapid or late season growth that causes this problem? These scions are more fragile and difficult to work with. Also, they are more prone to insect damage. Perhaps too much fertilizer or bad timing for fertilizer application?


I look forward to the professionals answering you. But I can tell you this. In past years when I’ve lost all my peaches to frost I just didn’t spray imidan at all the rest of the year, but I regretted it very much. What happened to me was that either OFM or PC still hit my trees hard, but since there was no fruit for them they just bore into the tips of every single branch on my trees, then those tips would die. You could cut into them and find the little white larvae inside those tips hollowing them out as the ate the inside. The worse part about this is that thanks to the life cycle of the insects, just about the time the old, dead tip was being replaced with new growth, they would once again drill an egg into that new tip which would become a new larvae which would hollow out the inside and kill that new tip- repeating the cycle over and over. About every 3 weeks I’d have all the tips on my peach trees die. Well, since mine (like yours) were mostly small trees, the end result is my trees were able to put on very little new growth that whole season. I felt like I pretty much wasted that full year of growing since my trees were very little larger by end of season than they were at the beginning, and for fast growing peach trees that is pretty shocking.

I have incredible insect pressure here and I’ve heard others say they don’t loose as many tips as I did, but in my case every single branch- large or small- would have a dead tip on it. The whole tree would have wilted and then brown tips all over it every 3 weeks. Not sure it that will happen to you, but I thought I would tell you what happened to me when I didn’t spray my trees. Good luck.


The shoot tip damage “flagging” on your peach trees were caused by OFM only. PC don’t do that. OFM has 4-5 generations in one growing season. I see such damage on my tree way into late Sept. PC only has one or two generation a growing season.

@SpudDaddy, if you have OFM pressure in addition to other pests, you may want to spray the whole tree since OFM will damage the shoots, too. However, I primarily want to protect my fruit.

I am neither professional or very experienced so take it with a grain of salt. @Olpea would be the man to ask.


@SpudDaddy @thecityman Same happened to me last year when I decided not to spray until I see the insects, so after the first wave of dead shoot tips, I sprayed regularly with Sevin, malathion and esfenvalerate till Sep. In Sep I thought I’d spray my nectarines only (I have no peach) so I ended with numerous dead shoot tips on my pluots and cots. This year, I will spray all trees prophylactically throughout the season. One thing to note, it is recommended to rotate insecticide class, i.e. don’t use the same class twice in a row.


@mamuang @Ahmad @thecityman Thanks for all the feedback and suggestions. Last year was the first year that I really had a large peach crop (by my standards). I definitely had PC damage with the crescent scar. But I had a lot of holes in my fruit that were not crescent shaped so I assumed it was some type of moth. I did not have dead shoot tips last year so is my logic right that I did not have OFM damage but Coddling Moth? What is the generation(s) for CM? I am not crazy about spraying Imidan and had hoped to do it only 2 to 3 times after my fruit set (penny size). I travel a lot (I am traveling now) so it is difficult for me to spray on a regular schedule, this weekend will be my first chance. I am not crazy about spraying for OFM all season but I guess I will have to adjust my thoughts on my spray program.


@SpudDaddy May be if you add sticker, that will help for reducing your spray frequency. I sprayed all season not only for OFM, but for all the other bugs/diseases that attack the trees. For the past two years, I tried reduced spraying frequency, but the trees got hit hard with various pests/diseases. I figured if I live in the warm humid North East, I have to spray regularly, otherwise I may forget about getting good fruits and stop growing fruit trees all together.


With our wet, cool springs, natural pollinators are often in short supply and late to get busy, even with 6 Mason Bee hotels in my backyard. I give my kids a couple of Q-tips and the 3 of us “play bee” in the garden for a few minutes, two or three times a week in the spring until the pollinators are more active.


Spraying frequently is not as effective as spraying at the right time. To know the right time, you would need to monitor the movement of those pests esp. their emergence.

Also, when it is recommended to rotate insecticide classes, often it’s meant for commercial orchards that use the same chemicals in a large amount over the years. I doubt if you need to rotate your insecticide if you have a young orchard and not many trees.

@SpudDaddy I am nervous about Imidan because the label says not to use it in a residential area. I live in a densely populated neighborhood. I cannot use Imidan and will not be happy if my neighbor use Imidan in their backyard near my home, either.

Look up @scottfsmith’s Low Impact Spraying Schedule in the Guides category for ideas. You may be able to modify his suggestion to suit your orchard needs.


I follow the spray schedule recommended by Penn State Extension for home orchards (screen shot of it below). Regarding insecticide class rotation, this is the advice I got from a friend of mine who is a Ph.D. entomologist specializing in the development of insecticides. He recommended that in general, but especially for insects that would have multi-generations in the same season (like OFM).

Note: Yellow highlights are from me.


I read a lot of advice and recommendations from Penn State and Cornell (east coaster here) as well. Then, I try to modify it to meet my needs and level of chemical tolerance. I may not have 100% protection but I use less chemicals by choice.

For someone who wants full protection and don’t mind using various chemicals, your list would fit his/her need.


Anyone know what kind if bloom this is? It is from a tree, and not a bush. It kinda reminds me of honeysuckle, but I know that’s not it.


whatever it is,it is very pretty. Does it have any scent?


No, it doesn’t have any scent to it. The bark reminds me of a cherry, kind of dark gray, with rough dark horizontal ridges on it. I don’t remember it flowering last year, but it is a tall tree, about 15ft high. Most of the blooms are high up in the tree, but these were on a sucker branch that is lower to the ground.



PC frequently doesn’t produce crescent scars on peaches (though sometimes they do). They almost always produce scars on plums/cherries. You can identify a PC grub pretty easily because it’s legless vs. OFM and CM which have some legs.

Codling moth don’t attack stone fruit and don’t cause flagging. OFM attack primarily stone fruit but will also attack pome, particularly where both kinds of fruit are grown together. OFM also attack the shoots.

As Cityman pointed out, OFM pressure can be high causing tree damage. My advice would be for now, just to spray the fruit, since you have so few fruit to protect. Then watch for flagging. A tree will tolerate a little flagging and creates a little bushier tree. If it gets excessive, as it did in Cityman’s case, you’ll just have to spray the whole trees. Otherwise a little quart spray bottle would be fine.

Be aware that Imidan breaks down quickly in alkaline water, so you’ll probably need to acidify the water, if you want to keep the spray you don’t use. It won’t last forever in acidified water, but will last a lot longer.

Imidan has good residual protection on the tree. It retains an insect lethal residue for a couple weeks unless rain has washed it off.


I respect the credentials of your Ph.D entomologist friend, but unless he is also a fruit tree specialist, I think he’s a little bit out of his area of expertise (even if he is a fruit tree specialist, I think he’s being a little OCD about insecticide rotation). Certainly most labels of commercial insecticides recommend insecticide class rotation, but I’m not aware of a single home owner fruit tree insecticide which does.

Tippy is correct that rotation is meant for commercial orchards. There is a vast difference between a commercial peach grower like Titan Farms with 5000 acres of peaches and a backyard grower with 5 peach trees. The risk of the backyard grower producing a resistant strain of insect by way of spraying practices is pretty much non-existent. The numbers just aren’t there.

Additionally, most rotation programs don’t advise rotation with every spray. The current thought is to rotate insecticides with each new generation of insects, monitored via IPM practices like trapping, degree day calculations, etc.

There is perhaps one advantage of rotating insecticides for a backyard grower. That is, if there are some resistant insect pests in the area, a rotation could provide better control over using one insecticide, if that insecticide happens to be the compound which the insect has resistance to.


Sounds like a lot of Imidan for 125 small trees! I use Imidan too, but some portions of the product label concern me, mostly the 14 day re-entry period for the general public. Imidan is the only product that I use with that restriction.

Actara is almost as effective as Imidan for most insects on Apples/peaches. It has a Caution label and fewer restrictions than Imidan except for the longer PHI. Unfortunately, Its really hard on bees. Its a little less than $100 from Martins produce. I’m not sure if the label prohibits its use in a home orchard.


Doesn’t it help to rotate because also because each one has somewhat different mode of operation, lifetime, kickback, UV tolerance, etc? It might not make a lot of difference but it could make some. I am going to be rotating several things in my brown rot spray program this year primarily for that reason.


I wish I could find a useful chart listing the modes of action of common fungicides

For rotation, shifting among modes of action would be best, but I can’t find a good listing


I think there are cases where a grower is battling different stages of a pest (i.e. some insecticides have best activity as ovacides) or where things like rescue sprays are needed (i.e. kickback), or where wash off might be a concern in one part of the season, but not another part (as some pesticides are more prone to wash off than others, just as some pesticides have lower UV and temperature tolerance (and are best used early season)) then rotation would be a good idea for those reasons, no matter how many trees one has. However, most (not all) home growers aren’t that sophisticated, and of course that has nothing to do with resistance.

I think backyard growers who are closely tweaking/monitoring their spray program, might well benefit from some of the more sophisticated strategies you mention.


I do not, I use stronger fungicides for brown rot. The schedule mentions using captan near harvest and I have heard that for brown rot it really only works on the first stages like stem blight, and not well on fruit. Plus it eats my leaves fairly well, which are under Japanese beetle pressure too. So I don’t like using captan late in the season. I still use it early though. I have found it doesn’t work at all if not in acidic water.

Yes, an maybe labels don’t but extension services advise rotation of fungicides for brown rot for the home orchard such as this Wisconsin builtin mentions. Which confirms your statement.

I have read extension service bulletins that do, but it was concerning the use of pyrethroids and suggested rotating use to avoid mite infestations. So I do use a pyrethroid and rotate it’s use.
I like using it because it is effective against PC, and is not very toxic. You can use it legally in the backyard too. You could also decrease toxicity by using a Pyrethrin instead. Pyrethroids tend to last a long time and can accumulate in the environment.