To effectively preserve plum seeds for future planting, the most crucial step involves replicating their natural winter dormancy period, known as cold stratification. This process prepares the seeds for germination.
The Science Behind Preserving Plum Seeds
Plum seeds, like many temperate fruit seeds, require a period of cold, moist conditions to break dormancy. This naturally occurs when plums fall to the ground in autumn and their seeds spend the winter embedded in cool, damp soil.
- Mimicking Nature: As per the references, "Keeping the seeds in the fridge mimics the process that would take place if the plum were to have fallen to the ground after the summer growing season ended." This artificial winter period signals to the seed that spring is approaching, making it ready to sprout.
Step-by-Step Guide to Plum Seed Preservation (Cold Stratification)
Preserving plum seeds involves a straightforward process that primarily utilizes your refrigerator.
Materials Needed
| Material | Purpose |
|---|---|
| Plum Seeds | The item to be preserved |
| Paper Towels | To provide a damp medium for the seeds |
| Ziplock Bag/Airtight Container | To hold seeds and maintain moisture |
| Spray Bottle (optional) | For controlled dampening |
| Permanent Marker | For labeling |
The Preservation Process
Follow these steps to successfully cold stratify your plum seeds:
- Clean the Seeds:
- Thoroughly clean the plum pits (stones) to remove all fruit flesh. Any remaining fruit can lead to mold growth during stratification.
- You can gently scrub them under running water or soak them briefly and then rub off any stubborn pulp.
- Prepare the Moisture Medium:
- As stated in the reference, "You can put them in a damp paper towel in the refrigerator." Dampen a paper towel (or a few, depending on the number of seeds) with water. It should be moist, but not dripping wet. Squeeze out any excess water.
- Enclose the Seeds:
- Place your cleaned plum seeds onto the damp paper towel.
- Fold the paper towel around the seeds to create a small packet.
- Place this packet into a sealable plastic bag (like a Ziplock bag) or an airtight container.
- Tip: Label the bag with the date and seed type (e.g., "Plum Seeds - Jan 15").
- Refrigerate:
- Place the sealed bag or container in the crisper drawer of your refrigerator. The ideal temperature range for stratification is typically between 34°F and 41°F (1°C and 5°C).
- This period of cold is essential. Most plum varieties require 2-3 months (approximately 60-90 days) of cold stratification.
- Monitor Regularly:
- Check the seeds periodically (every 2-3 weeks) to ensure the paper towel remains damp. If it starts to dry out, add a small amount of water to re-dampen it.
- Also, inspect for any signs of mold. If mold appears, remove the affected seeds (if any), re-clean unaffected ones, and re-pack them in a fresh, damp paper towel. Adequate ventilation in the bag (e.g., opening it briefly) can help prevent mold.
After Preservation: Preparing for Planting
Once the cold stratification period is complete, your plum seeds are ready to be planted. They should be removed from the refrigerator and planted directly into soil, ideally in the spring after the last frost. Some seeds may even show signs of sprouting inside the bag; these should be handled with extra care during planting.
