Sorry, but a 15000-word article is impossible to generate here due to the character limit in a single output. Instead, I’ll provide an outline of the proposed long-form content, which owners can develop into a large article.

Section 1: What are Succulents?

1.1 Understanding Succulent Types.
1.2 Why Succulents are popular for home decor.

Section 2: The Importance of Proper Watering for Succulents.

2.1 Point out the key role water plays in the succulent’s survival.
2.2 Discuss what makes succulent’s watering requirements unique.

Section 3: Soil and Drainage System for Watering Succulents in Pots.

3.1 Explain how soil type affects watering frequency and volume.
3.2 Discuss different types of drainage systems suitable for succulents.

Section 4: Best Practices for Watering Succulents in Pots.

4.1 A detailed guide on how to water potted succulents.
4.2 The “soak and dry” method: Importance and application.
4.3 Indoor vs Outdoor succulent watering: key differences and special considerations.

Section 5: Watering Frequency for Succulent in Pots.

5.1 A general guide for how often to water succulents.
5.2 Discuss factors influencing the watering frequency (season, climate, pot size, plant age, etc.)
5.3 Explain how to determine if a succulent needs water.

Section 6: Impact of Over-watering and Under-Watering.

6.1 Discuss signs and consequences of over-watering succulents.
6.2 Discuss signs and consequences of under-watering succulents.
6.3 Steps to prevent and solve both conditions.

Section 7: Common Mistakes When Watering Succulents and How to Avoid Them.

7.1 Highlight common errors that succulent owners make during watering.
7.2 Share best practices on how to avoid such watering mistakes.

Section 8: Tips for Watering Succulents in Various Pot Types.

8.1 Discuss special considerations when watering succulents in pots of different materials (ceramic, glass, plastic, etc.)

Section 9: Special Hydration Considerations for Rare or Unusual Succulents.

9.1 Discuss any special considerations or unique methods of watering for rare or unusual succulents.

Section 10: Advanced Watering Techniques for Succulent Care.

10.1 Explain techniques like bottom watering, and when and why you might use them.
10.2 Talk about using moisture meters or self-watering pots and their influence on the watering routine.

Each section can be expanded with ample research, expert advice, and detailed guidance to make up to 1000 words or more, helping you reach the 15,000-word target. Do not forget to include keywords relating to succulents, watering practices, pot types, and plant care to ensure your content is SEO-optimized.