Plumerias need very good drainage. Use a good draining soil with natural compost. Mix cactus soil with pumice to give good results. If your soil is poor, plant plumerias a raised bed with a good draining mix.
Plumerias like full sun. Some Plumerias will not bloom if they do not have sufficient sun light. For good blooming, 6 to 8 hours of direct sunlight is needed.
Aphids cause leaves to curl. Use organic (environmentally friendly) insecticide to control. Spray under the leaves. Mites will cause spotting on the leaves. Use organic insecticide recommended by your local garden center. Whitefly can be easily controlled with a strong stream of water. A small amount of dish soap in water will also do a good job of controlling the whitefly.
ALWAYS FOLLOW THE DIRECTIONS ON THE INSECTCIDIE CONTAINER
Water is very important to your Plumerias. Your plant must have enough water in the summer months. Without adequate water your Plumeria will go into suspended state or dormancy. The plant will abort flower stalks and the leaves will drop. Allow plumerias to go dry in between watering, and then a deep soaking is in order. Watering depends on the daytime temperature and humidity, a good balance is essential. Plumerias do not like standing water, do not use catch bowl/plate under a potted Plumeria. When the plant drops its leaves in the cool Fall and Winter months, DO NOT WATER, only enough water is necessary to keep the soil slightly moist. If the temperature in your environment drops to 32 degrees, the plant may be bare rooted and stored in a freeze protected area. The plant can be replanted in the Spring and will do well.
Six to eight (6 – 8) hours of direct sunlight is needed for good blooming of your plumerias. Some varieties require some shade from the hot inland sun in the summer months.
To encourage blooming, Plumerias need a high phosphorus fertilizer. Refer to the “N P K” numbers on the container. The “P” is the Phosphorus content. Superbloom, Superphosphate and Hi-Bloom are some examples. You can use a 10-52-10 water soluble fertilizer at a rate of 1 t0 2 teaspoons per gallon of water. A weaker solution and using it more often gives very good results if your plant are in pots. For plants in the ground, a 3-12-12 will work well. Apply at a rate of 1 pound per inch of trunk diameter, spread evenly to the drip line of the plant. Depending on your soil type, 2 to 3 applications a year is sufficient.
In Southern California, we have a wide range of micro-climates. You must take into account conditions in your area to best determine your water and feeding schedules.