By Tex Norwood
My method for starting plumeria seeds uses 2-inch-by-3-inch growing plugs, a plug tray, and a flat tray that holds water. I grow the seedlings outdoors in full sun from the beginning, supply nutrients through the tray water and a foliar spray, and transplant the entire rooted plug into a pot.
In 2024, a seedling grown from Majestic seed bloomed at about seven months. I planted that batch in March. Majestic was the seed parent; the pollen parent was unknown.
That result does not mean every seedling grown this way will bloom in seven months. What I want to share is the method behind that result, the conditions during that growing season, and why I believe this approach supports steady growth.
What I used
For this batch, I used:
- Plumeria seeds from Majestic, with an unknown pollen parent.
- Ordinary 3% hydrogen peroxide and well water for the overnight seed soak.
- 2-inch-by-3-inch growing plugs in a matching plug tray.
- A solid flat tray beneath the plug tray to hold water.
- Excalibur BOOST in the tray water.
- BioBlast 7-7-7 as a foliar spray.
- One-gallon pots for transplanting at six weeks.
- Excalibur BOOST again at transplanting.
| Stage | Product | Amount I used |
|---|---|---|
| Overnight seed soak | 3% hydrogen peroxide | 2 fluid ounces added to 1 gallon of well water |
| Plug tray | Excalibur BOOST | 1 tablespoon per gallon of tray water, with the granules left in the tray |
| Foliar feeding | BioBlast 7-7-7 | 1 tablespoon per gallon of spray water, every two weeks until transplanting |
| Transplanting at six weeks | Excalibur BOOST | 2 tablespoons per one-gallon pot |
These are the amounts I used in this batch. When repeating the method, check the formulation and directions on your current product labels. A tablespoon measures volume, and different fertilizer formulations should not be treated as interchangeable.
Step 1 — Label the seeds before starting
Keep the seed parent, planting date, and seedling identity together from the beginning.
For this batch, the parentage description is Majestic × unknown. These seedlings are offspring of Majestic, not copies of Majestic, and should not simply be labeled as that cultivar.
Give each seedling an individual identifier when practical. That becomes especially valuable when one flowers unusually early or produces a flower worth evaluating further.
The Majestic record on Plumeria Database provides information about the parent cultivar. Its descriptions and photographs should not be mistaken for records of this particular seedling.
Step 2 — Soak the seeds overnight
I soaked these seeds overnight in:
2 fluid ounces of 3% hydrogen peroxide added to 1 gallon of well water.
For a smaller batch, the same ratio is one-half fluid ounce of 3% peroxide added to one quart of water.
The starting peroxide strength matters. This recipe uses ordinary 3% hydrogen peroxide, not a stronger concentrate.
The water hydrates the seeds before planting. Peroxide can affect organisms on the seed surface, but its activity depends on concentration, exposure time, and water conditions. I cannot separate its contribution from everything else I did with this batch.
Prepare the growing tray before the soak ends so the seeds can be planted promptly. Keep the seed-soak solution separate from the water used to grow the seedlings.
This soak is part of my reported method, not a reason to keep adding peroxide to the growing tray. The Care Guide’s peroxide discussion explains why concentration and exposure deserve attention.
Step 3 — Set up the plugs and water tray
Place the growing plugs in their matching plug tray, then place that tray inside a flat tray without drainage holes.
The inner tray supports the plugs. The outer tray holds the water.
Use a level surface so one end does not remain much deeper than the other. Add water and allow the plugs to wet evenly. Check plugs near the edges as well as those in the center.
The plugs provide a stable place for the seed and developing roots. Later, I can move the rooted plug into a pot without pulling the seedling out of loose medium.
Step 4 — Add Excalibur BOOST to the tray water
For this batch, I used:
1 tablespoon of Excalibur BOOST per gallon of tray water.
I left the granules in the tray.
Measure the amount against the actual water added, not the nominal size of the tray.
I described this as dissolving BOOST in the water, but there is a useful distinction: nutrients can enter the water while some granules or coating material remain. Remaining granules do not tell you exactly how much nutrition has been released or how much is still available.
That matters when refilling. Adding water does not automatically mean another full fertilizer dose is needed. Keep track of the original charge, subsequent additions, and what happens to the remaining granules during water changes.
BOOST descriptions and analyses differ across published product pages, so use the label on the product in hand. My tray application records how I used it; dry-pot directions alone do not establish the nutrient concentration produced in a reservoir. See Florida Colors’ BOOST information.
Step 5 — Plant the seeds in the moist plugs
Open a narrow slit in each plug and place one seed in it, with the thicker seed body in contact with the moist plug and the papery wing pointing upward.
Make the opening fit the seed rather than forcing a small seed unnecessarily deep into the plug.
Gently close the plug around it to maintain contact without crushing the seed.
The objective is consistent moisture around the seed while allowing the emerging seedling to grow above the plug.
Step 6 — Place the tray outdoors in full sun
I placed this batch outside in full sun from the beginning.
These seedlings developed under that exposure rather than being raised indoors and suddenly moved into strong sunlight.
Once leaves emerge, light provides the energy for photosynthesis. Fertilizer supplies mineral nutrients; the leaves use light to manufacture the carbohydrates that support growth.
Full sun also heats the tray and increases water use. Watch the water temperature and plug moisture, especially during hot or windy weather.
A grower working in a different climate may need to protect the reservoir from excessive heat. Seedlings already accustomed to shade or indoor conditions should be acclimated gradually.
The weather during this growing season
I planted in March 2024, so the seedlings developed through South Florida’s spring and summer. Historical weather records help describe that growing season.
The temperatures below are regional weather-station observations. They are not measurements from my trays, plugs, or nursery bench. The monthly means include daytime and nighttime conditions; they are not average daytime highs.
| Period | Regional observation | Source |
|---|---|---|
| March 2024 | Miami’s monthly mean temperature was 75.8°F, 2.7°F above normal. Rainfall totaled 4.78 inches, 2.32 inches above normal. | Florida Climate Center — March 2024 |
| April 2024 | Miami’s monthly mean temperature was 76.3°F, 0.4°F below normal. | Florida Climate Center — April 2024 |
| May and summer 2024 | Homestead General Airport reached 100°F on May 19. The National Weather Service reported a record-hot May at the four main South Florida climate stations and a hotter-than-normal summer. | NWS — South Florida 2024 Weather Summary |
| October 2024 | Miami’s monthly mean temperature was 80.2°F, 0.1°F above normal. October is approximately seven months after March, not a separately verified first-bloom date for this seedling. | Florida Climate Center — October 2024 |
Rainfall also changed during the season. The National Weather Service described a very dry April and May, followed by a wet June, drier July conditions, and a wetter-than-normal period from August into mid-October. Those regional changes provide context for why water management needed attention throughout the growing season. They do not establish how much rain entered my particular trays. NWS 2024 summary.
My interpretation is that the long, warm growing season helped support continued development alongside light, nutrition, and healthy roots. Weather records alone cannot establish why this seedling flowered at seven months.
They also should not be used as target temperatures for the reservoir. Warm water holds less dissolved oxygen than cool water, so more heat is not automatically better for roots. The USGS explanation of dissolved oxygen and water supports that distinction.
For growers who want more local historical observations, the University of Florida’s FAWN reporting system includes a Homestead station. Those observations are another source of environmental context, rather than a substitute for measuring conditions in the growing tray.
Step 7 — Maintain the water and inspect the seedlings
I changed the tray water as needed.
Rather than turning that phrase into a fixed calendar interval, look at what is happening:
- Is the water level still supplying moisture to the plugs?
- Are the emerging stems above the free water?
- Is the water becoming unusually warm, cloudy, or foul smelling?
- Is debris collecting in the reservoir?
- Are roots developing and leaves expanding?
Keep a record of water and fertilizer additions. When changing water, also record whether remaining BOOST granules are retained or removed. Otherwise, it becomes difficult to know what fertilizer charge is still present.
Water availability is only part of root health. Roots also need oxygen. A plug standing in water does not automatically maintain adequate air throughout its entire volume.
My earlier plug-and-water article describes reducing the water level after germination. When adapting the system, mark the working level on the actual tray and check that the plugs continue to wick moisture without submerging the seedling crowns.
Step 8 — Foliar feed with BioBlast every two weeks
Until transplanting, I sprayed the seedlings every two weeks with:
1 tablespoon of BioBlast 7-7-7 per gallon of water.
This was a foliar application, separate from the BOOST in the tray water.
BioBlast supplies nitrogen, phosphorus, and potassium, along with other listed ingredients. Foliar feeding provides an additional route for nutrient uptake while roots continue to obtain nutrients from their growing environment.
Apply foliar sprays during a cooler part of the day, with time for foliage to dry. Avoid allowing substantial spray runoff to collect in the reservoir, where it would become an unmeasured addition to the root-zone feed.
The older starter-kit instructions include a different early seedling rate. The tablespoon-per-gallon amount above is the rate I confirmed for this 2024 batch. More about the product is available in Why Bioblast.
Step 9 — Transplant the rooted plugs at six weeks
I transplanted this batch into one-gallon pots at six weeks.
For another batch, use six weeks as a reference point and inspect the plants. Look for developing roots and continuing growth. Do not wait until roots from neighboring plugs become heavily tangled simply to reach a particular date.
Prepare the receiving pot and planting hole before lifting the plug. Support the plug from underneath and move it with its roots intact. Avoid pulling on the stem or breaking the plug apart.
Settle the surrounding potting mix against the plug without packing it tightly. Maintain the seedling’s existing crown level rather than burying a length of stem.
The benefit of the plug continues here: the roots move with their growing medium, reducing handling and disruption.
Step 10 — Apply BOOST in the one-gallon pots
At transplanting, I used:
2 tablespoons of Excalibur BOOST per one-gallon pot.
This is a per-pot application, not a mixing rate per gallon of irrigation water.
Distribute fertilizer according to the current label, avoid a concentrated pile against the stem, and water the pot thoroughly so the mix settles and excess water drains.
Once the seedling is in a pot, manage it as a container-grown plant. Keeping the pot standing in water does not necessarily duplicate the conditions of the original plug tray.
Check both the original plug and the surrounding mix. They can hold and lose water differently.
Why this method can work
The advantage is continuity.
A small plug can dry quickly. A reservoir gives it access to water between checks, helping reduce repeated drying that could interrupt growth.
The plug also supports the developing root system. Moving it intact can reduce disturbance when the seedling goes into a pot.
BOOST provides mineral nutrients through the root environment. BioBlast adds foliar nutrition. Full sun provides the light needed to use that water and nutrition for growth, while the warm growing season provides an extended opportunity for development.
These parts work together only when the roots remain healthy. Excessive heat, insufficient oxygen, accumulating fertilizer salts, or disease can undermine the system.
Research on propagation substrates supports the importance of balancing water and air, although it did not test these particular FCN plugs or my seedlings. See Water and Air Relations in Propagation Substrates.
What the seven-month bloom tells me
The Majestic seedling’s early bloom is a valuable result, but I would not give one product—or the weather alone—all the credit.
My interpretation is that the growing system helped the seedling maintain development with fewer interruptions. Its genetics also mattered. A seedling must become capable of flowering; additional fertilizer alone cannot guarantee that transition.
The result is worth recording and trying to reproduce. It is not a promise that every Majestic seedling, or every seedling grown in a water tray, will flower at the same age.
My goal is to give each seedling the opportunity to develop well: keep the roots functioning, provide appropriate nutrition and light, transplant without unnecessary damage, and document what happens. The first flower then becomes part of a growing record that can help improve the next batch.