Black Knot (GROWTH on Plums and Cherries). Worst year ever. How to avoid a repeat.

[@trollforge]

I've always used a smallish cardboard box to collect the off cuts, then cuttings, black knot, box and all go into the wood stove. Is that the correct disposal procedure?

[@StefanSobkowiak]

Thats great. A little extra fuel for the fire.

[@marieleopold1625]

I CAUGHT what you TAUGHT on the brown ROT and the black KNOT...so now I'll give it a SHOT! GOOD INFO Stefan, as always. I appreciate the simplicity and 'humility' = (irrigating too early = wet roots and grumpy trees)! Seems you have a LOT of KNOTTY work to do! A bit of work for ALL your ENJOYED blessings. Thanks for the vid and God Bless you and yours!

[@StefanSobkowiak]

Oh now rereading I see your poetry in motion. Good one.

[@angelab4652]

This year it is bad in kkkanada. PNW. Burn the dormant spores and branches right?

[@karenm5681]

Thank you! I'd been wondering what this was on my neighbor's plum tree. I'll be sure to pass this info along and maybe even help her to prune it!

[@carolinesgarden1673]

I dont live in your zone(mine is 8b) but I work in the nursery landscape business. People dont cut back "far enough" not realizing infection in a branch is beyond where it is visible. One question, I deal with some funguses that are "contagious" if you dont sterilize your cutters. I'm assuming black knot isn't contagious.I enjoyed watching ! You gave excellent instruction!!

[@StefanSobkowiak]

We have definite dormant seasons in the North where no diseases are transmitted. No need to sterilize for a few months.

[@EuroYardService]

@@StefanSobkowiak I'd still suggest sterilizing just to be sure, especially when the cutting edge has touched the knot.

[@CashNYC]

Great info just found out about this in summer 2023 gonna deal with this in the winter

[@johnphelps4113]

I have it on my plum cherry and tried Black Knot Begone and a spray....didn't work. It's just easier to whole tree out.

[@SG-ce7ji]

Thank you so much🙏

[@billybobbarker3175]

Thank you. I have four mature Schubert chokecherry. Trunks are up to 12” diameter. The past 4 years blacknot has moved in. Each year I have been pruning away 20-30% of the branches to remove the black knot. I am winning, I think, but it is an every year thing now. Doubt that will ever be knot-free again. One tree now has it on the trunk about half way height. Really bummed about that one. Can I gouge/carve it out and treat the wound somehow? Or is there a fungicide to apply to that spot? Can I save the upper part of the tree or does it have to be chopped off? 😢 The trees are 16 years old and otherwise are maturing well getting nice and thick. But for all of the heavy pruning.

[@StefanSobkowiak]

Schubert is very susceptible to knot.

[@drdaveyjones6216]

My Uncle has successfully controlled black knot by using a blow torch on the affected areas.

[@petepenn1]

Thanks Stefan, looking forward to pruning and planting. Do you have any cuttings for sale? We are in Morin Heights and would take a day to come visit. Will bring fresh baked goodies for all foodies!

[@StefanSobkowiak]

We could. I don’t usually sell cuttings, we have rooted cuttings for shrubs and some plum trees.

[@ianmacrae4963]

Thanks for the instructions. I wasn't sure how much of the limb or branch to cut so now I know. Plus I was about to go at it but wanted to confirm winter was a good time and it would seem so. Hope 2021 is better for Black Knot!

[@melodyscamman244]

Thank you... Think my plums might be beyond saving... The soil they're in is not wet...but it is quite shallow, finding ledge three feet down. I'd planted them along the "road" down to the garden

[@StefanSobkowiak]

If ever you try them again you can raise the soil to give their roots a bit more space.

[@coolmantoole]

Some rootstocks are more tolerant of shallow soil than others. As long as your climate is not too cold for Chickasaw plums (P. angustifolia) you could try grafting Chickasaw cultivars as well as Asian plum cultivars onto wild Chickasaw plum rootstock. If your climate is cold you could try sand cherry rootstock. If your climate is apropriate for European type plums and you want to try those, consider a naturally dwarf variety like Mount Royal and try dwarfing rootstocks. But for Asian and North American type plums I really do think Chickasaw rootstock would be the way to go in a hot climate and sand cherry would be the way to go in a cold climate on account of the shallow nature of those species' root systems. Just be aware that a plum trees with a shallow root system wont be well anchored, so if the rootstock does not have sufficient dwarfing effect on the scion the tree will need to be kept small through pruning. As long as the shallow soil doesn't get too wet or too dry, which they tend to do, I'm pretty sure there are some rootstocks out there that will work for you. It's just a matter of figuring it out and learning how to graft which isn't as hard as it sounds, especially with plums.

[@melodyscamman244]

@@coolmantoole thank you... I probably won't put Plums in the same location...might try sour cherry for cooking or hazelnut... Will put the plums lower on the property... On the zone 5/4 border

[@helengren9349]

@@melodyscamman244 Sour Cherry are delicious as candy🤤 😍 just dry them & they'll last longer 👍

[@rickpederson1219]

Be very careful to sterilize your cutting tools if you cut into the black knot

[@fiorevitola880]

Could you burn the branches or would it get air born and effect the orchard?

[@StefanSobkowiak]

Burn, trash, or hot compost.

[@calebread6966]

Great video Stefan, thank you. Do you find differences in susceptibility amongst your different varieties? For example, do sweet cherries get it as bad as sours? Do the mont royals get it the same as say shiro? How about the romance series cherries?

[@StefanSobkowiak]

Shiro and romance are immune to it. Yes there is a range in tolerance. Most sweet cherries do not get it as bad as some of the plums. Unless others have found it otherwise.

[@agbtg6292]

@@StefanSobkowiak My Shiro wasn't. I heard Japanese plums were resistant but I also lost a Methley plum. I haven't tried it yet on the trunks of plums but for chestnut blight you can suffocate the fungus with mud wrapped with plastic similar air layering except using mud instead of peat moss. You might have to keep adding water to the mud pack during a dry season.

[@beebob1279]

I used to watch the orchardist at one of my bee location prune in late winter. Boy did he know his stuff. He always worried about the plums even though he only have a small group of them. Same thing as you, disease was his big concern.

[@StefanSobkowiak]

Disease in plums is usually an indicator of too much water or insufficient drainage. Plums need excellent drainage and almost only rain.

[@angelab4652]

A lit of rain here. In PNW. Fruits are bursting on the tree. Plums apricots

[@angelab4652]

Famtastic! So then you burn those branches cuz not good for compost?

[@StefanSobkowiak]

Or trash

[@roccoconte2960]

Stone fruits seem to get more deseases than core fruits , black knot , gumoses , brown rot , just to name a few i gave up on most fruit trees , only ones i have success with in my area is european and asian pears.

[@StefanSobkowiak]

Sound like your soil is too wet or poorly drained for stone fruit. Pears are at the farthest end of moisture tolerance while stone fruit like it driest.

[@roccoconte2960]

@@StefanSobkowiak where i live there were fruit orchards planted in the late 1800s until early 1900s, the orchard was Pears and Cherries, i believe there are a lot of pests and deseses left over in my area from the old orchard.

[@debbiewood7718]

The water table in my acreage subdivision has been very high for the last 6 years or so. For 2 winters the sump pump ran all winter. As a result the area is badly infected with black knot. I cut it out of my yard but the neighbors have not cut it out of their Mayday trees. I want to plant fruit trees but i am nervous they will not survive. The water table is going down now, the pump has already stopped and it is only July. I have very sandy soil. My goal is fruit for my family so I only need a few trios. Thoughts? Advise?

[@StefanSobkowiak]

Sandy soil with a high water table is great, you just need to plant your fruit trees on berms. More work but you’ll have healthy productive lower maintenance trees in the end that are self watering.

[@debbiewood7718]

@@StefanSobkowiak Thanks Stephan. Do you expect that a berm will reduce the vulnerability to black knot while it is so prevalent in my neighbourhood? I am thinking a berm made of a mix of peat moss and composted cow manure on the sand would work well.

[@werrew1379]

Thank you sir what will you recommend spraying our plum tree after removing the black knot fungus our tree is full of it and i found your advice very helpful Thank you

[@Latina4Life]

I just found your channel and I'm learning lots. My plum trees are both filled with this stuff....I think they are too far gone. I obviously didn't cut enough....its Spring now, can I cut the branches without killing the tree?

[@StefanSobkowiak]

Yes

[@bc1014]

For black knot on the trunk, could it be sprayed then wrapped with saran wrap possibly suffocating it?

[@StefanSobkowiak]

Try it, it’s possible. We’ve found clearing all Spurs on the trunk solves the problem of knot on the trunk.

[@foodsgoodfarm2429]

what do you do with the prunings? can you burn them? I have ALOT of black knot in the wild cherries in the hedgerows and I've been slowly cutting it out.

[@StefanSobkowiak]

Burn toss or hot compost.

[@0100000101001100]

Thanks. Are there any sprays to help prevent this?

[@StefanSobkowiak]

Whey. Covered it last summer. kzbin.info/www/bejne/gXarZY2br8qknJY

[@chilipepper76]

Thank you! Will take care of my tree right away

[@Skashoon]

I really must find a source for whey. There are no cheese makers anywhere nearby. Perhaps I’ll need to raise a dairy cow, but I sure don’t want to milk it everyday. Hopefully there’s another source. Any ideas?

[@StefanSobkowiak]

Yes look at my whey video comments there were many good alternatives mentioned.

[@erikjohnson9223]

I do a little marquetry as a hobby, and love the color & texture of Prunus serotina wood, and find the trees themselves attractive and to be nice butterfly hosts. But all the (closely related) chokecherries (P. virginiana) in my neighborhood have black knot. There is no way I could prune it out of a 60' black cherry tree. I assume then that susceptible plants (European plums, probably cultivated cherries) should not be grown (or only grown pruned low, with regular, sacrificial pruning to remove incipient infections) where wild hosts like P. serotina are nearby? Question for Californians, Mexicans, etc, who watch this channel (if any--very different climate): does the capulin cherry (P. serotina capuli = P. salicifolia) also get black knot? (Although it is very hard to find improved cultivars of that in the US, I am interested in it as a cherry substitute for folks in FL. Florida is always wet. Not much can be done about that.)

[@StefanSobkowiak]

Good to know and consider the height factor.

[@sandyhanlon3284]

Hello, I noticed yesterday the vast majority of our purple plum had many black knots. My husband and I cut off a lot of the tree and then more in order to get it shaped up. It is about 6 years old. We live in northern Ohio. This is December 10 that we did this. My concern is that it will not have time to heal. Will the winter winds and temps cause harm to the tree? Thank you.

[@StefanSobkowiak]

No for smaller branches. Leave the trunk cutoffs to mid winter.

[@moealles7280]

Watched a good dozen of other videos on this subject and this one is the best! My single plum tree had been neglected for decades and had this black knot thingy. I aggressively pruned. all I could reach by ladder not seeing any above. 1. What about all those green patches along the limbs and branches? Should I use a fungicide and if so what? Also 2. This tree sends up shoots out of the ground all around the area. If I cut them they grow back multifold. How do I get rid of them?

[@StefanSobkowiak]

Get rid or reduce suckers with a cardboard layer and mulch over them. Cut or better dig the suckers out first. For the green thingys they are unripe black knot, cut them off also so you will start the tree fresh next year.

[@altajohnson6513]

My Bing cherry has brown rot. Very few cherries every year. So sad! What to do? My horticulturist friend told me spray with copper.

[@StefanSobkowiak]

Check out my 'whey' video. Works on all fungal diseases.

[@kirstenwhitworth8079]

💖 Thank you so much. This is excellent information. 💖

[@tomstarott]

So it's now 13 months a new season. How much black knot do you have? Did you get less by not irritating early? Do you have drought conditions to have to resort to irrigating trees?

[@StefanSobkowiak]

We have beach sand soil. The amount of black knot varies with the year and the amount of rains.

[@billrichards4024]

Ty for all these videos I enjoy every one I’ve watched

[@doreenmaggio3624]

Thank you So Very Much . Everyone else told me to to dig them and toss them . I did what you demonstrated and this spring my ornament plums are alive and thriving . I appreciate and respect your advice and I can’t thank you enough

[@StefanSobkowiak]

You’re welcome

[@markwalker8589]

Plant new plum trees every few years, cut down and burn badly infected trees your lucky to get 10 years out of a plum

[@StefanSobkowiak]

Wow.

[@hippiechickoffgridmaine8625]

Thank you!

[@njgrplr2007]

Our purple plum tree was in pristine condition for years but I recently found black knot fungus throughout the tree. I pruned every infected branch and wound up giving the tree quite a haircut. Since this is the only plum tree within 100 yards I assume the black knot fungus was transported to my tree by birds just like the fungus that afflicted the American Chestnut tree in the early 1900s. And if that's the case, what stops it from coming back even if I spray the tree with fungicide?

[@StefanSobkowiak]

It’s a naturally occurring fungus on native trees, mostly cherries. A cleanup is good. Now focus on why you had it, usually excess water in the soil (poor drainage), or lack of aeration in the tree due to tree density in surroundings. It should be regarded as an indicator. I will be working on tree nutrition solutions in next years.

[@njgrplr2007]

@@StefanSobkowiak Thank you for the response. Now that you mention it, I did water the plum tree a lot more than in previous years. I'm not sure if it is contributing to the problem, but I put black mulch around the tree this year whereas it had big white stone surrounding it in years past. In other areas of my yard, the same mulch produced a lot of mushrooms. The plum tree is one of two trees in my front yard and they each have a lot of room to themselves. What can I do to improve aeration? I was thinking of using a fungicide in early Spring. If this is advisable, which one would you recommend? Thanks again.

[@coolmantoole]

Thank you for this. For some reason I've escaped black knot problems with my fairly large collection of Checkasaw cultivars and cherry plum hybrids. I don't know whether I'm just lucky or if the stem canker resistant varieties I have to grow are just super resistant to black knot as well. Somehow I instinctively realized that I needed to clean the stove pipe on my cherry plum trunks. (Chickasaw plum trunks are naturally pretty clean of twigs and fruiting spurs. But to be honest, I wasn't thinking of black knot. I was thinking in terms of bacterial stem canker and the need for the trunks to dry out quickly between our daily thunderstorms in July and August here in SE Georgia. I will add a caution to southern growers. You want to keep cutting on a fully dormant stone fruit tree to an absolute minimum in our high stem canker climate. The tree has zero natural defenses against stem canker when it's fully dormant. The time to prune is between bud break and when the bloom buds are developed enough to be too easy to knock off. I clean the trunks right after harvest which happens in May and June here but before the daily rains that often hit in July and August. That way the trunk is clean and the canopy is opened up a bit for the season when the tree really needs to dry out quickly.

[@erikjohnson9223]

Japanese and perhaps P. americana and P. nigra cultivars and hybrids are immune. European plums are less susceptible to brown rot but more susceptible to black knot. Although Chickasaw plums are not commercially important and therefore seldom commented upon, I suspect that they have similar pathogen resistance patterns as other native plums.

[@coolmantoole]

@@erikjohnson9223 LOL! The amazing thing is that the Chickasaw plum cultivars are a thousand times better tasting than the American or Canada plum cultivars. However, I'm in an Atlanta area gardening FB group even though I'm in the southern part of Georgia and have a very different climate and soils from the Atlanta area. Recently a woman there had a Guthrie Chickasaw plum to suddenly get hit very hard with black knot. So that particular Chickasaw cultivar is definitely not immune, and it the one that that's the easiest to find at online nurseries. A note about brownrot. We have terrible brown rot pressure, and some of the Chickasaw cultivars are quite susceptible to it. I have a NC McKibben to ripen fruit for the first time this year, and I would say that I lost two thirds of the crop to brown rot even though I'm careful about orchard hygiene and spray regularly with liquid copper. I will have to find something a little stronger for this tree to do me any good. But the tree that was even worse until stem canker got it was the green gage. I had to harvest the plums while they were hard and very green to get any plums at all. And no fungicide seemed to make any difference.

[@SA-lr1sf]

That is what takes the fun out. Is there a plum tree that doesn't get black knot?

[@StefanSobkowiak]

Here's a table of different plum cultivars and their susceptibility: www.omafra.gov.on.ca/IPM/english/tender/diseases-and-disorders/blackknot.html#advanced

[@bountywoodsfarm8594]

Do you not have a problem with it spreading when you don't disinfect the secateurs between cuts? I was told to disinfect every time with bleach or similar, but it would be much easier not to have to do that, even if there were a few re-infections.

[@StefanSobkowiak]

First we prune when the trees are dormant, so nothing spreads. Second we don’t cut into the knot but below. Third the knot itself is dormant and not ‘open’ to spreading its spores.

[@bountywoodsfarm8594]

@@StefanSobkowiak Thanks for your detailed reply! I really appreciate your teaching, as always. The thought just occurred to me- maybe you could add this into the pruning course? Anyway, this will make pruning my plums so much easier!

[@tyramail]

Very informative! Thank you.

[@StefanSobkowiak]

Glad it was helpful!

[@n0sr3t3p]

where should we dispose of these twigs/branches?

[@StefanSobkowiak]

Trash or a hot compost bin.

[@theguineapigchannel]

Can red delicious apple trees get black knot?

[@StefanSobkowiak]

no

[@theguineapigchannel]

Okay thanks!

[@roberthaddad5785]

Thank you

[@perrysplantspoultryandperm6255]

What about a video on irrigation in general? Like how often you turn it on, does it run all day, that sort of thing?

[@StefanSobkowiak]

Yes next season I’ll likely have 3 videos on irrigation system.

[@perrysplantspoultryandperm6255]

@@StefanSobkowiak Wonderful! Love the content and hopefully things open soon because I would love to come check the farm!

[@kahvac]

I'm wondering now what to do with the infected wood ?

[@StefanSobkowiak]

Toss or burn

[@annestudley8235]

How exactly does black knot damage trees? I see it in huge patches in the woods here in Nova Scotia, but those patches don't seem to die out.

[@StefanSobkowiak]

The knot constricts the sap flow to the rest of the branch.

[@annestudley8235]

@@StefanSobkowiakThanks a lot - I guess the forest trees can handle that? I have observe that they can certainly handle inward and crossing/rubbing branches just fine.

[@bountywoodsfarm8594]

Hi Anne, our plum trees had it bad when we came here and it had almost killed them. There were few leaves growing. After doing this procedure for a couple of years (we had to cut them back to mere skeletons) they are beginning to thrive again. I suppose the wild cherries here that have black knot are also somewhat hindered by it, but they do seem to be more tolerant of it.

[@annestudley8235]

Thanks a lot for the story, Stephan.

[@debbieexcell5088]

I learnt a lot.

[@nicoladube3008]

allô j'ai pas compris le nom du produit que tu asperge tes arbres avec, qui compétitionne avec les autres spores. Pourrais-tu me l'écrire merci beaucoup!

[@StefanSobkowiak]

Le lactosérum ou petit lait.