Willow (Crack)
General characteristics of a Willow (Crack)
The Crack willow (Salix fragilis), also known as Brittle willow, is a tree in the willow family (Salicaceae). The crack willow is quite rare in the Netherlands. It owes its name to its branches, which break and split easily, producing a cracking sound. The crack willow can grow up to 25 m tall, making it one of the largest willow trees. The crack willow is a narrow-leaved willow with finely serrated, fairly narrow leaves. However, identification is not easy because there are many hybrids with the crack willow. This hybrid, Salix x rubens, is much more common than pure crack willows.
The crack willow has catkins. Male catkins are yellow and 2-2.5 cm long. Female catkins are up to 10 cm long, initially green and later white. They contain seeds with a tuft. Flowers are contained within the catkins. They emerge with the leaves and are slender, cylindrical, and pointed.
Characteristics
How to plant a Willow (Crack)
Plant as deeply as possible, 40-60 cm into the soil, preferably until ground water level, ideally from mid-February to the end of March. There is less chance of success in November or December.
How to harvest a Willow (Crack)
Saw off twigs of existing shrubs with a slanted point for planting.
Caring for and pruning your Willow (Crack)
Crack willow, known for its fragile branches, benefits from pruning in early spring. Focus on removing dead, damaged, or crossing branches to promote structural integrity and air circulation. Prune young specimens to shape them and mature ones to maintain size and health. Regular pruning reduces the risk of branch breakage and encourages robust growth. Proper pruning promotes the overall vitality and appearance of the crack willow.
It prefers constant moisture and should be watered every three weeks to maintain hydration without saturating the soil.
Where does a Willow (Crack) grow
Crack willow is a riverbank tree par excellence. The ease with which its twigs break promotes vegetative dispersal along the river. The tree tolerates daily flooding. It is not particularly picky about soil, although its most natural, alluvial habitat is normally clayey. However, in the old agricultural landscape, planted trees are found on most other soil textures. Incidentally, the species often grows much drier there than in natural conditions.
General
| Origin |
Native
|
| Tree Type | Deciduous tree |
Length and Age
| Length in about 10 years | 5 Up to 12 Meter |
| Reproductive Maturity in How Many Years | 4 Up to 20 year |
| Maximum Age | 20 Up to 30 year |
| Required Space | Up to m2 |
| Growth Rate |
Reproduction
| Tree is Self-Pollinating | No |
| Reproduction Method |
To cut (cutting is between 5 and 50 cm)
To be pollarded (the slit is approximately 2m)
Makes seedlings
|
| Reproduction rate |
|
Reproduction rate
| 1. Very low reproduction rate. The plant hardly spreads, has few seeds or vegetative spread (e.g., trees with heavy seeds). |
| 2. Low reproduction rate. Spread via limited seed production or specific conditions required |
| 3. Average reproduction rate. Regular spread, depending on wind, water, or animals, at a moderate speed (e.g., dandelion). |
| 4. High reproduction rate. Many seeds and multiple spread strategies (wind, birds, vegetative). Quickly colonizes open spaces |
| 5. Very high reproduction rate. Invasive species that spread explosively over large distances (e.g., Japanese knotweed). |
Pruning Period
| This Tree is Evergreen | No |
| Summer | No pruning in summer |
| Winter | November tot March |
| Leaf Shapes | Lanceolate |
| Easy to prune | Yes |
Bark Characteristics Seedling (50-200cm)
| Lenticels | Yes |
| Colour |
Bud Characteristics Seedling (50-200cm)
| Colour | |
| Bud Position |
Varied
|
| Bud Shape |
Pointed
|
Other
| Root |
Superficial rooting
Deeply rooted
|
| Bloom |
Has catkins
|
| Wind sensitivity | Not sensitive to (sea) wind |
Diseases
| Sensitive to the Following Diseases | Information not available |
Harvest/recognition in winter
The leaves are not aromatic and the buds are not sticky. The twigs are brownish and break off easily. However, identification is not easy because there are many hybrids with the Goat Willow. This Salix x rubens hybrid is much more common than pure Crack Willows.
Light requirement of the Willow (Crack)
Suitable soil types for the Willow (Crack)
| Soil type | Suitability |
|---|---|
| light clay |
|
| heavy clay |
|
| sand |
|
| peatland |
|
| Loam |
|
| Moerig op zand |
|
| Lichte zavel |
|
| Zware zavel |
|
Humidity
Suitable acidity level for the Willow (Crack)
Nutritional needs of the Willow (Crack)
| 1. | Very nutrient-poor soil |
| 2. | Very nutrient-poor to nutrient-poor soil |
| 3. | Nutrient-poor soil |
| 4. | Nutrient-poor to moderately nutrient-rich soil |
| 5. | Moderately nutrient-rich soil |
| 6. | Moderately nutrient-rich to nutrient-rich soil |
| 7. | Nutrient-rich soil |
| 8. | Extremely nutrient-rich soil |
| 9. | Very extremely nutrient-rich soil |
Humidity
| 1. | Extremely dry soils |
| 2. | Extremely dry to dry soils |
| 3. | Dry soils |
| 4. | Dry to dry/moist soils |
| 5. | Dry/moist soils |
| 6. | Dry/moist to moist soils |
| 7. | Moist soils |
| 8. | Moist to wet soils |
| 9. | Wet soils |
To be applied in landscapes
| Landscape | Suitability |
|---|---|
| Agroforestry |
|
| Hedge |
|
| Hedge |
|
| Forest |
|
| Feeding hedge |
|
| Back yard |
|
| Small back yard |
|
| Solitary |
|
| Wood wall |
|
Cultural-historical value
Insects
| How many insects typically live on this tree/plant? | 450 |
| Which insect groups live on this tree/plant? |
|
| Are there insects dependent on this species? | No |
| Which insect species are dependent on this tree/plant? |
Birds
| Average number of birds per tree/plant? | |
| Which bird groups live on this tree/plant? |
|
Mammals
| Average number of mammals per tree/plant? | |
| Which mammal groups live on this tree/plant? |
|
| Are there mammals dependent on this species? | No |
| Which mammal species are dependent on this tree/plant? |
Bloom Period
| Summer | April Up to May |
Tree Species
| Tree species that this tree prefers to grow with |
|
Suitable for mammals?
| Mammal | Suitability |
|---|---|
| Horse |
|
| Human |
|
| Cow |
|
| Pig |
|
| Sheep |
|
| Roe deer |
|
| Beavers |
|
| Badgers |
|
| Squirrel |
|
| Ferret |
|
| Goat |
|
| Herbivorous rodents |
|
| Deer |
|
| Dog |
|
| Cat |
|
| Chicken |
|
| Mouse |
|
| Foxes |
|
| Wild boar |
|
Explanation
Explanation
Edibility
- Toxic: This tree or shrub is toxic to mammals and absolutely unsuitable for consumption.
- Very unsuitable: This tree or shrub is unsuitable for consumption by mammals and can be harmful.
- Unsuitable: This tree or shrub is generally unsuitable for consumption by mammals and can have adverse effects.
- Moderately suitable: This tree or shrub is moderately suitable as food for mammals, possibly with certain risks or limitations.
- Suitable: This tree or shrub is generally suitable as food for mammals, with little to no risks.
- Very suitable: This tree or shrub is very suitable as food for mammals, safe, and of high nutritional value.
Trunk Height
Average Trunk Height (hg) of the basal area median tree
Information not available
Trunk Diameter
(dg) (1.30m) of the basal area median tree.
Information not available
Aboveground Biomass
in whole kgInformation not available
Belowground Biomass
in whole kgInformation not available
Substance Binder
| Which substances can be bound or absorbed? |
CO2
Particulate matter
|
Carbon Attraction (kf)
| (dg) (1.30m) of the basal area median tree | Deciduous Trees (Kf = 0,48) |
Warming Resistance
| This tree is well resistant to the warming (plus 3 degrees) of our climate and fits into the future of our climate (heat and drought resistant). | No |
CO2
| 0. | not filled in |
| 1. | no storage |
| 2. | low storage |
| 3. | moderate storage |
| 4. | high storage |
| 5. | very high storage |
Fine Dust
| 0. | not filled in |
| 1. | no capture capacity |
| 2. | low capture capacity |
| 3. | moderate capture capacity |
| 4. | high capture capacity |
| 5. | very high capture capacity |
This is what an adult tree Willow (Crack) looks like
This is what a Willow (Crack) in bloom looks like
This is what the leaf of a Willow (Crack) looks like
