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The Pittsburgh Sakura Project (PSP) is an independent nonprofit organization founded in 2008. We plant and maintain 250 ornamental cherry trees and more park trees in Allegheny County's North Park.
The unofficial national flower of Japan, cherry blossoms symbolize many things: delicate beauty and transience, new beginnings, friendship of the US and Japan. Our aim is for lovers of cherry blossoms to enjoy beautiful, mature cherry trees in the Pittsburgh region.
Review the 2025 season with the PSP blossom forecast!
Your may donate here using our secure Clover link.
Announcements:
Bundle up for Winter Tree Care Work Sessions!
Saturdays in February and March, 10 am to ~ noon: 2/21, 2/28, 3/7, 3/14, and 3/21, before the buds begin to open; While the trees are in their winter dormancy, our main work is pruning to control Black Knot fungal infection. For details and to sign up: Volunteer
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Management of Black Knot (Fungal Infection) by Pruning
The main treatment for this disease that impacts stone fruit trees is pruning of infected parts to remove the spore-releasing fungi from the trees.
1. Pruning Period
The ideal time for pruning is while the trees are in their winter dormant state and the spores are least likely to be spread, i.e., mid-November to just before bud-break (mid- to the end of March).
2. Pruning Method
Remove the knot with a cut 6 - 8" away from it, including some healthy tissue.
Because the fungus extends beyond the visible knot into the tree tissue, removing the extra 6-8" of a healthy-looking branch is very important to prevent recurrence.
For knots on large branches near the trunk, use appropriate pruning methods to remove the branch without damaging the branch collar.
3. Disinfecting Equipment
It is extremely important to disinfect the pruniing equipment (e.g., pruners and saws) after EACH cut, so as not to spread spores via the blades.
Examples of Disinfection Methods:
Spray or wipe cutting blades with an alcohol (e.g., isopropyl or ethanol) solution of 70% or more.
Immerse in a 10% Sodium Hypochlorite solution (household bleach diluted with water)--watch out for corrosion of metals.
4. Disposal of infected branches
Burn, or bag and send to a landfill. If you leave infected clippings on the ground they will continue to give off spores which can be dispersed by wind and rain, spreading infection.
Burning is the recommended disposal method, but the Allegheny County Parks Dept. is not allowed to burn, so we collect the clippings in plastic garbage bags and dispose of them.
💊 Prevention and Supplemental Control Measures
1. Fungicidal Treatment
Timing: As a supplement to pruning, fungicidal sprays can prevent trees from becoming infected, or can help them fight a future infection.
But fungicidal treatment does not cure trees that are already infected. It is a preventative treatment.
Fungicidal sprays are generally used in orchards, where trees have commercial value and public access can be controlled.
2. Selection of Resistant Tree Varieties
When planting new trees, choosing resistant varieties is the best preventative measure. We have gotten conflicting recommendations about which varieties are resistant. At present it appears that Sargent and Kwanzan cherries are the most resistant types of ornamental cherries that are suited to conditions in North Park.
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Fall Planting Day!
A hearty THANK YOU to all who joined us on Saturday morning, November 1, to plant 10 cherry trees.
See photos here
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Important Announcement
The cherry trees in North Park currently face a serious problem.
Many of our cherry trees have become infected with a disease called Black Knot (a fungal disease in which black knots form on branches, causing them to eventually die). This problem has been seen in the area for several years, and the Pittsburgh Sakura Project has been following the standard management of removing the knots by pruning in the winter. Despite our efforts, since the spring of 2025, the damage caused by Black Knot has accelerated and spread, made much worse by the high rainfall and humidity.
In June, 2025, the Pittsburgh Sakura Project met with the Allegheny County Parks Dept., North Park Maintenance, and tree care professionals. It seems that the native black cherries growing wild in North Park host the Black Knot fungus. At present, the infection is mainly seen on our Accolade and Autumnalis cherry trees. Little spread has been observed on cherry trees such as Yoshino, Kwanzan, Weeping Cherry, Akebono, and Okame. The Pink Flair and Snowgoose seem fine too, but we remain vigilant.
Allegheny County Park, North Park Maintenance, and the Pittsburgh Sakura Project are working to solve this problem. Pruning of black knots and removal of any trees that are deemed too sick to save will take place in late fall and winter. We have been informed that pruning and cutting cannot be done in spring, summer, and early autumn, while fungal spores are active, due to a high risk of the spores spreading. The other part of the management strategy involves spraying fungicide on the trees from when they start to leaf out until early June. This will be a large, costly process. We will post here when we know more about that.
Please check back here for updates.
We appreciate your continued cooperation.
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Fall tree care was finished as of mid-December. Spring tree care was finished on 5/19/2025. Thanks to the volunteers who have given their time on Sundays, and occasionally Mondays!
See photos of a trial for "Sakura Light-up Nights" (planned for spring of 2026, courtesy of the Allegheny County Parks Dept). The test took place on the night of 4/19/2025. Click the English button at the top of that page to return here. We're already looking forward to next spring!
Updated: 5/25/2025
In Appreciation
The PSP Event Committee would like to thank all the volunteers who contributed to the success of our April 12th Hanami Event: Takumi Kato and his family for the taiko performance; participants in the planting and tree care demonstration; participants in the blossom tours; and the many who helped with registration, photography, refreshments, program, set-up and cleanup.
Updated: 10/2/2025
2025 Hanami (Cherry Blossom Viewing) Event in North Park
2025 Hanami (Cherry Blossom Viewing) Event in North Park
Date and time: Saturday April 12, 2025 2:00to 4:00pm (Rescheduled from April 5)
Date and time: Saturday April 12, 2025 2:00to 4:00pm (Rescheduled from April 5)
Location: North Park, Harmony Shelter (near the Boathouse)
Location: North Park, Harmony Shelter (near the Boathouse)
Participation fee: Free
Participation fee: Free
Activities: Do as you like, enjoy the cherry blossoms. We will provide a cherry blossom site tour, a tree care demonstration, drinks and snacks (while available).
Activities: Do as you like, enjoy the cherry blossoms. We will provide a cherry blossom site tour, a tree care demonstration, drinks and snacks (while available).
Registration: Use this registration form. (Walk-ins are also welcome, but we'd like to have an idea of how many people to expect.)
Registration: Use this registration form. (Walk-ins are also welcome, but we'd like to have an idea of how many people to expect.)
The Pittsburgh Sakura Project assumes no legal or financial liability for accidents or injuries during and after this event.
Any updated information will also be provided through the Pittsburgh Sakura Project Google Group, so if you are interested, we recommend that you subscribe.
Any updated information will also be provided through the Pittsburgh Sakura Project Google Group, so if you are interested, we recommend that you subscribe.
Latest news
The flowering schedule is..
Includes Upcoming Tree Care work sessions
Older Announcements
We provide cherry blossom forecasts and information.
To receive information, subscribe to the Pittsburgh Sakura Project Google Group, and/or follow us on Facebook
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See more photos on Instagram!
Events Calendar
Latest Update: North Park is covered in snow, but the cherry blossoms are preparing to bloom in spring January 21, 2025
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