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Acorn harvest at Jaunjelgava oak plantation

Seed harvest is completed at JSC “Latvia’s State Forests” (LVM)’s Jaunjelgava oak seed plantation. The harvested 438 kilograms of oak acorns will be planted in LVM Valmiera arboretum and will turn into 40 to 50 thousand selected oak seedlings.

In Jaunjelgava plantation, which is in an area of 7 hectares and grows more than 600 selected Quercus robur oaks, this is the first significant harvest. Usually, oak trees experience a good harvest once every four to five years. The previous harvest which was also the first one in this plantation was six years ago, when 112 kilograms of oak acorns were harvested.

“This year’s sizeable harvest allowed for acorn harvest straight from the tree, they hadn't even fallen yet. That way we can ensure a larger weight of valuable seeds because the fallen acorns are often harmed. Acorn harvest from the tree is also practically easier because it does not require any additional equipment.

The harvested acorns are initially delivered to the cone dryer where they dry at a specific temperature. Afterward, the acorns are manually checked with hands - the harmed ones are thrown out, while, the valid ones’ “hats” are taken off. Only then are they ready to proceed to the arboretum, where, usually during the same autumn, they are planted in an open field. The oak is ready for sale only when it reaches the age of around 3 years,” Jānis Auziņš, LVM Kalsnava seed production department manager, explains.

The oaks in the Jaunjelgava plantation were selected in Jumprava forest near Skrīveri Dendrological Park more than 20 years ago. Until now, oak seedlings in small quantities were grown in Jelgava and Valmiera arboretum, where acorns were harvested from selected trees growing in the forest. This year’s harvest will provide a selected raw material obtained from a seed extraction plantation with the category “improved”.

The demand for oak seedlings has fluctuated over the years. “LVM Seeds and plants” realized the largest number of oak plants back in 2012 - 134 thousand. In recent years, the demand has been around several thousand.

“LVM Seeds and plants” production manager Laima Zvejniece emphasizes that in the upcoming years, taking into account the increasing proportion of deciduous trees, the demand for oak plants will increase. Some forest owners in Latvia and clients from Estonia have already shown interest in the new oak seedlings.

In the forests managed by LVM, oak trees occupy less than 1% and are mostly planted in special places, for example, in suburban forests or within the framework of specific nature conservation projects. Thus, this spring, several thousand oak trees were planted on the banks of the Tora River in order to purposefully increase the number of deciduous trees in the coastal zone and contribute to better water quality. Over the past four years, the most oak trees were planted in state forests in 2022 – on a total area of ​​14.75 hectares.

Oak is a slow-growing species. The common oak grows very slowly for up to 10 years, then begins to grow at a slightly faster pace. When oak seedlings are planted in a forest under favorable growing conditions, their terminal shoot grows from 50 to 70 centimeters per year. The longest annual shoots of oak are around 60–80 years old, while the largest average growth of oak is at the age of 50–60 years.