Giants Grove Managing Expectations

Written by Sean

September 29, 2022

The Giants Grove is a forest like few others, for many reasons. It is the largest Redwood forest outside of its native California, a gene-pool to protect the Redwood species from climate change, a symbol of the Irish diaspora, and a continuous-cover eco-forest that will take 1200 years to mature. However, what makes the Giants Grove truly unique are the Sponsors, and their dedications. Every tree has a story, a reason, a purpose, – every tree is more than just a tree, it is a memory.

As a Forester, it is unusual for me to focus on individual trees. Birr Castle Forest Estate alone has over 400 Hectares of woodlands, more than a million trees to look after, and not many are unusual, much less have a story. However, since it was established, I have gotten to know the Giants of the Giants Grove, the names of the Sponsors, the history behind them, and how important they are. Every tree is special, every tree must be perfect, and that is what makes managing the area so different, so difficult, when the trees experience issues. Every young forest has its own problems. The Grove is doing well, but this Newsletter today is about drawing attention to, and being realistic about, some of the difficulties we have had in the past, the present, and those we can expect in the future.

Transplant Shock/Replacement

Most forestry trees are grown in a nursery for 2 to 3 years and are then transplanted into their new site. This stresses the young saplings, although most survive the move. Unfortunately, generally 10-15% suffer transplant shock and die. The older the transplant, the greater the mortality rate. This is common, and the dead trees are usually replaced the following year by ‘filling-in’ or ‘beating-up’. The replaced trees soon catch up to their neighbours, being drawn upwards by their competition, and before long there is no noticeable difference between the new and the older. This has happened to some of the sponsored Giants, but all were replaced as soon as possible. Recently, some trees were ring-barked and killed by a rogue deer and rabbits, and they were also replaced.


It is standard practice to use powerful chemical herbicides to treat weed competition in young forestry plantations, to get the plantations established quickly. We are different. We do not, never have, never will. Most herbicides can be harmful to humans and animals, cause non-selective vegetation removal, are persistent in the soil, and can ‘run-off’ into waterways. Redwoods take 1200 years to mature, so we are not in that much of a hurry to get them established anyway. However, weed competition can be a significant problem, and we have to grass-clean the trees manually at least twice a year to ensure they are not smothered. This ‘no chemical approach’ is the policy at the Giants Grove, and it was decided upon very early in the project planning. Some visitors are surprised, some are even shocked, by the wildness of the site, but a real forest has many levels, and even the ugliest weed is an important home to more than a few species of insect, spider, bird, and mammal.


One of the ways I know I am getting old is the fact that I know the weather these days is different to when I was younger. The weather in Ireland was always reliable – it was usually wet, but always reliable. Recently, most likely due to climate change, we have been experiencing extreme weather, instead of the mild weather we are used to. Since its planting, our Redwoods have endured two unusual droughts, one unusually bad flood, and this year we had a late frost in May, very unusual. We cannot do much about the weather, but we have watered trees, replaced trees that died due to drought, and pruned those effected by the frost. However, soon the Redwoods will be too tall to be touched by frosts, too strong to be affected by flooding, and have roots too deep to be bothered by drought.

Deer Damage

There is no doubt that deer are a beautiful, majestic, animal, an intrinsic part of any woodland we might dream of, but they are a nightmare in young, establishing, forests. They can uproot newly planted trees, browse the shoots and buds, and strip bark from trunks and branches through fraying. A small population of deer is welcome in the Giants Grove, and was expected – one reason for the nurse trees was to attract the deer away from the Redwoods. This year a large male was in the vicinity, and caused some damage, ring-barking several Redwoods while rubbing the velvet from its antlers.

Rabbit/Hare Damage

Either rabbits or hares, or both, are also new visitors to the Giants Grove, and have caused some damage. The damage they cause is very similar to each other’s, and difficult to blame on one or the other. They strip the bark, like deer, but closer to the ground. Again, several Giants were damaged, and so we protected all the Redwoods with tree-guards. I believe the damage, and the new animal visitors, are a direct result of the ‘wilding’ of the site – it was once busy, managed, farmland, and now it is a quiet reserve, where woodland wildlife feel safe, and have plentiful food. As the Redwoods grow, their bark will soon be too thick to be harmed by bunnies, and unfortunately, a large amount of wildlife will eventually attract a fox or two which will control numbers naturally.


Completely unexpected, and totally unforeseen, the management of the Sponsor labels has been one of the greatest challenges at the Giants Grove. It was difficult to find a sustainable label that could withstand weathering, and was not irresistible to nibbling deer, but we managed it. The real problem has been labels mysteriously moving from one tree to another. Now, I’ve been a Forester for over 20 years, and have seen many forests grow and mature , and I can guarantee that there is no way anyone could select which young tree, out of hundreds, would out-perform another, and be the ‘better’ tree at maturity. Tall saplings, that tower over their neighbours now, may have underdeveloped roots which would cause instability as it matures. Or a small sapling, suffering a little now from flooding, may thrive on that extra moisture when it needs 10 gallons per day at maturity. And Redwoods are apically dominant, so that crooked sapling will shoot straight upwards once the canopy closes. Remember, we are 3 years into a 1200-year project, and it is far too early, probably a couple of hundred years too early, to choose a champion yet. If anyone is unhappy with their tree, or its position, just let us know, and we will do our best to accommodate you. But my advice is to be patient, your tree will surprise you.


Perhaps the most difficult challenge in managing the Giants Grove is managing people’s expectations. The name conjures up images of massive trees, impressive heights, and inspiring girths – a grove of giant trees. It will be all those things, but not for decades. Every iconic Redwood in their true home, Sequoia National Park, California, began as a little sapling like those in the giants Grove. They suffered drought, fire, deer, and frost, but they have seen and survived it all. The world’s tallest tree, the Coastal Redwood Hyperion, is 115 meters tall. General Sherman, a Giant Redwood and the world’s biggest tree, is 1,490 cubic meters in volume. We will never know what they looked like as saplings, but maybe they looked just like your tree in the giants Grove.

The Giants Grove Project is an Partnership between Birr Castle Estate and Crann – Trees for Ireland

Sean McGinnis Ecoplan Forestry

Tags: Birr CastlecrannEcoplanGiants GroveGiantsGroveredwoodssequoia

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