Germinating hydrangea seeds can be a challenging process, as hydrangeas are typically propagated through other methods like cuttings or division. However, if you're interested in trying to grow hydrangeas from seeds, here are some general instructions to help you:

1.     Seed Stratification: Hydrangea seeds require a period of cold stratification to break their dormancy. Moisten a paper towel or coffee filter, place the seeds on it, and fold it over to cover them. Put the moistened seeds in a sealable plastic bag and refrigerate them for 4-6 weeks at a temperature around 35-41°F (2-5°C). This mimics the natural winter conditions that hydrangea seeds need to germinate.

2.     Seed Sowing: After the cold stratification period, prepare a seed tray or small pots with a well-draining seed-starting mix. Moisten the soil lightly before sowing the seeds. Sow the hydrangea seeds on the surface of the soil and press them gently into the soil, but do not cover them as they require light to germinate.

3.     Germination Conditions: Place the seed tray or pots in a warm location with indirect sunlight. The ideal temperature for germination is around 68-75°F (20-24°C). Keep the soil lightly moist, but avoid overwatering. You can cover the tray or pots with a plastic dome or plastic wrap to create a humid environment that helps retain moisture.

4.     Seedling Care: Be patient, as germination for hydrangea seeds can be slow and may take several weeks or even months. Once the seedlings have developed several sets of true leaves, they can be transplanted into individual pots or containers. Use a well-draining potting mix and ensure the pots have drainage holes. Provide the seedlings with bright, indirect light and maintain a temperature range of 65-75°F (18-24°C).

It's important to note that growing hydrangeas from seeds can be a lengthy and uncertain process. Additionally, the resulting plants may not exhibit the same characteristics as the parent plant, as hydrangeas are often propagated through other methods to maintain specific traits. Patience, experimentation, and a love for gardening are key when growing hydrangeas from seeds.

The germination rate of hydrangea seeds can vary significantly depending on the specific hydrangea species or variety, seed quality, and germination conditions provided. In general, hydrangea seeds have a relatively low germination rate compared to other plants. On average, the germination rate for hydrangea seeds can range from 10% to 40%.

It's important to note that hydrangeas are typically propagated through other methods like cuttings or division because growing hydrangeas from seeds can be challenging. Hydrangea seeds have a hard outer coat that can inhibit germination, and the resulting plants may not exhibit the same characteristics as the parent plant. Therefore, if you're specifically aiming to propagate a particular hydrangea variety, it's often more reliable to use other propagation methods.

If you decide to try germinating hydrangea seeds, be prepared for a lower germination rate and have patience as the process can be slow. It's also worth noting that some hydrangea varieties may have higher or lower germination rates compared to the average, so the actual germination rate can vary from one variety to another.