Metla Project 3257

Summer planting of the container seedlings

[  Suomeksi  |  Objectives  |  Results  |  Project leader  |  Researchers  |  Publications  |  Media releases  |  Metla Research  ]

Duration: 1999-2003   Keywords: Norway spruce, drought tolerance, planting date, root egress, short day treatment, silver birch, stress resistance


The aim of the project was to find out the alternatives to production and planting chains of Norway spruce and silver birch so that the planting of container seedlings is possible from spring to autumn. During the project field performance of seedlings planted in different dates during growing season and factors affecting it was clarified. The objective was to find out the best seedling material and nursery production methods for each planting date.

For find out the best possible chains the following questions were studied
  1. field performance and root egress of seedlings planted on optimal and harsh environmental conditions in different dates
  2. planting date and risk for frost damage of frozen stored seedlings planted at dormant
  3. stress (drought, mechanical) resistance of actively growing seedlings
  4. production method of seedlings grown for different planting dates
  5. susceptibility of actively growing Norway spruce seedlings on insecticides against large pine weevil
  6. field performance of practical scale mechanical and manual planting


Tree seedlings are conventionally planted during short period in May and in some extent in early autumn. This causes problems both in nurseries and plantings. In addition, number of workers doing silvicultural works has been decreased during the last decade. One solution is mechanized planting. To increasing the productivity of mechanized planting the planting period of seedlings have to be as long as possible. To enlarge of planting window from spring to whole growing season will give some advantage also to manual planting chain.


When silver birch container seedlings were planted as actively growing and leaf-bearing from mid-June to mid-August, their growth was increased after the planting compared to seedlings planted in spring or autumn. Root egress of seedlings was rapid after the planting, which increased the growth of seedlings the following years. Seedlings planted in summer performed well if they were protected against wind during transportation and not stored longer than 1-2 days in field storage and well-watered at the time of planting. After the long drought periods short, leaf-bearing silver birch container seedlings can not be planted.

First results from coniferous seedlings showed that survival of growing, well-watered seedlings planted in June and July was not decreased compared to seedlings planted as dormant in spring. Frozen-stored seedlings can be planted until mid-June, after that their risk to damage in first autumn frost is increased.

Project leader: Luoranen, Jaana
The Finnish Forest Research Institute, Suonenjoki Office, Juntintie 154, FI-77600 SUONENJOKI, FINLAND
Phone: +358 29 532 4869

Other researchers: Helenius, Pekka, SU (1999-2000), Rikala, Risto, SU (1999-2000), Smolander, Heikki, SU (1999-2004), Zhang, Gang (2001-03)

Top of page

Updated 12.06.2012