Newly germinated plumeria seedlings putting out multiple branches can occur due to several factors, primarily related to genetics and growth conditions. Here are some reasons why this might happen:

Genetic Variation: like many plants, Plumeria exhibits genetic variation within its species. Some plumeria seeds may carry genetic traits that predispose them to produce multiple branches at an early stage. This is a natural variation and can result in seedlings with multiple stems.

Stress: Environmental stress during the germination and early growth stages can trigger plumeria seedlings to develop multiple branches as a survival mechanism. Stressors like irregular watering, temperature fluctuations, or inadequate light can induce branching as the seedling seeks to increase its chances of survival.

Light Intensity: Plumeria seedlings are more likely to develop multiple branches if they receive lower light levels. When seedlings sense that light is limited, they may produce additional stems to capture more light for photosynthesis.

Spacing: If plumeria seeds or seedlings are crowded together in close proximity, they may compete for light and nutrients. This competition can lead to the development of multiple branches as each seedling tries to access essential resources.

Nutrition: Imbalanced or insufficient nutrition can also influence the branching pattern of plumeria seedlings. Inadequate nutrients can result in weaker, thinner stems, prompting the seedling to produce more branches for support and stability.

Age: Some plumeria seedlings naturally have a genetic predisposition to produce multiple branches from an early age. These seedlings may exhibit branching tendencies even when grown under ideal conditions.

Pruning: In some cases, accidental or intentional pruning during the early stages of seedling growth can lead to the development of multiple branches. Removing the primary shoot can encourage lateral shoots to take over as the main stems.

It’s important to note that while some plumeria seedlings may naturally develop multiple branches early on, most grow as single-stemmed plants. The branching pattern can vary widely among seedlings, even within the same batch of seeds.

If you want to encourage a specific branching pattern or ensure single-stemmed growth for your plumeria seedlings, it’s important to provide consistent and optimal growing conditions, including adequate light, proper nutrition, appropriate spacing, and careful monitoring for stress factors. Pruning or removing extra stems can also help shape the growth of your plumeria seedlings as they mature.