Seamus O'Brien

Deepest condolences to Seamus's mother Mary, his brothers and sisters and extended family on Seamus's untimely passing.
Truely a great in the world of Irish horticulture and always with a genuine interest in people.
Will be missed in many ways
Ní bheidh a leithéid ann arís

Deep peace of the mighty mountains to you,
Deep peace of the haunting prayer flags to you,
Deep peace of the spirit of Kilmacurrah to you,
Deep peace as you tend the heavenly gardens,
Deep peace dear Seamus to you and your beloved family.

How much I shall miss your knowledge, sparkling wit, and the charming lilt of your voice.

I am so shocked to hear of Seamus's untimley passing just now listening to RTE radio one's Playback as they played a little tribute to him from a recording about the trees in Kilmacurragh Gardens . I got to know Seamus in the late 80 ' when I worked in Arboretum Garden Centre and he was at the start of his horticultural career. He was always such a lovely person when he came in to browse and his passion for plants was so evident. I'll fondly remember his warm smile and friendly chats .
Sending my sincere condolences to his dear Mam and siblings and his many friends and colleagues.
May he rest peacefully.

We were terribly shocked and saddened to hear of the untimely passing of this great man, and our thoughts and heartfelt sympathy go out to all his family and friends. I am genuinely thankful we got to meet him at the RGS, when he gave a most passionate lecture about my grandfather, Frank Kingdon-Ward. Seamus was delighted we were there and invited us over to County Wicklow so I could learn more about my grandfather's exploits. It was deeply sad to learn that Seamus passed away just a month later, but what a legacy. I hope the family know just how much he was loved by countless individuals and organisations, and that they find some comfort in the plethora of messages left by so many at such a difficult time.

Sincere sympathy to all of the O'Brien family on the passing of Seamus, he was a wonderful person. There is a lovely tribute article to him in the Irish Times of Saturday 17th January 2026. May he rest in peace.

Deepest sympathies to all the O'Brien family on Seamus' passing. May he Rest in Peace. Sorry I couldn't make it.

Sincere condolences to Madie and the O'Brien and Wilson families on the sad passing of Seamus. Ar dheis Dé go raibh a anam dílis

Our condolences to the O'Brien family for such a sudden loss of someone in the prime of their life. It was a privilege to have known Seamus. His passion and knowledge of plants, people and history was infectious and outstanding, and it was always a pleasure to be in his company, especially when visiting Kilmacurragh and other gardens. His loss is felt by so many people around the world, but his warmth will be remembered, and his remarkable achievements at Kilmacurragh and his scholarly writings will live on.

Seamus was one of the world's outstanding horticulturists, and I have enjoyed knowing him through his postings on Facebook.My deepest sympathies to his friends and family.

Condolences to Seamus Mother & family.

Seamus was a pleasure to know and so helpful to me when I started work in Fernhill Park and Gardens. He gave up his time and knowledge so freely. Such a gentleman.

He will be sadly missed by all.

We have lost a national treasure, a superb plantsman, a great friend and a man of deep knowledge, integrity and passion. Seamus thank you for all you shared with us, the chats, the laughs and the shared wisdom and gardening advice. We will miss you terribly and I am devastated that you won't get to see the restoration of the house in your beloved Kilmacurragh. Rest gently knowing that your work here will be treasured and honoured and associated with this great garden, plant collection and its garden history forever. I'm so honoured to have known you, shared meals together, botanised together, listened to long eared owls in the darkness, walked the land at Kestrel Ridge with you and to have worked together at Kilmacurragh. The most generous of people with a warm smile, a chat and a never ending fountain of knowledge of plants both in gardens and in their wild places. One of a kind, gone far too young. My deepest sympathies to Seamus's family and all who knew him.

Deepest sympathies to Mary and the O'Brien family and to his many friends on the sad news of the sudden passing of Seamus. Seamus was so knowledgeable, approachable, good-humoured and fun to talk to about plants and his tireless efforts to restore Kilmacurragh. He has left a great legacy in Irish horticulture and the history of Kilmacurragh through his research, explorations and writing but also by so generously sharing his knowledge with others. He will be greatly missed by many colleagues and friends. May he Rest in Peace in the garden of paradise.

My sincere condolences to Seamus' family and friends.
Seamus was a true gentleman and a pleasure to deal with. Always so informative and passionate about his work. A great loss.

Our sincere sympathies to the family, friends, and colleagues of Seamus on his sudden passing.

Seamus was a true stalwart and gentleman of Irish horticulture and a generous, inspiring presence at Kilmacurragh. We will deeply miss botanising with him, where his knowledge, influence, and storytelling enriched us and our students alike. His legacy will live on through Kilmacurragh and in every tree and plant he nurtured there.

Valerie Beck & John Smyth

The GLDA wish to express our deep sadness on the sudden passing of Seamus. GLDA were really looking forward to hearing Seamus deliver his Talk at our Seminar in February and his presence will be truly missed on the day.
From GLDA Council and Members

Deepest sympathy to Mary and the extended O’Brien family on the passing of Seamus. You can be so proud of his great work. May he rest in peace.

Our sincere condolences to Seamus' mother and family.

It was always lovely to have Seamus’ speak at our annual Carlow garden festival talks.Seamus’s passion and remarkable knowledge of plants set him apart. A true gentleman, he will be missed by many.

Rip Seamus

Mary,condolences to you and your family on the very sad passing of Seamus.Rest In Peace.

My prayerful sympathy to you Mary and all the family on the untimely and sudden death of Seamus.i I regret I was not able to attend the funeral. I pray you Mary a deep inner strength and the gentle healing with time . Seamus

Heartfelt condolences to the O'Brien family & extended families at this very sad time.

Sincere condolences to Seamus' family and friends.
I knew Seamus from our time in Multyfarnham when we were all starting out in horticulture. Seamus certainly left his mark and will be missed.

Deepest condolences to all the O'Brien and Harkin family on the passing of Seamus. May he rest in peace.

Seamus was in my class in the Botanic Gardens 1993... l was just thinking about him a few days ago as l was reading one of his books, how I would love to see him after all those years. And today i found out he has passed away.... l am so sorry for your loss, it's just not fair. He was kind, and funny and loved by everyone . R.l.P, Mary.

Sincere condolences to the family on this terrible loss. Seamus was always a pleasure to deal with.

My deepest Sympathy to Mary and all the O'Brien Family on the sad passing of Seamus .May his gentle soul rest in peace.

So sorry to hear Seamus has passed away.Always lovely to meet Seamus on Garinish Island,an amazing man. May Seamus rest in peace.

Ar dheis Dé go raibh a anam, Seamus is already sorely missed by all his colleagues in the OPW. Heartfelt sympathy to family and friends.

Deepest sympathy to the O’Brien family on the sad passing of Seamus. May his gentle soul rest in peace.

My sincere and deep condolences to Seamus’s mother and family.
I will miss his generous and sparkling personality, as well as his endless and enthusiastic horticultural knowledge. His passing leaves an irreparable gap in Irish culture. But his spirit and legacy live on: we will remember him always. Rest in peace, Seamus.

I had known and admired Seamus for a long time but was still diffident about inviting him here - in his busy life. But this old farmhouse is the same age as Kilmacurragh and I thought he might be interested. What a visit. It was such fun, he saw botanical treasures we didn't know we had. He stayed long over coffee in the kitchen - even though he was leaving for Kenya the next day. Another special memory of his warmth & generosity. This brings my deepest sympathy to his family. RIP Seamus.

Deepest sympathy to Madie and family on the sad passing of Seamus. Thinking of you all at this difficult and sad time.

Deepest sympathy to all the O'Brien family.may Seamus rest in peace .

Condolences to the O'Brien family. Such a shocking loss. It was a pleasure to have known Seamus, to learn from him and to absorb his amazing knowledge and passion for plants and horticulture. The fact that his loss is felt by so many people from around the world is testament to his warm personality and enthusiasm for people and plants. RIP Seamus.

Dear Marie and family
we are so shocked and sad to hear of Seamus sudden passing.
I will always remember his joy for life and great sense of humor.
Remember the day at Filoli gardens he had us all in stitches, especially my mother, when he was talking about the ICA women coming into the botanical gardens and sneaking the plant clipping into their handbags.
He was one in a million and so loved by everyone who knew him
May his gentle soul rest in peace x

Deepest sympathies to the O’Brien and Harkin family.
May Seamus Rest In Peace.

Deepest condolences to all the O’Brien family from Jim Fitzpatrick and family. May Seamus rest in peace.

We are shocked and saddened to learn of Seamus’ passing. He was a great friend to the Irish Chinese Cultural Society over the years. May he rest in peace.

Deepest sympathy to all the O,Brien family. May Seamus rest in peace 🙏

Sincere condolences to Seamus' mother and family circle. What a profound loss you all have suffered, and yet I hope the legacy of his life's work will nurture comfort, knowing that it will continue for generations to come. He was a world renowned plantsman with a wealth of knowledge, which he enthusiastically shared with the many that sought his advice. A truly inspirational horticulturist who will be sadly missed, rest in peace Seamus.

Mary we're so sad to hear of the sudden loss of your dear Seamus. Thinking of you, Matt, Micheál. Marie, Donougha, Shane & Eilish, and keeping you in our prayers. We loved hearing about Seamus' next project & how much enjoyment he brought to your lives.
A beautiful nature-filled goodbye for him yesterday reflected the love that everyone has for your dear son and brother. Hoping you will feel his light & strength during these very difficult times.
Suaimhneas síoraí Seamus

So saddened to hear of Seamus’s passing. This remarkable horticulturalist, plant collector, head gardener, educator and good person was such a brilliant contributor. Always supportive and fun, he will be hugely missed. Thank you Seamus for all you achieved - an international legacy. Rest in peace and condolences to his mother and family. Xxx

Sincere sympathy to the O'Brien family on the sudden and very sad passing of Seamus.RIP.

My deepest sympathy to the family and close friends of Seamus.
I studied with Seamus in Multyfarnham. The gentlest and kindest person, but also a brilliant sense of humour. Even as a teenager, Seamus had an unrivalled knowledge and love for plants, and what an amazing ambassador of horticulture he became!
Love you Seamus.

Condolences to the O Brien family on the passing of Seamus, It was pleasure to have known him. May he rest in peace.

My condolences to Seamus' family and close friends. I was fortunate to meet Seamus last year at Kilmacurragh, I was struck by his passion for the gardens - he knew every stem and brick and was himself part of its history. He was extremely generous with his time that day and the afternoon will stay in my memory.

Sincere condolences to Mary Eilish and O’Brien family on the passing of Seamus. May he rest in peace. My thoughts and prayers are with you all at this difficult time.

We are so sorry to hear the very sad passing of Séamus. Our condolences to the O’Brien and Wilson families.
We are thinking of you all at this sad and difficult time.
May Séamus rest in peace.

Deepest Condolences to All the O’Brien Family on the Passing of Seamus.
May Seamus Rest in Peace.

The first meeting with Seamus when he started 30 years in the garden in Glanleam was an unforgettable experience as was the meeting only six weeks ago at the Royal Geographic Society. Such a passion for plants with such a generous nature were a truly remarkable mix.

My deep condolences to Seamus’s family.

May he rest in peace and rise in glory

It was with great sorrow that we learned of the death of a very dear friend and neighbour. Seamus was an exceptional talent with many gifts which he not only placed on display at Kilmacurragh but also for the good of others, an unusual gift which was always freely given and with a great sense of humour!

Please know that you, the family are very much in our thoughts and prayers at this sad time and may we offer your our deepest sympathy. His legacy will live long after he has gone and be a wonderful example to all of us of just what can be achieved in a life of service to others and the natural world. May he rest in peace.

My condolences to Seamus' family. What a shock, what a loss to the plant world; Seamus will be greatly missed. His generosity with his time and his knowledge benefited so many, his massive enthusiasm for plants of all kinds but particularly woody plants has inspired all who spent time with him. The International Dendrology Society hugely appreciated his hosting us at Kilmacurragh just this summer, as well as on earlier occasions for tours and study days.
RIP Seamus.

Im so very sorry for the loss of Seamushe was such a lovely man. I remember last June talking to him about tree fern in kilmacurragh and he gave me great advice. Such a loss may he rest in peace

Our deepest and sincere condolence to the O' Brien Family on the sad passing of Seamus, May he rest in peace.

My sincere condolences to Seamus’s family. We had known each other through the Woody expert group of the RHS. I shall miss his gentle presence and amazing knowledge. A light has gone out in the world but its glow will remain for a very long time and will live on in the memories of those who knew him, and those yet to discover him through his writings.
RIP Seamus ❤️

RIP Seamus. My condolences to all his family. We did a talk together once at the Bots in Glasnevin, the subject being the restoration of Castlewellan Arboretum. I’ll never forget his sheer passion and enthusiasm for plants! I have both his great books, which I will Cherish.

Hugh

Mary my sincere condolences to you and all the family may seamuse's gentle soul rest in peace in the garden of eden such fond memories picking bluebells on our way home from.school all those years ago my thoughts and prayers are with ye all at this the saddest of times

So saddened to hear of the sudden and unexpected loss of Seamus. To Mary and the whole O’Brien family our prayers are with you as you try to comprehend how someone so full of life can be taken so soon. May he enjoy eternal rest until you all meet again.

Sincere sympathy to Mary and the extended O’Brien family on the very sad passing of Seamus.

My condolences to the O Brien family on Seamus passing. A wonderful plants man. He will be greatly missed. May he RIP.

I offer my sympathy to the O’Brien family on the untimely death of Seamus. He was so generous of spirit and readily gave of his time and expertise to assist with a fundraising event in our parish of Kilbride, Barndarrig & Brittas Bay. He will be sadly missed.