Saturday, August 15, 2026

Garden Bloggers' Blooms Day & Foliage Follow-Up August: Welcome Late Summer Blooms!

Welcome!
Welcome to my zone 7b Long Island garden! As summer passes by quickly, the month of August brings both an abundance of heat and blooms. With some days in the 90’s, thunderstorms arrive in the evening hours and bring some needed rain to the garden. Late bloomers such as Crape Myrtle, hydrangea, allium and  balloon flower (to name a few) bring color to the landscape. Join me for a tour of my late summer garden!
Hydrangea 'Firelight Tidbit'
The first stop is along the entry to the backyard as you pass through the gate. This newly transformed garden has stolen my heart as it was once my mom's iris garden which had finally run its course after some forty years. I planted these Hydrangea 'Firelight Tidbit' as a tribute to her and they have grown and become even more beautiful over the past three years. As fall arrives, the once white blooms will take on a pinkish hue.
Hydrangea 'Limelight Prime'
Also in the back portion of the property is another late summer blooming hydrangea, Hydrangea 'Limelight Prime', which brings beautiful white blooms to give contract against the deep green foliage of the Compacta Hinoki Cypress behind it, Mugo Pine to the right and Variegated Weigela 'My Monet' to the left.
Patio Surround
Along the patio border is Trombly's Red Sentinel Japanese Maple, Ableia 'Kaliedoscope' (blooms late August-September), Spirea 'Candy Corn', Echinacea and a rarely seen variety of Balloon Flower known as Platycodon grandiflorus 'Komachi' whose flowers never open up, but rather remain as uninflated puffed up balloons!
Platycodon 'Komachi' (Balloon Flower)
Here are the blooms up close, and yes...it lives up to its name!
Crape Myrtle 'Sioux'
On an island bed on the southern side of the property is Crape Myrtle 'Sioux', which started blooming about two weeks earlier this year, along with Compact Hinoki Cypress (to the left), Mugo Pine (front) and Juniperus 'Gold Lace' in the backdrop. The hydrangeas along the fence-line are completing their bloom for the season.
Buddleia 'Pugster Blue'
On the opposite side of the raised island bed is Buddleia 'Pugster Blue', a dwarf non-invasive hybrid of Butterfly Bush with large, deep purple blooms.
Spirea 'Candy Corn' and Echinacea Pow Wow 'Wild Berry'
Bordering the patio is Spirea 'Candy Corn' with a second mini round of blooms and in the foreground is Echinacea. 
Southern Border Garden-Secret Garden
Leaving the southern secret garden presents a different view, from before. Crape Myrtle 'Sioux' can be seen in the distance, with Allium 'Millennium' in the foreground. I love seeing these wonderful lavender blooms in late summer. The bumblebees love them too!
Allium' Millennium'
Here is a close-up of a very happy visitor!
Northern Border
Here along the northern portion of the property is a garden statue of a boy reading a book along with Weeping Blue Atlas Cedar and Heuchera (Coral Bells) 'Caramel'...
Echinacea 'Cheyenne Spirit'

and along the pool border, Echinacea 'Cheyenne Spirit' continues to bloom. An American Goldfinch visitor has been enjoying the seeds on a daily basis!
Patio Border
A dwarf form of Sedum growing to only 10-12 inches in height is Sedum 'Pure Joy'. Along the patio, it is starting to show its late summer blooms.

Back Northern Border 
Along the northern fence-line, Kousa Dogwood is joined by Hosta 'Patriot', Rudbeckia 'Little Goldstar',  Gold Lace Juniper (to the right) and Endless Summer Hydrangea to the left.
Rudbeckia 'Little GoldStar' (Dwarf Black Eyed Susan)
I enjoy how this cultivar of Rudbeckia is dwarf, more compact and does not spread everywhere.
Viburnum 'Summer Snowflake'
Summer is winding down, so Viburnum 'Summer Snowflake' is pushing out another round of its white star-like blooms resembling snowflakes...
Pool Border

and the Golden Pacific Juniper which I planted a few years ago seems to be very happy as it trails down the moss rock waterfall. The Juniper is joined by a mature Weeping Norway Spruce and Upright Variegated Boxwood.

Back Shade-Secret Garden
As we approach the end of the tour, a bluestone path leads to the back northern secret shade garden where another Weeping Norway Spruce is joined by 'Caramel' Coral Bells, Pulmonaria, Jacob's Ladder, Cherry Laurel and Variegated Boxwood. At the very end is a miniature bird bath which is visible around the corner bend.
Thanks for Visiting!
I hope you enjoyed your visit to my August garden. I so appreciate you being here, look forward to your comments and enjoy seeing what you have growing in your garden. Special thanks go out to our hostess Carol at May Dreams Gardens, who makes it possible to see blooms on the 15th of every month with her meme Garden Bloggers' Bloom Day. Also, special thanks to Pam Penick at Digging who had hosted Foliage Follow-Up, a meme I will continue to honor. I am also linking with some other wonderful hosts and hostesses at Floral Friday Fotos, Nature Notes at Rambling Woods, and Garden Affair at Jaipur Garden.

Connect With Me
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It's time to plan your garden! Visit my Author Page 👈to learn about and purchase my books, each one focusing on different aspects of gardening, including landscape ideas, design principles, gardening by month for all-season interest, gardening tips and maintenance, shade gardening, gardening inspiration and more. And also be sure to check out my newest publication, The Houseplant Guide, to guide you on your houseplant journey! If you have read any of my books and have found them to be useful, reviews are very much appreciated!

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Until we Meet Again...Happy Gardening!

Saturday, August 1, 2026

Black Knot Disease on Ornamental Plum: Early Signs, Treatment, and Compacted Clay Soil

Black Knot Disease & How to Treat
Welcome to This Month in the Garden. Ornamental plum trees are prized for their beautiful spring blossoms and colorful foliage, making them a favorite in residential landscapes. Unfortunately, these trees are susceptible to Black Knot, a fungal disease that can gradually weaken and disfigure even healthy-looking specimens. While the fungus itself is the direct cause of the disease, environmental stresses, such as compacted clay soil can make ornamental plums much more vulnerable to infection and reduce their ability to recover. I have seen a substantial decline in these beautiful ornamental plum trees over the past few years and am now experiencing the same for my own tree, a valued addition to the landscape which I have enjoyed for many years. Here are some helpful signs to watch for and ways to help.    
Purple Leaf Ornamental Plum (Prunus cerasifera 'Krauter Vesuvius')

What Is Black Knot?: Black Knot is a fungal disease that primarily affects trees in the Prunus genus, including ornamental plums, flowering cherries, chokecherries, and some wild plum species. The fungus infects young twigs and branches during cool, wet spring weather, and spores are spread to other trees by rain and wind, entering through tender new growth. Once established, the disease develops slowly, often taking several months before visible symptoms appear. As the disease progresses, these black growths enlarge and may completely encircle branches, restricting the flow of water and nutrients. Severely infected limbs often decline and eventually die.

Warning  Signs: Black Knot disease can be identified by the appearance of small olive-green or light brown swellings on young twigs in springtime, causing slightly enlarged or rough bark. Elongated galls gradually expand during the growing season and form hard, black, corky knots which become more obvious later in the summer or the following year.

Detecting Black Knot Disease

How to Treat Black Knot: Successful treatment requires both pruning and sanitation of tools. If you see the first signs of Black Knot Disease on your tree, immediately remove the branch. Once this is accomplished, the best time to prune is while the tree is dormant and branches are more visible. Remove infected branches during late winter on a dry day before spring growth begins. Prune at least 6–8 inches below the visible knot, and if  the infection is on a large branch, remove the entire branch if possible. After each cut, it is important to disinfect pruning tools with a solution such as 70% isopropyl alcohol. This helps reduce the chance of transferring fungal spores between branches or trees. Dispose of the infected wood and dispose of them with yard waste (where permitted). Black knots left on the ground can continue producing spores that infect other nearby trees.

Fungicide Use: Preventive fungicides can help protect healthy new growth, especially when your tree has had recurring infections. Fungicides are most effective when applied before and during the period of new shoot growth and should be used according to the product label. Fungicides will help to prevent new infections but will not cure existing knots.

Why Compacted Clay Soil Makes the Problem WorseMany ornamental plums are planted in landscapes with heavy clay soils. While clay soils can hold nutrients, they often become highly compacted over time. This compaction reduces oxygen flow to the roots; hence, stressing the tree and leaving it open to disease. Poor drainage caused by the heavy clay soil can encourage root rot and eventual decline of the tree. When a tree is under stress, it has difficulty producing healthy new growth. While compacted soil does not cause Black Knot Disease directly, it can make ornamental plums more susceptible and slow recovery after pruning.

Identifying Compacted Clay Soil
Correcting Compacted Clay SoilTo correct compacted soil, apply organic mulch. Spread 2–3 inches of shredded bark or wood chips beneath the tree, extending as close to the drip line as practical. Keep mulch several inches away from the trunk to prevent moisture buildup against the bark. Another tip to help with amending the soil is to incorporate compost into surrounding planting beds or top-dress annually. As organic matter breaks down, it improves soil structure, increases pore space, and encourages beneficial soil organisms. If you detect Black Knot Disease and the soil is compacted clay, use a post  hole digger and create several 2-3 foot deep holes around the base of the tree and fill with gravel to help improve drainage. Be careful not to disturb the roots.

Can an Infected Tree Recover? Trees with numerous large knots throughout the canopy may continue to decline despite treatment. In severe cases, removal and replacement may be the most practical long-term solution, particularly if nearby susceptible trees are at risk. When caught in time, many ornamental plums have recovered from Black Knot if the disease is detected early, infected branches are removed promptly, and the tree's growing conditions are improved.

Ornamental Plum
In Conclusion: Black Knot is a serious but manageable disease of ornamental plum trees. Early detection, careful pruning, and good sanitation are essential for stopping its spread. Addressing compacted clay soil by improving aeration, adding organic matter, and protecting the root zone helps reduce stress and supports the tree's natural defenses. Healthy trees are never completely immune to disease, but they are far better equipped to withstand infection, recover from pruning, and continue providing years of beautiful spring flowers and colorful foliage with the proper monitoring and care.

Author: Lee Miller @A Guide to Northeastern Gardening, © Copyright 2010-2026. All rights reserved.