Step 1 — Obtain Hydrangea Seeds
You can purchase hydrangea seeds from your local gardening center.
If you have existing mature hydrangea plants, you can obtain seeds from its flowers as well. It is best to obtain seeds in the fall, when the flowers are fading. Choose a spent flowerhead, and allow the flowers to darken. Once the flower looks fully dark and dry, cut it below the pod. Leave the pod to dry for about a week, after which you can retrieve the seeds inside it. The seeds are minute and black in color.
You can either sow the seeds in the fall or cover and store the seeds in a dry, cool area through the winter to sow next spring.
Step 2 — Sow the Seeds
Choose a good-quality pot or container and fill it with a potting mix or soil high in nutrients and organic matter. Starting with nutrient-rich soil is beneficial to the plant. The soil must be well-drained and moist at the same time.
Leave a couple of inches free at the top of the pot. To sow the seeds, just dust the seeds on top of the soil. Do not disturb the soil or try to mix the seeds with the soil.
Keep the soil moist at all times without making it soggy. Once the plant germinates and develops strong roots, it can be moved outside to a bright location where it will get enough sunlight. However, you must protect the plant from intense heat.
If you are sowing the seeds in fall, keep the pot indoors in a well-lit area throughout the winter. Keep it away from heat sources indoors.
The seeds will soon germinate, and you can move the pot outdoors, transplanting in spring.
Step 3 — Care and Maintenance
Make sure the plant is adequately watered at all times. Never over-water, as this will cause waterlogging and harm the roots.
Remove any dead growth and stubs, as this could cause infections or disease in the plant. Also remove all dead flowers promptly.
If your hydrangea plant gets too big, it may have to be pruned so that you can maintain a presentable shape. Depending on the species, the pruning time is different. If you are unsure, it is best to consult the local greenhouse on the best time to prune your hydrangea.
So long as you water the plant regularly and provide it with adequate nutrients, your hydrangeas will continue to bloom and brighten your garden.