Rhus coriaria seeds, tanner's sumac

Sowing **Rhus** (sumac) seeds is an accessible method for growing this ornamental shrub or small tree, often prized for its colorful foliage and decorative fruits. Here is a step-by-step guide to successfully sowing Rhus seeds:

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### **Steps for sowing Rhus**

#### **1. Sowing period:**
- **Outdoors**: Autumn, to take advantage of natural stratification.
- **Indoors**: From February to April, after artificial stratification.

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#### **2. Harvesting or purchasing seeds:**
- **Seed harvest**:
- The seeds are contained in clusters of red or brownish fruits, harvested in the fall. Clean them to remove any pulp.

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#### **3. Seed preparation:**
**Rhus** seeds have a hard coat and require scarification or stratification to break their dormancy.

##### **Scarification:**
1. **Mechanical scarification**:
- Gently rub the seed shell with sandpaper to refine their envelope.
2. **Thermal scarification**:
- Immerse the seeds in hot water (80°C) and let them soak until the water cools (approximately 12 hours).

##### **Cold stratification (optional)**:
1. Mix the seeds with moist sand or peat.
2. Place them in an airtight plastic bag or container.
3. Store them in the refrigerator at **4°C to 5°C** for **4 to 6 weeks**.
4. Check regularly that the substrate remains slightly moist.

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#### **4. Substrate preparation:**
- **Substrate type**:
- Mix seed starting soil with sand or perlite (2:1) for good drainage.
- **Disinfection (optional)**:
- Heat the substrate to 100°C for 30 minutes to eliminate pathogens.

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#### **5. Sowing the seeds:**

##### **In pots or boxes:**
1. **Filling**:
- Fill the containers with the prepared substrate.
2. **Seed Arrangement**:
- Sow the seeds at a depth of **1 to 2 cm**.
3. **Watering**:
- Lightly moisten the substrate with a spray bottle or a fine-spout watering can.

##### **In the open ground (autumn)**:
1. **Soil preparation**:
- Loosen the soil and add sand to improve drainage if necessary.
2. **Seed Arrangement**:
- Sow directly to a depth of **2 cm**.
3. **Spacing**:
- Leave about **30 cm** between seeds.

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#### **6. Germination conditions:**
- **Ideal temperature**:
- Seeds germinate best between **18°C and 25°C**.
- **Light** :
- Seeds do not need direct light to germinate.
- **Humidity** :
- Maintain constant humidity by covering the pots with plastic film or a mini-greenhouse.
- **Germination time**:
- Germination can take between **4 and 12 weeks**, depending on species and conditions.

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#### **7. Care after germination:**
1. **Remove the cover**:
- As soon as the first seedlings appear, remove the plastic film to avoid excess humidity.
2. **Watering**:
- Keep the substrate slightly moist, but allow it to dry slightly between waterings.
3. **Thinning**:
- If the seedlings are too close together, thin them out to leave about **10 cm** between them.

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#### **8. Transplanting:**
- **When to transplant**:
- When the seedlings reach a height of **10 to 15 cm** and their roots are well developed.
- **Planting into pots**:
- Transplant the young plants into individual pots with a similar substrate.
- **Planting in open ground**:
- Wait until the plants are about **30 cm** tall before planting them outdoors.

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#### **9. Planting in open ground:**
1. **Location**:
- Choose a sunny or partially shaded location with well-drained soil.
2. **Spacing**:
- Plant sumacs about **1 to 3 meters** apart, depending on the species.
3. **Watering**:
- Water lightly after planting to encourage rooting.

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#### **10. Long-term maintenance:**
1. **Watering**:
- Rhus tolerates drought well once established. Water only in case of prolonged drought.
2. **Fertilization**:
- Add compost or organic fertilizer in spring to stimulate growth.
3. **Size**:
- Prune dead or diseased branches to maintain good structure.
4. **Control**:
- Some Rhus species, such as Virginia sumac, can become invasive. Monitor their spread.

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### **Additional Tips:**
1. **Ornamental plant**:
- Rhus are often used for their flamboyant autumn foliage and their ability to stabilize soils.
2. **Invasive species**:
- Find out about the species you are planting, as some are considered invasive in certain regions.
3. **Biodiversity**:
- Rhus fruits attract birds and promote biodiversity.

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### **Conclusion :**
Sowing Rhus is a simple and rewarding way to grow these elegant and hardy shrubs and trees. With proper care and monitoring, you can enjoy their beauty and benefits in your garden. 🌱🌳