For our Irish climate, the Birch trees that are most comfortable here are the beautiful eye pleasing Silver Birches, also known as Paper Birch. I say "eye pleasing" due to its striking smoothish white papery bark that shines in the sun plus its distinct black fissures. The more matted greyish bark Downy Birch. also known as the White Birch, despite being more native to colder climates, does actually grow well in Ireland.
I believe the Downy Birch would be more active at creating new native woodlands on moist lowland barren moorland.
preferred soil conditions
Birch can grow comfortably in the poorest of soils, hence why is is a colonizing tree. Just as it's mythology tells, Birch the first life on earth and it is also usually the first tree to create a forest.
To encourage the growing of the healthiest Birch trees a constant cool moist soil is best, but not too waterlogged, and definitely never dry.
Birch should receive a good watering during dry spells. In the woodland their moistness is protected by the debris of fallen leaves and branches. In our home gardens we can provide the same care by keeping their base soil well mulched at all times.
There is a growing interest in growing more native trees along and beside waterways in Ireland. Species of Willow and Alder are very natural for this, but Birch trees are being added with an intent of beauty, but also they would do very well there by the waterside accompanies by Alders, Willows and other native trees that may also find their way to join them.
preferred light, shade and water conditions
Birch trees need light. In a native environment as Birch is said to be the first tree to colonize some land to attract a woodland creating it will enjoy its own exclusive full light for awhile. As more trees surround a Birch the leaves become smaller and wider apart. Once a forest is established the Birch trees will fade away, except for those that have the honour of being at the light edges of a forest.
budding
From early January, reddish purple buds usually start developing quickly. These buds burst into leaves through early April. Birch tress are often the first of the broadleaved hardwoods to break into leaves, each Spring.
blossoming
Green catkins also form on Birch trees from around mid January, sometimes earlier. These beautiful catkins then become yellow with abundant pollen during late March, just before the Birch trees leaves open in early April.
fruit and seeds
The fruit of Birch trees are called "samaras". They are single seeds enclosed within a dry skin and have wings attached to these small seeds. These winged seeds are produced from the catkins. When they hang from the catkins, while forming, they look like turkey feet. Once released from the tree, these winged samaras can be caught in the wind and travel quite far. Maybe one or two of these flying Birch seeds are pioneers of future forests, if we allow this :-)
These Birch seeds fall from the trees and catch the wind any time through the summer or autumn.
coppicing?
Birch is no longer a popular wood for coppicing due to limited uses of its coppiced branches compared to other broadleaved hardwoods.
Birch was grown to coppice to make 'faggot' bundles of sticks and narrow poles tied together. 'Faggots' were used to prop up stream and canal banks to stop bank erosion, to make the walls for raised garden bed and used as a fuel too. Of course, these uses could be revived and be very useful today.
There are some enthusiasts who still coppice Birch, and it may become a future revival. The branches and trunks can be coppiced every four years for wood supplies for poles and the thin sticks used for besom and broom making.
Birch trees are quite famous for their association and relationship with fungi. Fungi that forms relationships with trees are called mycorhizae. The fungi that support Birch trees include the famous fly agaric toadstools that are associated with gnomes, fairies, Vikings and Alice In Wonderland.
Also supported by Birch are milk-cap fungi and the brown birch bolete, which is a toadstool species without gills but hosts a kind of sponge instead.
Mycorhizae are fungi that form a massive network of fine threads through the soil that absorb minerals from the soil and transports these minerals to their host tree in exchange for extracting sugars from the tree. Tree sugars are formed from a synthesis of carbon dioxide from air and light.
I speak of the mythology of Birch being the first life on earth, but the birch and fungus partnership is very essential as a basis of much of our ecosystem. Birch trees can grow very badly without their fungi partners nearby creating a state that botanists call "mutual symbiosis". Some say that the fungi, especially the fly agaric, was the first life on this earth. We are also aware that fly agaric toadstools could not grow and survive alone, so they were gifted the birth of the Birch tree.
What a wonderful illustration of how everything is connected in nature. A very simple but profound example of what biodiversity and permaculture are about.
Many moth species are also supported by birch trees. They eat the leaves, but unfortunately do not give anything back.
Finches, woodpeckers and squirrels love to eat Birch seeds and also help to scatter them, an addition distribution to the wind.
to read about the healing and nourishment qualities of Birch, please click here