Seeds of Acer Shirasawanum "Palmatifolium", Shirasawa Maple

Sowing maple seeds is a common method for growing these magnificent trees, but a few specific points must be considered to ensure successful germination. The genus Acer includes many species, such as the Japanese maple (Acer palmatum), the Norway maple (Acer platanoides), and the sycamore maple (Acer pseudoplatanus). Here are the steps to follow when sowing maple seeds:

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### **Materials needed:**
- Seeds of **Acer**.
- Well-draining, light and slightly acidic substrate (seedling soil, mixture of sand and soil).
- Pots or seed trays.
- Plastic bag or box for lamination.
- Watering can or sprayer.
- A cool space or refrigerator for cold stratification (if necessary).

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### **Steps for sowing Acer seeds:**

#### 1. **Seed preparation:**
Maple seeds are generally samaras, which are winged seeds that allow for wind dispersal. These seeds often require cold stratification to stimulate germination.

- **Cold stratification**:
- **When to stratify**: If you sow maple seeds in the fall, they can naturally undergo cold stratification during the winter. However, if you sow in the spring or winter, it is best to stratify the seeds by placing them in a **plastic bag** with **damp sand** or **damp peat**, then putting them in a refrigerator at a temperature of **4°C** for **4 to 6 weeks**.
- This cold period is crucial for the seeds to overcome dormancy and germinate successfully.

#### 2. **Substrate preparation:**
Prepare a light, well-draining substrate to promote maple seed germination. A mixture of **seed-starting mix** and **perlite** or **sand** is ideal.

- Moisten the substrate before sowing the seeds. It should be moist, but not soggy.

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#### 3. **Sowing the seeds:**
Once you have stratified the seeds (if necessary), you can proceed to sowing:

- **In pots or seed trays**:
- Fill **pots** or **seed trays** with the prepared substrate.
- Sow the seeds at a depth of **1 cm**. Avoid burying them too deep, as they need light to germinate.
- If you sow several seeds in the same pot or container, space them **2 to 3 cm** apart to prevent them from competing with each other during germination.

- **Direct sowing**:
- You can sow the seeds directly in the ground, but be sure to choose a well-drained and sunny spot. Sow the seeds at a depth of **1 to 2 cm**, spacing them about **5 to 10 cm** apart.

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#### 4. **Germination conditions:**
- **Temperature**: Maple seeds generally germinate best at a temperature of **15°C to 20°C**. Therefore, it is recommended to sow the seeds indoors during the spring if you do not have favorable outdoor temperatures.
- **Light**: Maple seeds need light to germinate, so don't bury them too deeply.
- **Humidity**: Keep the substrate moist but not soggy. Use a **sprayer** to gently moisten the soil.
- **Germination**: Maple seeds should begin to germinate within **4 to 8 weeks**, depending on temperature and humidity conditions.

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#### 5. **Post-germination care:**
- **Watering**: Once the seeds have germinated and the young seedlings are visible, water them regularly, but be careful not to overwater them. The moisture should be constant but moderate.
- **Light**: Young plants need plenty of **indirect light**, but not direct sunlight, as this could burn the young leaves.
- **Protection against pests**: Monitor young plants for any signs of disease or harmful insects, such as aphids.

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#### 6. **Transplanting and planting in open ground:**
- **When to transplant**: When the young plants have developed their first true leaves and are about **5 to 10 cm** tall, you can transplant them into individual pots.
- **In open ground**:
- When the seedlings reach **15 to 20 cm** in height, they can be transplanted into open ground. Choose a location in **full sun** or **partial shade**, with **well-drained** and **moderately fertile** soil.
- Plant young trees **2 to 3 meters** apart to allow them to develop properly.

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### **Additional tips:**
1. **Mulching**: Apply some **mulch** around young plants to retain moisture and prevent weeds.
2. **Staking**: If necessary, install stakes to support the young plants until they are sturdy enough to stand on their own.
3. **Patience**: Maple trees can grow relatively slowly, so be patient and continue to care for young trees during their development.