Collecting and Preparing Acer Seeds for Spring Sowing

As autumn sets in, it’s the perfect time to collect seeds from trees such  as Acer palmatum. These trees, known for their stunning autumn foliage, also produce seeds that can be harvested and stored for future growth. Here’s a step-by-step guide to help you gather and prepare these seeds for planting next spring.

Step 1: Collect the Seeds

Once autumn arrives, you’ll notice the Acer seeds—sometimes called “samara”—begin to ripen. The best time to collect them is when they have dried out naturally on the tree but before they drop to the ground. You can tell they’re ready when they turn a brown or golden colour.

Step 2: Dry the Seeds

After collecting the seeds, it’s important to dry them in a room-temperature environment for a few days. Lay them out on a flat surface, ensuring they’re in a well-ventilated space. This drying process ensures that excess moisture is removed before storing or preparing the seeds for germination.

Step 3: Stratification – Mimicking Winter

Acer seeds have evolved to avoid germinating immediately after falling from the tree. Instead, they require a period of cold weather to break the seeds dormancy.  By using a  process known as stratification, which mimics the winter environment you can break this dormancy. 

To break this dormancy, you’ll need to simulate winter by placing the seeds in cold storage for 60 to 90 days. Follow these steps:

1. Prepare the Seeds: Mix your seeds with an equal amount of perlite or sharp sand. This helps to prevent excess moisture build-up and improves air circulation around the seeds.

2. Bag and Label: Place the seed mix in a resealable plastic bag, label it with the date and type of seed, and ensure the bag is sealed tightly.

3. Freeze: Store the bag in the freezer for the required cold treatment, typically between 60 to 90 days. The freezing period mirrors the cold winter months, encouraging the seeds to lose their dormancy and get ready for germination in the spring.

Step 4: Sowing the Seeds

After the cold stratification process, your seeds are ready for sowing. The best medium to use is John Innes Compost No. 1, a compost blend that provides the ideal nutrients and drainage for young seedlings. Plant the seeds in individual pots or seed trays, water lightly, and place them in a sheltered spot to germinate as the spring temperatures warm up.

By following this process, you’ll give your Acer seeds the best chance to grow into healthy saplings, rewarding you with beautiful, delicate trees in the years to come.

Expect Genetic Variation

Unlike taking cuttings, which produce clones identical to the parent plant, growing from seeds introduces genetic variation. This means that the seedlings you grow may differ from the original plant in traits such as leaf shape, growth habit, or even the vibrancy of their autumn colour. In some cases, you may find that the new plants have a stronger or more intense autumn hue than the parent, making this method of propagation both exciting and full of possibilities.

By following this process, you’ll give your Acer seeds the best chance to grow into healthy saplings, rewarding you with beautiful, delicate trees in the years to come. Happy planting!