Plumeria seedlings can take several years to mature and produce their first blooms. The time it takes for Plumeria seedlings to bloom depends on various factors, including the growing conditions, the age of the seedlings when they were first planted, and the specific Plumeria species or variety.

Here are some general guidelines for the time it takes for Plumeria seedlings to bloom:

1. Seedling Age: Plumeria seedlings that are grown from seeds typically take longer to bloom compared to mature plants or those propagated from cuttings. It can take anywhere from 2 to 5 years or more for seed-grown Plumeria to reach maturity and produce their first flowers.
2. Growing Conditions: Providing optimal growing conditions can help speed up the time to bloom. Plumeria seedlings thrive in warm and sunny climates. Adequate sunlight, proper watering, well-draining soil, and regular fertilization can promote healthy growth and potentially lead to earlier flowering.
3. Plumeria Variety: The specific Plumeria species or variety also plays a role in the time it takes to bloom. Some varieties may naturally bloom earlier than others. For example, some dwarf or compact Plumeria varieties tend to bloom sooner than larger, tree-like varieties.
4. Environmental Factors: Factors such as temperature, humidity, and seasonal changes can influence the flowering time of Plumeria. Warmer and consistent temperatures are generally more conducive to flowering.
5. Size and Health: The overall size and health of the seedlings can affect when they bloom. Healthy, well-nourished seedlings are more likely to bloom earlier than stressed or undernourished ones.
6. Pruning and Care: Proper care, including pruning and shaping of the seedlings, can encourage branching and potentially lead to earlier flowering. Pruning can help create a more robust and branching plant structure.
7. Nutrient Availability: Ensuring that the seedlings receive the necessary nutrients, especially phosphorus (P), can promote flower bud formation and blooming. Use a balanced fertilizer with a higher middle number (e.g., 10-30-10) to support flowering.

In summary, while Plumeria seedlings can take several years to bloom, providing ideal growing conditions, proper care, and attention to their needs can help expedite the process. Additionally, the specific Plumeria variety you are growing will also influence the time it takes for the seedlings to produce their first beautiful blooms.