雲仙の春。九州山地特有の高山植物ミヤマキリシマは、4月下旬頃から地獄谷付近で咲き始め、徐々に標高の高い場所へ移動します。
池の原（ゴルフ場近く、国の天然記念物）宝原園地は５月初旬、5月３日から６日頃、仁田峠は5月中旬頃が見ごろです。最後に、国見岳の美山霧島の見頃は5月下旬頃です。温暖化のためか、徐々に花々の咲く時節が早くなっています。
ミヤマキリシマは、標高約700メートル以上の雲仙、阿蘇、九重、霧島など九州の高地に群生する植物です。葉や花はヤマツツジに似た小ぶりで、高さは1メートルほどになります。
赤松など周囲の樹木が伸びて日陰になるため、ミヤマキリシマの枝は伸びて枯れやすくなり、被害を受けやすくなります。これを防ぐため、長崎県、地元の有志（雲仙を美しくする会；雲仙住民・ボランティアなど）が毎年恒例のミヤマキリシマ下刈作業を行っています。ミヤマキリシマは江戸時代から島原藩によって大切に守られ、歴史を重ねてきました。

Spring in Unzen. The alpine plant, Miyama Kirishima, unique to the Kyushu mountains, begins to bloom around late April near Jigoku-dani and gradually moves to higher elevations.
Ikenohara-Park(near the golf course, a national natural monument) at Houbara-Park is at its peak around early May, approximately from May 3rd to 6th, and Nita Pass is in full bloom around mid-May. Lastly, the optimum viewing period for Miyama Kirishima on Mt. Kunimi-dake in the beautiful Kirishima mountain range is around late May. Due to global warming, the season for flowers blooming seems to be advancing gradually.
Miyama Kirishima is a plant that thrives in high-altitude areas in Kyushu, such as Unzen, Aso, Kujū, and Kirishima, at elevations of approximately 700 meters or more. Its leaves and flowers are petite, resembling the Mountain Azalea, and it reaches a height of about one meter.
Due to surrounding trees like red pines growing and casting shadows, the branches of Miyama Kirishima tend to elongate and become susceptible to withering, making them prone to damage. To prevent this, the Miyama Kirishima cutting operation has become an annual tradition carried out by volunteers from Nagasaki Prefecture and local enthusiasts, including the Unzen Beautification Society and Unzen residents and volunteers.
Miyama Kirishima has been cherished and protected since the Edo period by the Shimabara Clan, and its history has been preserved throughout the years.