Tree Planting & Maintenance

Preparing to plant

Optimising the timing of tree planting - The optimal time for planting trees depends on soil water availability. In areas that have a seasonal climate, trees should be planted early in the rainy season, once rainfall has become regular and reliable. This gives the trees the maximum time to grow a root system that penetrates deep into the soil, allowing them to obtain sufficient water to survive the first dry season after planting.

Preparing the restoration site - Protect any existing, naturally established trees, seedlings, saplings or live tree stumps, taking care not to miss smaller tree seedlings that might be obscured by weeds. Place a brightly coloured bamboo pole next to each plant and use a hoe to dig out weeds from a circle of 1.5 m in diameter around each plant. This makes the natural sources of forest regeneration more visible to workers, so that they avoid damaging them during weeding or tree planting. About 1–2 weeks before the planting date, clear the entire site of herbaceous weeds (either removing weed roots or herbicide use) so as to improve access and to reduce competition between weeds and trees (both planted and natural).

How many saplings should be brought in? - Density of planted and naturally established trees should be about 3,100 per ha, results in an average spacing of about 1.8 m between planted saplings or the same distance between planted saplings and naturally established trees (or live stumps) because the objective is rapid canopy closure that will shade out weeds and eliminate weeding costs.

How many tree species should be planted? - For a plot with stage-3 degradation, count how many tree species are well represented by the sources of natural regeneration recorded in the site survey (see Section 3.2) and deliver enough species to top up that number to at least 30 or around 10% of the estimated species richness (if known) of the target forest type . For a plot with stage-4 degradation, plant as many species of the target forest type as possible.

Transporting saplings - Saplings are very vulnerable, particularly to wind and sun exposure. Select the most vigorous saplings in the nursery after grading and hardening-off. Label the saplings that you intend to include in your monitoring program, then water just before loading them into the vehicle, and transport them to the planting plot the day before planting.

Planting materials and equipment - The day before planting, transport planting materials to the plots along with the saplings. These include a bamboo stake and mulching material (if required) for each sapling as well as fertiliser. Protect these materials from rain by covering them with a tarpaulin.

1. Knife
2. Gloves
3. Fertiliser, bucket and premeasured cups
4. Baskets for saplings distribution
5. Hoes for hole digging
6. Mulch mats
7. First-aid kit
8. Bamboo poles

Planting

Spacing distances

Mark where each tree will be planted with a 50-cm split-bamboo pole. Space the poles at 1.8 m apart or the same distance away from naturally established trees or tree stumps. Try not to position the stakes in straight rows. A random arrangement will give a more natural structure to the restored forest. Staking out the plots can be done either on planting day or a few days in advance.

Planting method

1. Use baskets to distribute one sapling to each of the poles. Mix up the species so that saplings of the same  species are not planted next to each other. This ‘random’ planting is known as an ‘intimate mix’.
2. Dig a hole that is at least twice the volume of the sapling’s container, breaking up the soil around the root system will also help the roots to establish. At the same time, use the hoe to drag away dead weeds in a circle of 50–100 cm in diameter around the hole.
3. If the saplings are in plastic bags, slash each bag up one side with a sharp blade, taking care not to damage the root ball inside, try to keep the medium around the root ball intact.
4. Place the sapling upright in the hole and pack the space around the root ball with loose soil, making sure that the sapling’s root collar is positioned level with the soil surface. If the sapling has been labelled for monitoring, make sure that the label does not become buried.
5. Apply 50–100 g of fertiliser in a ring on the soil surface about 10–20 cm away from the sapling stem. Chemical burning can occur if fertiliser contacts the stem itself.
6. (Optionally) place a cardboard mulch mat of 40–50 cm in diameter around each planted sapling. Anchor its position by piercing with the bamboo stake and pile dead weeds onto the cardboard mulch mat. It reduce the risk of drying out and weed growth.
7. The final task is to remove all plastic bags, spare poles or cardboard mulch mats, and garbage from the site.

Caring for planted trees

In deforested sites, planted trees are subjected to hot, dry, sunny conditions as well as to competition from fast-growing weeds. Protective measures must be implemented to prevent fire and cattle from killing both planted trees and any natural regenerants that are present. Weeding and fertiliser application are also essential for at least 18–24 months after planting in order to maximise tree growth and accelerate canopy closure. No further maintenance is necessary after canopy closure.

Weeding

- Ring weeding : Remove all weeds, including their roots, using hand tools within a circle of 50 cm radius around the base of all natural seedlings and saplings.

- Weed pressing : Remove shade by flattening all remaining herbaceous vegetation between the exposed natural regenerants using a wooden board (130 × 15 cm).

Pressing is best carried out when the weeds are about 1 m tall or taller: shorter plants tend to spring back up shortly after pressing. The best time to press grass is usually about two months after the rains start when grass stems easily fold.

Fertiliser application

Most tree seedlings and saplings of up to about 1.5 m tall will respond well to fertiliser applications during the first two years after planting, regardless of the soil fertility. Fertiliser application both increases survival and accelerates growth and crown development. It enables the trees to grow above the weeds rapidly and to shade them out, thus reducing weeding costs.

Apply 50–100 g fertiliser, at 4–6-week intervals, immediately after weeding, in a ring about 20 cm away from the tree stem. If a cardboard mulch mat has been laid, apply the fertiliser around the edge of the mulch mat. Chemical fertiliser (N:P:K 15:15:15) is recommended for upland sites, whereas organic pellets produce significantly better results on lateritic lowland soils.