Plumeria plants are the perfect addition to any garden, and with the right fertilizer, they can produce beautiful vibrant flowers that will add a touch of tropical style to your outdoor space. Here we will discuss the best fertilizer for plumeria plants, so you can ensure that your blooms reach their full potential!
While you can neglect some tropical plants a little when it comes to feeding, this isn’t the case for Plumeria. They are heavy feeders and needing regular fertilizer to maintain healthy plants. Not only does fertilizer help to promote growth, it will increase disease resistance, and promote flowering. This article tells you which nutrients plants need to maintain baseline health as well as the extra boost they need to create fragrant flowers. Armed with this knowledge you’ll be able to start the optimal fertilizing regime for your frangipani.
Plumeria, also known as frangipani or ʻōhiʻa lehua, is a genus of flowering deciduous trees native to Central and South America, and the Caribbean. They are also widely cultivated in other parts of the world, especially in tropical regions. Plumeria trees grow so abundantly in Hawaii that many people believe it to be a native Hawaiian plant.
In summer the small trees produce clusters of beautiful, fragrant blooms. Plumeria flowers are one or more shades of white, yellow, pink, red and all the colors in between. Each flower has five waxy petals that slightly overlap each other. The sweet scent of plumeria blooms attracts hummingbirds, butterflies, and other pollinators.
Fertilizing plumeria in three simple steps
Fertilizing plumerias is an important part of their maintenance and is essential for their health and vitality.
Step 1
The most important factor is to ensure that the plumeria is growing in a healthy soil. This means that it contains the right balance of structural elements and nutrients. These support not only the plant, but also the microorganisms which live in the soil.
Microorganisms have an important role to support the health of the soil the health of the plant. Some of the microorganisms help to process nutrients into a form that the plant’s roots can absorb. Some actually produce nutrients themselves, and some help to protect the plant from disease or infection.
Step 2
Next it is important to understand the types of nutrients that plumeria plants need in order to thrive. The most important of these are nitrogen, phosphorus, and potassium. Nitrogen is essential for growth and development, and helps to promote leafy green growth and abundant blooms. Phosphorus is important for root and flower development, and potassium helps to improve the overall health of the plant.
All of these nutrients will be part of a good quality fertilizer. In addition to providing the necessary nutrients, fertilizers can also help to improve the soil quality around the plants. This is particularly true for soils that are low in organic matter. The addition of fertilizer can help to increase the amount of organic matter in the soil. This helps to increase soil fertility and improve the overall health of the plant.
Step 3
The third important factor is keeping up the supply of nutrients. A well fed plumeria plant will reward you with lots of new growth and flowers. Feed your plumeria with either a slow-release granular fertilizer or liquid fertilizer. If your plumeria is growing in the garden you might want to consider using an organic fertilizer. This is because anything you add to the soil has the potential to affect all lifeforms in the vicinity.
Best soil for growing plumeria
Tropical plants usually grow best in well-drained soils that are rich in organic matter. The soil will have some sand and/or volcanic rock minerals that help to give it structure. This is the type of soil that they would have in their natural environments so it’s not surprising that it’s what they like best. Organic matter helps to balance the water content of the soil. Secondly, it provides a home and food for microorganisms that are essential to soil health. Lastly, it provides the all-important nutrients that your plants need.
To understand the best soil type for your frangipani plants it helps to study the soil in one of the places that they grow best – Hawaii. The typical composition of soil in Hawaii can vary depending on the island, age, and water sources of the area. Generally, most soil in Hawaii is formed from volcanic rock, ash, and other igneous materials.
Common soil components in Hawaii include quartz, pyroxene, olivine, micas, and feldspars. These minerals are in clay, silt, and sand, as well as organic matter (humus). Soil in Hawaii tends to be rich in minerals, like iron, phosphorous, calcium, and sulfur. The presence of these minerals varies with the site location and elevation. There are also plenty of microorganisms like bacteria, algae and fungi that contribute to soil fertility and health. With soil like that it’s no wonder that plumeria grow so well there!
How to optimize your soil for growing Plumeria plants
If you are serious about growing Plumeria it’s worth testing your soil. At a minimum perform a home pH test on your garden soil using a kit available at most garden centers. An even better option is to take some samples of soil and have them professionally analyzed.
You are aiming to grow your Plumeria in a slightly acidic soil that has a loose sandy structure that is well-draining. The pH range should be between 6.0 and 6.5 but up to 7.0 is acceptable. Organic matter is essential as Plumeria plants require a lot of nutrients. It’s also important to make sure the soil is not waterlogged, as the roots of the Plumeria plant may rot if they are constantly submerged in water.
If you have a clay soil you will need to improve the drainage and internal structure of the soil to successfully grow Plumeria. Add some gypsum to help break up the clay. You can also add some coarse sand, biochar and/or crushed rock minerals to help create a loose and free-draining structure. Then add lots of organic matter such as compost or decomposed manure. Regularly adding organic matter as a fertilizer will help to maintain the soil quality. The best organic matter sources are compost, well-rotted manure or organic mulch. If you have sandy soil you should add organic matter because it improves the soil’s ability to retain moisture and nutrients.
Are coffee grounds good for Plumeria soil?
You may have seen that coffee grounds are a great option as a fertilizer for Plumeria. This is true, coffee grounds can be beneficial for plumeria plants in several ways. Not only do coffee grounds contain macronutrients, but they also contain micronutrients. All of these are essential for healthy growth.
Macronutrients from coffee grounds that your plumeria need are nitrogen, phosphorus and potassium. You’ll see these abbreviated on fertilizer labels as N, P, and K respectively.
Coffee grounds contain calcium, which helps promote sturdy root growth. They also contain magnesium, which helps photosynthesis and encourages healthy foliage. Coffee grounds can also help to improve the structure of the soil by increasing its organic matter content.
Coffee grounds are acidic, so help to create the right environment for your Plumeria plants. This acidity can help to deter pests and diseases by creating an unfriendly environment for them. However, it’s important to note that you should use coffee grounds in moderation. Adding too much can lead to an imbalance of nutrients in the soil. It’s also a good idea to mix the coffee grounds with other organic matter before adding it to the soil. Compost or well-rotted manure are ideal.
Which nutrients are best for Plumeria plants?
Nitrogen (N), phosphorus (P) and potassium (K) are essential nutrients for all plants. Most fertilizers will list them as ingredients in the form of a ratio, known as the NPK ratio. The first number refers to nitrogen, the second refers to phosphorus and the third refers to potassium.
There is a wealth of research that supports the use of fertilizer for Plumeria plants. A study conducted by the University of Hawaii found that fertilizer boosted the growth of Plumerias. The study showed that the best fertilizer for growth had a ratio of 2:2:1. The application rate and amount was important. A low-level and consistent application pattern is best.
In addition to promoting growth and flowers, fertilizing Plumerias can also help to keep the plants healthy. A study conducted by the University of Florida found that fertilizer use was associated with an increased disease resistance. Nitrogen, phosphorus, and potassium helped to increase the plant’s resistance to disease-causing fungi and bacteria.
Get the best results with a fertilizer that has a ratio of two parts nitrogen, two parts phosphorus, and one part potassium.
How to choose a fertilizer for Plumeria
When selecting a fertilizer for plumeria plants you should consider your gardening habits. If you are time poor then a granular or slow-release fertilizer or granular fertilizer is a good option for you. These fertilizers are often made from organic materials such as seaweed or animal manures. For convenience they are concentrated into pellets or granules. All you need to do is follow the dosage instructions on the fertilizer label and apply in early spring and again in early summer.
If you are a more enthusiastic gardener then a water-soluble fertilizer is a better match for you. With liquid fertilizers the nutrients are absorbed by the leaves as well as the roots of the plant. Start by mixing a fertilizer concentrate with about a gallon of water. Then you sprinkle or spray the solution over the plant’s leaves (foliar feeding). You should also allow it to soak into the soil or potting solution underneath.
You can do this as often as every two weeks throughout the peak growing season, depending on the fertilizer you select. The downside is that the nutrient-rich run-off can can cause problems for other plants or waterways if you use too much.
Young plants
A small tree that is still growing needs a general balanced fertilizer. This is so that it establishes a large and healthy root ball and sturdy structure. You shouldn’t encourage lots of flowers at this stage as they come at the expense of the general growth of the plant. Don’t worry, you’ll still get flowers. At this stage it is more important to grow a healthy tree to get the benefit of beautiful flowers for years to come.
Mature plants
If your frangipani is mature and growing in a pot your priority is general plant health and flower production. You don’t want to stimulate too much leaf production and growth. The first time you fertilize in early spring you should use a fertilizer with the 2:2:1 ratio. This helps the plant to put on new leaf growth and gives it a boost coming out of the winter dormancy.
After that use a fertilizer that targets flower production. Flowers need lots of phosphorus to form. So, to promote stunning flowers and fragrant plants you should switch to a high phosphorus fertilizer in late spring and summer. It can be a specific Plumeria blend or any other blend that is labelled as promoting flowers. Look for a high middle number, indicating lots of phosphorus. For flowers, the best plumeria fertilizer should have a NPK ratio of 1:5:1.
The best plumeria fertilizer for flowers should have a NPK ratio of 1:5:1.
Plumeria care and growing conditions
Plumeria plants are drought- and salt-tolerant and can be easily propagated via cuttings. They thrive in full sun, with at least 6-8 hours of direct sunlight. A well drained soil is best but they can tolerate dryness. Like all flowering plants they need regular watering during the growing season.
Plumeria are very sensitive to frost so can only grow outdoors in tropical, subtropical and warm temperate regions. In colder regions they can grow as a container plant that lives outdoors in the warmer months. Move them indoors while they are dormant over winter. During this time they don’t need water or light. If you don’t have a greenhouse they can safely be kept in a garden shed or garage. Just make sure that they aren’t exposed to freezing temperatures.
If you are growing Plumeria in a greenhouse a red-flowering variety might be the best option for you. Research that the red-flowering variety produces the largest flowers when grown in greenhouses. They also had the longest flowering period1.
How to propagate Plumeria
Plumeria is easily propagated using stem cuttings. The cutting should be at least 10 cm/4 in long but you’ll get better results with a cutting that is longer, about 25 cm/10 in long2. Allow the cut end to form a callus, which takes 2 days-2 weeks. Then dip it in a rooting hormone powder or gel and plant into a pot of free-draining potting soil, at least 4 cm (1.5 in) deep.
Roots will start to form in 4 weeks and a root system should be well established within 8-12 weeks. Longer, stronger roots form on long cuttings by propagating them at higher temperatures (25-31 oC or 77-87 oF). Keep them as warm as you can in the first few weeks. You can even use a heating mat if you are in a cool area. The rooted cutting can be planted out when it shows signs of new foliage growth.
If you are using a fertilizer for young plants grown from cutting a liquid fertilizer is a good choice. However, it should be mixed at or diluted to half strength. Consider using a seaweed extract while the plant is getting established. Then use fertilizer to promote growth. Use seaweed extract for the first month after repotting to help prevent transplant shock.
Plumeria pests and diseases
Plumeria plants are susceptible to several pests and diseases, including:
- Mealybugs: These small, white insects can infest the leaves and stems of plumeria plants, causing them to yellow and wilt.
- Scale insects: Scale insects can also attack the leaves and stems of plumeria plants, causing them to turn yellow and become stunted.
- Root rot: This fungal disease can occur when the soil is too moist or the drainage is poor. Symptoms include wilting leaves and a soft, brown rot at the base of the stem.
- Bacterial blight: This disease can cause the leaves to turn yellow and drop off. The stem may also become discolored and have a slimy texture.
- Powdery mildew: This fungal disease can cause a white, powdery growth on the leaves and stems of plumeria plants.
It is important to keep an eye on the health of your plumeria plants, and to address any issues promptly to prevent them from spreading.
Keeping your plumeria plants healthy and stress-free is the best way to prevent pests and diseases. Stressed plants emit chemical signals that attract pests. This lets the pests such as mealy bugs and scale know that the plant’s natural defenses are weaker than usual. The pest targets that plant knowing that it has the best chance of success.
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References
- Xue, Y., Li, J., Zhou, G., & Shang, A. (2016). Comparison on adaptability of two cultivars of Plumeria rubra L. cv. Acutifolia to northern greenhouse. Journal of Southern Agriculture, 47(5), 690-693.
2. Caruso, S., & Iapichino, G. (2014). Basal heat improves adventitious root quality in Plumeria (Plumeria rubra L.) stem cuttings of different sizes. Journal of Applied Horticulture, 17, 22-25. DOI: https://doi.org/10.37855/jah.2015.v17i01.05
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