Yes, covering Plumeria seeds with a transparent lid or plastic wrap is a common practice during the germination phase. Here’s why it’s beneficial and how to do it:

Benefits of Covering Plumeria Seeds for Germination:

1. Maintains Humidity: Plumeria seeds require a high level of humidity to germinate successfully. Covering the seeds with a transparent lid or plastic wrap helps create a microenvironment with elevated humidity, which is essential for the initial stages of germination.
2. Prevents Drying Out: By covering the seeds, you can prevent the soil surface from drying out too quickly. This is especially important in dry or arid climates where rapid evaporation can occur.
3. Protects from Drafts: A transparent lid or plastic wrap can also provide some protection from drafts or sudden temperature changes, creating a stable and favorable environment for germination.

How to Cover Plumeria Seeds for Germination:

1. Select a Container: Start with a clean, shallow container or seed tray. Ensure that it has drainage holes to prevent waterlogging.
2. Plant the Seeds: Plant the Plumeria seeds at the recommended depth (usually about 1/4 inch deep) in a well-draining potting mix.
3. Water Gently: Water the soil lightly to ensure it’s evenly moist but not waterlogged.
4. Cover with Plastic Wrap or Lid: Place a sheet of transparent plastic wrap or a transparent lid over the container to create a sealed environment. Ensure that it covers the entire surface and is secured in place.
5. Monitor and Adjust: Check the seeds regularly to ensure that the soil remains lightly moist. If condensation forms inside the cover, it’s a sign that the humidity level is adequate. If the soil appears too dry, you can mist it lightly with a spray bottle.
6. Partial Ventilation: As soon as the Plumeria seedlings begin to emerge and develop their first set of true leaves (distinct from the cotyledons), you can start to provide partial ventilation by opening the lid or creating small openings in the plastic wrap. This allows the seedlings to gradually acclimate to lower humidity levels.
7. Remove Cover Gradually: Over the course of several days to a week, gradually reduce the coverage until you can remove the transparent lid or plastic wrap completely. At this stage, the seedlings should be ready to grow in normal air conditions.

Remember that the goal is to create a humid and stable environment for germination, and covering the seeds initially helps achieve this. Once the seedlings have emerged, they can be transitioned to normal growing conditions.