How to Get Hydrangea Seeds? A Step-by-Step Guide
Getting hydrangea seeds involves careful harvesting of mature flowers, followed by proper extraction and drying. While not as common as propagation through cuttings, obtaining seeds is possible with patience and attention to detail, and may allow for creating new and unique hybrid varieties.
Hydrangeas, known for their stunning blooms, are typically propagated using cuttings. However, collecting seeds offers a unique opportunity to grow hydrangeas from scratch and potentially develop new cultivars with different flower colors, sizes, or growth habits. This article will guide you through the process of obtaining hydrangea seeds, ensuring successful germination and growth.
Understanding Hydrangea Flowers and Seeds
Hydrangeas are not like many other plants where the seeds are immediately visible or easy to access. Their flowers come in various forms, some of which are sterile. It’s crucial to understand the floral structure to identify where the seeds reside.
- Fertile vs. Sterile Flowers: Many hydrangea varieties feature both fertile and sterile flowers. Fertile flowers are small and inconspicuous, located in the center of the flower head. These are the ones that produce seeds. Sterile flowers are the large, showy petals that attract pollinators.
- Flower Types: Understanding the type of hydrangea you have – macrophylla, paniculata, arborescens, etc. – is important. While the process is generally similar, the timing and visual cues might vary slightly. Macrophylla hydrangeas, for instance, are renowned for their changing color depending on soil pH.
- Seed Location: Hydrangea seeds are tiny, dark, and found within the dried flower heads of the fertile flowers, particularly the ones that have been pollinated.
Identifying and Collecting Seed-Bearing Flowers
Finding fertile flowers that have successfully produced seeds requires a keen eye and knowledge of the hydrangea variety.
- Look for Dried Flower Heads: After the blooming season, leave the flower heads on the plant. Allow them to dry and turn brown. These are the flowers most likely to contain mature seeds.
- Inspect Fertile Flowers: Examine the small, inconspicuous flowers in the center of the dried flower head. Look for signs of seed development, such as dried seed capsules.
- Harvest Timing: The ideal time to harvest is late autumn or early winter, after the flower heads have fully dried but before they’re completely deteriorated by the weather.
- Gentle Removal: Carefully cut off the dried flower heads using pruning shears. Avoid damaging the surrounding plant.
Extracting and Cleaning Hydrangea Seeds
Once you’ve collected the flower heads, the next step is to extract and clean the seeds. This requires a delicate touch to avoid damaging the seeds.
- Drying Flower Heads: Allow the cut flower heads to dry completely indoors for several weeks, ensuring they are not exposed to moisture.
- Gentle Crushing: Gently crush the dried flower heads over a clean surface or container. This will release the seeds from the dried flower parts.
- Separation: Separate the seeds from the chaff (dried flower parts) using a fine-mesh sieve or by gently blowing away the lighter debris.
- Winnowing: Use the winnowing technique (gently shaking and blowing across the container) to help separate the seeds from the remaining debris.
- Seed Inspection: Inspect the seeds, discarding any that appear damaged or immature. Healthy seeds are typically dark in color.
Storing Hydrangea Seeds
Proper storage is critical for maintaining the viability of hydrangea seeds.
- Drying: Ensure the seeds are completely dry before storing them.
- Airtight Container: Store the seeds in an airtight container, such as a glass jar or resealable plastic bag.
- Cool, Dark Place: Store the container in a cool, dark, and dry place, such as a refrigerator or a cool basement.
- Labeling: Label the container with the date of collection and the hydrangea variety.
Germinating Hydrangea Seeds
Germinating hydrangea seeds can be a slow and sometimes challenging process, but with the right approach, you can achieve success.
- Cold Stratification: Hydrangea seeds typically require a period of cold stratification to break dormancy. Place the seeds in a damp paper towel inside a sealed plastic bag and refrigerate them for 4-8 weeks.
- Seed Starting Mix: Use a well-draining seed starting mix.
- Sowing: Sow the seeds on the surface of the soil and gently press them down. Do not bury them too deeply, as they need light to germinate.
- Moisture: Keep the soil consistently moist but not waterlogged. Use a spray bottle to mist the soil regularly.
- Light: Provide indirect sunlight or use grow lights.
- Temperature: Maintain a temperature of around 65-70°F (18-21°C).
- Patience: Germination can take several weeks or even months. Be patient and continue to provide proper care.
Common Mistakes to Avoid
Several common mistakes can hinder your efforts to obtain and germinate hydrangea seeds. Avoiding these errors will increase your chances of success.
- Harvesting Too Early: Harvesting flower heads before they are fully dried can result in immature seeds that will not germinate.
- Improper Drying: Failing to properly dry the flower heads and seeds can lead to mold growth and seed decay.
- Incorrect Storage: Storing seeds in a warm or humid environment can reduce their viability.
- Overwatering: Overwatering the seeds during germination can lead to fungal diseases and seed rot.
- Impatience: Giving up too soon when germination takes longer than expected.
| Mistake | Consequence | Solution |
|---|---|---|
| Harvesting Too Early | Immature, non-viable seeds | Wait until flower heads are fully dried and brown |
| Improper Drying | Mold growth, seed decay | Ensure thorough drying before storage |
| Incorrect Storage | Reduced seed viability | Store in a cool, dark, and dry place |
| Overwatering | Fungal diseases, seed rot | Maintain consistent moisture, but avoid waterlogging |
| Impatience | Missed germination opportunities | Continue providing proper care, even if germination is slow |
Frequently Asked Questions (FAQs)
How can I tell if a hydrangea flower head has viable seeds?
Viable seeds are usually dark and plump. Flowers that were successfully pollinated will have seed capsules inside, which are harder to find in the more showy varieties. Dried, shriveled, or pale seeds are unlikely to germinate.
Do all hydrangea varieties produce seeds?
While all hydrangeas technically produce seeds, some varieties, especially those with mostly sterile flowers, produce very few, if any, seeds. Varieties with more fertile flowers are more likely to yield a greater quantity of seeds.
Can I use seeds from a hybrid hydrangea?
Yes, you can, but the resulting plants may not be true to type. They might exhibit characteristics from either parent plant or even unexpected traits. This is the fun of growing from seeds and trying to make new hybrids.
How long do hydrangea seeds remain viable?
Hydrangea seeds typically remain viable for 1-2 years if stored properly. However, their germination rate may decline over time. Using seeds as soon as possible after collection is recommended.
What is cold stratification and why is it necessary?
Cold stratification is the process of exposing seeds to cold, moist conditions to break dormancy. It mimics the natural winter conditions that seeds would experience in the wild and signals them to germinate in the spring.
What is the best soil mix for germinating hydrangea seeds?
A well-draining seed starting mix is ideal. You can also create your own mix using equal parts of peat moss, perlite, and vermiculite. Ensure the mix is sterile to prevent fungal diseases.
How often should I water the seeds after sowing?
Keep the soil consistently moist but not waterlogged. Use a spray bottle to mist the soil regularly, especially when the top layer feels dry.
How much light do hydrangea seedlings need?
Hydrangea seedlings need indirect sunlight or filtered light. Avoid direct sunlight, which can scorch the delicate leaves. Grow lights can be used if natural light is insufficient.
When can I transplant the seedlings into larger pots?
Once the seedlings have developed several sets of true leaves and are large enough to handle, you can transplant them into individual pots. Use a well-draining potting mix.
How long does it take for a hydrangea grown from seed to flower?
It typically takes 2-3 years or longer for a hydrangea grown from seed to flower. Be patient and provide proper care to encourage flowering.
Are there any specific fertilizers recommended for hydrangea seedlings?
Use a balanced, water-soluble fertilizer diluted to half strength. Fertilize the seedlings every few weeks during the growing season.
What are some common problems encountered when growing hydrangeas from seed?
Common problems include damping-off, fungal diseases, and pest infestations. Ensure proper ventilation, avoid overwatering, and inspect the seedlings regularly for signs of problems. Treat any issues promptly with appropriate fungicides or pesticides.