The objective of all forest owners is to grow the best plantations they can and harvest quality timber crops. Getting it right at planting and continuing with a high standard of maintenance in the first four years is a critical step to achieving this objective.

Establishment: pre-planting

Ground preparation and drainage are vital for successful forest establishment. Their main function is to provide an ideal planting environment and encourage strong tree growth.

When a new plantation is being planned, it is important that consideration is given to how the site will be harvested in the years to come.

The choice of ground preparation and location of drains and other site infrastructure can have a substantial positive or negative effect on future harvesting operations. The general site layout and development should both encourage plantation establishment and facilitate the effectiveness of future harvesting operations.

Ground preparation options

Soil type is the most important factor when deciding the method of ground preparation. Inappropriate choice of ground preparation and unnecessary drainage can have cost implications at planting and reduce the efficiency of future harvesting operations.

  • Mechanical mounding: This is the most popular form of ground preparation on poorly draining heavy mineral and peat sites. It involves an excavator digging drains at regular intervals and heaping the soil in mounds. The trees are then planted into the mounds which provides an elevated vegetation-free zone.
  • Ripping: This is primarily used on more fertile mineral soil sites, where drainage is impeded by a compacted layer, such as an iron pan or cultivation pan, beneath the surface. A bulldozer pulls a tine behind it to a depth of 45cm, shattering the pan layer. The trees are planted approximately 10cm from the centre of the rip channel.
  • Planting machine: Only suitable for good soils that do not need cultivation and/or drainage. The plants are placed into a trench opened by a tractor-mounted plough. This system may be used for planting conifers or broadleaves and generally results in very high survival rates and good subsequent growth.
  • Fencing: All grant-aided plantations must be stock proof and the erection of a stock-proof fence may be required. All fencing materials, including posts and wire, must meet the standards required by the Forest Service. Where there is a serious risk of deer damage to broadleaf trees, additional funding may be available for the erection of a deer-proof fence.

    • Planting

  • Plant quality: Trees should only be bought from a reputable forest nursery and should be ordered, where possible, well in advance of planting. The trees should have a strong fibrous root and a straight stem and meet the size specifications as described in the afforestation grant approval.
  • Plant handling: Good plant handling is as important as plant quality. The bags of trees should be handled carefully and, ideally, the trees should be planted immediately. If stored, the bags should be kept upright in a shaded place or shed and planted as soon as possible.
  • Planting trees: Trees must be planted with care to provide the best conditions for successful establishment. The principles of good planting are:

    • • Ensure the tree is planted upright.

    • Plant tree to the correct depth.

    • Place roots into the soil by hand.

    • Cover roots with soil and firm in.

  • Planting season: Normally runs from November to May when trees are dormant and can be safely planted as bare-rooted trees. The planting season can be extended by using plants from cold storage.

    • Fertilizer

    On many planting sites, fertilizer is necessary to promote early tree growth. Phosphorus is the most commonly applied fertilizer on newly planted trees, usually in the form of ground rock phosphate. Fertilizer must be applied between April and August. This is to maximise fertilizer uptake and minimise the risk of environmental damage.

    Plantation maintenance

    The good work at planting stage must be continued into the maintenance of the plantation over the next four years to achieve successful establishment and maximise young crop development.

    If a plantation is not well maintained by year four, future tree quality and timber revenue is likely to be compromised. In some situations, owners can be penalised by delayed afforestation grant and forestry premium payments and additional maintenance costs.

    The most critical areas of maintenance are vegetation control, tree stocking and tree nutrition.

  • Vegetation control: Competition from grass and weeds is the biggest challenge for small trees and effective control is crucial on most forest sites. By year four, trees should be free-growing and growing clear of vegetation competition.

    • Chemical control using herbicides is the most common and cost-effective method utilised. Chemical control is often used in combination with manual grass cleaning, which can be particularly effective against overhanging vegetation after the growing season.

  • Tree stocking: Tree mortalities can occur in young plantations and it is important that the trees are replaced or “beaten up” as early as possible. By year four, at least 90% of the trees should be established. Ideally, tree stocking should be maintained as close to 100% to optimise future tree selection and quality timber production.
  • Tree nutrition and protection: At year four, most trees will have a healthy appearance in terms of colour and vigour. However, on less fertile sites, some trees can show signs sign of ill health which may be due to low soil nutrients such as nitrogen, phosphorous and potassium. If a nutrient deficiency is identified as the cause, this situation has to be corrected and tree growth must respond before application for the second installment of the afforestation grant.

    • During the first four years, young plantations can also experience damage due to frost and animal browsing. Trees can recover strongly from this damage but where there are severely damaged or dead trees, remedial works are required.

    On vulnerable sites, the clearance of vegetation growing on firebreaks is essential to maintain their effectiveness against fire.

    Getting it right

    Successful establishment is the key to a bright future for young plantations. Getting it right first time will save the owners time and money, not to mention headaches, and give their trees the best start on the road to becoming a healthy and productive timber crop. For further information and downloads on a range of forest establishment and management topics, please see www.teagasc.ie/forestry