Fungicide application frequency

[Lazylightningny]

We've had discussions about the merits of various fungicides, but I don't see a thread on how often we spray. Questions to discuss:
- When do you begin spraying?
- How often do you spray?
- Do you spray with the same fungicide throughout the season, or do you alternate between different ones?
- When do you stop spraying?
- What do you use to spray?

This is what I do (or rather, with the best intentions, try to do):
- Spray in late winter to prepare for the season.
- As buds begin to elongate, I spray weekly until all leaves are fully open.
- Then I spray monthly thereafter.
- I normally alternate between several different fungicides in order to kill/prevent resistant strains.
- The last time I spray is just before I place the plants into the poly tunnel for winter hibernation.
- I have one of those big 5 gallon backpack-style sprayers. I usually mix up 1.5 gallons at a time, and that seems to be enough for one go-round with all my plants.

Anyone with personal knowledge, what does Boon do? Or Ryan, or Bjorn and other pros?

 

[Forsoothe!]

Follow directions on the label. Don't do preemtive aplications unless you know you have a continuing problem. In a word, don't overdo anything.

 

[BonsaiDawg]

We've had discussions about the merits of various fungicides, but I don't see a thread on how often we spray. Questions to discuss:
- When do you begin spraying?
- How often do you spray?
- Do you spray with the same fungicide throughout the season, or do you alternate between different ones?
- When do you stop spraying?
- What do you use to spray?

This is what I do (or rather, with the best intentions, try to do):
- Spray in late winter to prepare for the season.
- As buds begin to elongate, I spray weekly until all leaves are fully open.
- Then I spray monthly thereafter.
- I normally alternate between several different fungicides in order to kill/prevent resistant strains.
- The last time I spray is just before I place the plants into the poly tunnel for winter hibernation.
- I have one of those big 5 gallon backpack-style sprayers. I usually mix up 1.5 gallons at a time, and that seems to be enough for one go-round with all my plants.

Anyone with personal knowledge, what does Boon do? Or Ryan, or Bjorn and other pros?

Read the goddamn label!!! Read the label. Read the label. Read the label.

 

[Lazylightningny]

Follow directions on the label. Don't do preemtive aplications unless you know you have a continuing problem. In a word, don't overdo anything.

I have recurring problems with powdery mildew, leaf spot, and am starting to see apple cedar rust on my junipers. I disagree with not doing pre-emptive spraying. I think it's important.

 

[Lazylightningny]

Read the goddamn label!!! Read the label. Read the label. Read the label.

Don't be a smartass. Have some courtesy.

 

[BonsaiDawg]

Don't be a smartass. Have some courtesy.

Yes thank you you're right. I will edit my post. We'll I guess it's too late. My apologies Lazylightningny.

 

[Lazylightningny]

Yes thank you you're right. I will edit my post. We'll I guess it's too late. My apologies Lazylightningny.

No problem. Thank you for the apology.

 

[Oleg]

I use Monterey Fungi Fighter for preemptive a application against CAR, Propiconazole is the active ingredient. It is systemic and lasts for months, prevention is the only course with CAR you have to prune and dispose of everything that gets it. I have used it for 4-5 years and have had no CAR since. I have a Chestnut that gets Horse-Chestnut Leaf Blotch (Guignardia aesculi) every year I just found out spraying with the same before leaves mature will stop it from infection several months down the road, I'm very optimistic about trying it this year.
https://collections.ola.org/mon/2000/10297273.pdf
This article covers a lot of pests.
Good luck!

 

[Forsoothe!]

I have recurring problems with powdery mildew, leaf spot, and am starting to see apple cedar rust on my junipers. I disagree with not doing pre-emptive spraying. I think it's important.

Don't do preemtive aplications unless you know you have a continuing problem.

Keep records on when the onset of this or that are in your micro-climate. For instance: Here, in SE MI if I don't spray my dogwoods when they still look good by the second week of June, then when the first hot spell arrives on or about July 1st, they explode in mildew. Then, it's too late to do anything. Bugs follow weather, too.

 

[Wires_Guy_wires]

Most fungal spores germinate after 8-14 days after landing.
You don't want to treat the spores, you would want to treat the living fungus, since the fungicide only works on the living fungus.

Doing weekly sprays seems too much. Since the fungicides tend to break down slowly, and since spores take more than a week to germinate.
Antibiotics can, and will, mess with physiological plant processes when over used.

I dealt with needle cast, and apple cedar rust with systemics in the past. Now it's trichoderma viride, Copper sulphate and peroxide I'm using, instead of antibiotics. I'm saving the antibiotics for when there's an infection I can't combat any other way.

When I used systemics, I used them twice in spring; at bud break and at elongation when the needles were out. And once again in fall.

Ever since I laid down a ground cover with some collected forest soil and heaps of pine bark, none of the pine related issues ever returned. I think the biosphere in my backyard is producing its own antibiotics now.

Ever since I started using Trichoderma viride, the mildew never returned.

 

[just.wing.it]

I have been known to use Neem before bud break....some Daconil once this year. That Daconil use was about a month ago and I still see the residue on the foliage.

I don't really like spraying shit and potentially harming pollinators so my new bit is to find out what grows in my yard with minimal to zero fungal issues....with that said I'm DONE with J Maples and Tridents....trying a bunch of Acer Rubrum now, all small so far.

Seems like I may have an issue with pines too, they always get sick somehow, JBP, Mugo....

 

[River's Edge]

We've had discussions about the merits of various fungicides, but I don't see a thread on how often we spray. Questions to discuss:
- When do you begin spraying?
- How often do you spray?
- Do you spray with the same fungicide throughout the season, or do you alternate between different ones?
- When do you stop spraying?
- What do you use to spray?

This is what I do (or rather, with the best intentions, try to do):
- Spray in late winter to prepare for the season.
- As buds begin to elongate, I spray weekly until all leaves are fully open.
- Then I spray monthly thereafter.
- I normally alternate between several different fungicides in order to kill/prevent resistant strains.
- The last time I spray is just before I place the plants into the poly tunnel for winter hibernation.
- I have one of those big 5 gallon backpack-style sprayers. I usually mix up 1.5 gallons at a time, and that seems to be enough for one go-round with all my plants.

Anyone with personal knowledge, what does Boon do? Or Ryan, or Bjorn and other pros?

For trees that are susceptible to fungal infections I prefer preventative measures on a regular basis. Timing based on known cycle of risk and dosage based on label. ( calculated for Bonsai specifics ie: container size, tree size etc.)
For known insects and fungal infections that are present in my local surroundings and can be fatal to my trees I prefer systemics used according to label. Application is usually twice per year for consistent resistance. Eg: Infuse for red band needle cast affecting pines. Bayer three in one for Borers.
Note: I live in a forested area with ever present natural insect infestations and fungal issues, considerably different from the city environment.

For any other occasional incidents I use horticultural oils, lime sulphur, water spray, increased sun and or air movement ( location change). All the preventative measures from normal husbandry rather than chemical treatment. Change of soil components, watering routine, PH adjustment, tweezers, scissors etc.

The most important adjustment I believe is to continually select trees that are more compatible with my climate and care routines!
Just my 1 1/2 cents worth after exchange.

 

[just.wing.it]

As far as label recommendations....
I see many labels give you a specific concentration to use based on a square footage of area....anyone know what the hell I'm saying?

Because of that, I usually just wing it.

 

[Lazylightningny]

I'm DONE with J Maples and Tridents....trying a bunch of Acer Rubrum now, all small so far.

Amen to that brother. I've battled powdery mildew on all my maples for years. It's time to give it up.

 

[BonsaiDawg]

Steve how much rain do you get in the spring?

 

[BonsaiDawg]

Amen to that brother. I've battled powdery mildew on all my maples for years. It's time to give it up.

What about just using a general broad spectrum like mancozeb and starting a program before the mildew usually appears each year?

 

[Lazylightningny]

For known insects and fungal infections that are present in my local surroundings and can be fatal to my trees I prefer systemics used according to label. Application is usually twice per year for consistent resistance.

The most important adjustment I believe is to continually select trees that are more compatible with my climate and care routines!
Just my 1 1/2 cents worth after exchange.

I used to think that systemics were illegal in NY, but I went to a Cornell University web site that listed systemics that are legal in NY.

And the second point is well taken. As stated above, maples just don't do well in my area.

 

[Lazylightningny]

I use Monterey Fungi Fighter for preemptive a application against CAR, Propiconazole is the active ingredient. It is systemic and lasts for months, prevention is the only course with CAR you have to prune and dispose of everything that gets it. I have used it for 4-5 years and have had no CAR since. I have a Chestnut that gets Horse-Chestnut Leaf Blotch (Guignardia aesculi) every year I just found out spraying with the same before leaves mature will stop it from infection several months down the road, I'm very optimistic about trying it this year.
https://collections.ola.org/mon/2000/10297273.pdf
This article covers a lot of pests.
Good luck!

That's an extremely thorough article. I bookmarked it. Thanks.

 

[Lazylightningny]

when the first hot spell arrives on or about July 1st, they explode in mildew. Then, it's too late to do anything.

Quite true. Once the mildew comes, you can't get rid of it. You have to prevent it. I've only had marginal success. I've been able to keep it off my prunus, but not my acers. I'm not being diligent enough in my summer spraying.

 

[Lazylightningny]

Steve how much rain do you get in the spring?

I see you live in Seattle. I used to live across the lake in Kirkland Funny thing is, we get more rain here in NY than you do, but it comes heavier and less frequently. Not as many cloudy days with drizzle as you get. Although as a lifelong Seattle resident friend of mine liked to say, we don't consider drizzle to be rain. It's just very high humidity.

What about just using a general broad spectrum like mancozeb and starting a program before the mildew usually appears each year?

I use a variety of fungicides, mancozeb included. I've never tried systemics because I always thought they were illegal here in NY, but I may try a Bonide systemic this year. I was told years ago by someone to spray before bud break, and again as leaves are opening, because the new leaves pick up fungi from the branches. That made sense, so that's what I do. My problems always come in late summer though, when the powdery mildew comes. By then, I've usually gotten lazy about spraying and the mildew hits me hard. It's totally my own fault.