Alnus viridis
Contents
Common Names
Green Alder
Family
Description
A deciduous shrub or small tree with the ability to fix nitrogen, can grow in poor and wet soil, the bark and leaves have medicinal properties.
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File:184 D.jpg bark |
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File:184 F.jpg nut |
| Foliage | deciduous |
| Group | broadleaf |
| Toxic Parts? | no |
| Height | 3 - 10m |
| Crown Diameter | 3m |
| Crown Shape | variable |
| Shade Tree? | no |
| Autumn Colour? | no |
| Age | 50-70 years |
| Time to Maturity | - years |
| Flower Colour | |
| Fruit Colour | |
| Bee Friendly? | - |
Native Areas
Found in the central and southern European Alps growing up to elevations of 1000m/3000ft [1].
Preferred growing conditions
| Soil pH Range | 5 - 7 (acidic - slightly acidic - neutral ) |
| Soil Types | sand, silt, clay, loam, chalk |
| Drainage | well drained and poorly drained |
| Soil Fertility | low |
| Sunshine | part sun |
| Soil Moisture | normal to moist |
| Tolerates Exposure | yes |
| Growth Rate | - fast |
Hardiness
| RHS | USDA | EGF |
| H | 4A | H1 |
How to plant
Water container-grown and rootballed trees well and allow to drain an hour before planting. While it drains dig out an area for the tree that is about 2 to 3 times the diameter of the container or rootball and the same depth as the container or rootball. If the soil is compacted loosen with a fork (this includes the sides of the hole). But beware of having soil that is too loose on the bottom as this will cause the tree to be lower than desired upon watering.
- If container-grown, put the tree on its side and remove the container. Place in the hole and loosen the roots around the edges without breaking up the root ball too much. Check the depth by place a cane or stick across the diameter - only the root collar should be below and not the main stem.
- If planting a balled and burlapped tree, remove ties or nails from the burlap at the top of the ball and using a knife if necessary, pull the top of the burlap back, so it does not stick out of the hole when the soil is replaced. Synthetic burlap should be completely removed as it will not decompose. Note burlap sticking out of the hole can wick water away from the tree.
- For bareroot trees, feel the moisture of the roots by hand - if dry, dunk them in an bucket of water for 10-15 seconds and replace the packaging (if you are not going to plant at that time). Do not plant too deeply - only plant up to the root collar. i.e. the stem should not be covered in soil. Ensure roots are planted firmly and have good contact with the soil.
Fill in the hole with soil and compost, but do not add less than half of the original soil.
Using the soil, create a water ring around the outer edge of the hole. Not only does this conserve water, but it will also direct moisture to the perimeter roots, encouraging outer growth. Once the tree is established, the water ring may be levelled. Studies show that mulched trees grow faster than those unmulched, so add a 3 inch layer of pinestraw, compost, or pulverized bark over backfilled area.
Only prune lower damaged branches if necessary. Water newly planted trees regularly in their first year. Staking is also important in new trees and in exposed areas - a 1 m stake at 45 degrees crossing the stem at a height of 15 cm can provide good support. Be careful of the binding of the stake to ensure the tree is not strangled. Binding should be checked in the second year, as the stem will thicken.
When to plant
Early to mid-Autumn, for cold, wet sites wait until early to mid-Spring. Container-grown trees can generally be planted all year round except when it is very hot and dry or the ground is frozen.
Tree care
| Hedging Potential | no |
| Balcony/Roof Terrace | yes |
| Indoors | no |
Potential Pests and Diseases
| Pests | |
| Diseases |
Ecology
via Wikipedia: A. viridis has a shallow root system, and is marked not only by vigorous production of stump suckers, but also by root suckers. A. viridis is a light-demanding, fast-growing shrub that grows well on poorer soils. In many areas, it is a highly characteristic colonist of avalanche chutes in mountains, where potentially competing larger trees are killed by regular avalanche damage. A. viridis survives the avalanches through its ability to re-grow from the roots and broken stumps. Unlike some other alders, it does require moist soil, and is a colonist of screes and shallow stony slopes. It also commonly grows on subarctic river gravels, particularly in northern Siberia, Alaska and Canada, occupying areas similarly disrupted by ice floes during spring river ice breakup; in this habitat it commonly occurs mixed with shrubby willows[2].
History and Human Connection
It was introduced into cultivation in 1820 but it has not been widely planted as an ornamental since [1].
Uses
- As an ornamental shrub or small tree
- In the restoration of landscapes due to its ability to enrich the soil with nitrogen
References