Excalibur plumeria fertilizer is a balanced, coated slow release granule made for plumeria and sold by Florida Colors Nursery. The main version is rated at 11-11-13. It is meant to feed a pot for about nine months from one dose.
It suits growers who want a set and forget feed. It is a poor fit if you want to push blooms with a high phosphorus mix.
This review is based on the maker’s product pages and on what growers have said in public. We have not tested it, so nothing here is a lab result or a bloom count. For the wider field, see our guide to the best plumeria fertilizers.
What Excalibur plumeria fertilizer is
According to the maker, Excalibur is a granular, multi coated controlled release fertilizer. Each granule has a polymer shell. Moisture soaks through the shell, nutrients dissolve inside, and they leak out slowly.
The maker says the release rate was set at 86 F, so the coating responds to water and warmth.
It comes in three versions, and the names are easy to mix up.
| Version | Analysis (NPK) | Stated release |
|---|---|---|
| Excalibur IX | 11-11-13 plus micronutrients | About 9 months |
| Excalibur VI | 11-11-14 plus micronutrients | About 6 months |
| Excalibur Boost | 11-12-13 plus micronutrients | About 3 months |
Both main versions list boron among the extra nutrients. The maker’s pages do not publish a full guaranteed analysis or an ingredient list. So we cannot name the nitrogen sources or the exact iron and magnesium levels in current bags.
An older Plumeria Society of America newsletter listed the nine month blend with 0.48 percent iron and 0.36 percent magnesium. Formulas change, so check the label on your bag.
Sizes and how much to use
The nursery sells the 9 month and 6 month versions in 4 lb resealable bags. Multi bag options run to 8, 12 and 16 lb. The maker says one 4 lb bag holds roughly 120 tablespoons, which is a lot of pots for a small collection.
The maker’s suggested amounts are the same for both main versions.
| Pot or plant size | Suggested amount |
|---|---|
| 4 to 4.5 inch pot | 3/4 tablespoon |
| 6 inch (1 gallon) pot | 1 to 2 tablespoons |
| 8 inch (3 gallon) pot | 3 tablespoons |
| Larger plants | About 1 tablespoon per inch of trunk width at the soil line |
Plumeria are not heavy feeders, and a small pot can be overfed quickly. If you are unsure, start at the low end of each range.
How to apply it
- Water the pot first if the mix is bone dry.
- Sprinkle the dry granules on the surface, keeping them off the stem.
- Scratch them in, or cover them with an inch or two of mix, as the maker advises.
- Water well so the coating starts to work.
- Mark the date on the pot label so you know when the feed is spent.
Growers commonly apply slow release feeds once spring growth is underway. A bare, dormant plant cannot use the nutrients, and a warm spell can still trigger release. Our guide on how and when to fertilize plumeria covers the seasonal timing in more detail.
Apply it once per season, not monthly. Adding more on top of an active dose is the usual way to burn roots and soften stems.
Who Excalibur plumeria fertilizer suits
This fertilizer fits a few kinds of growers well.
- Container growers with many pots who do not want to mix a solution every week. Our page on growing plumeria in containers explains why pots drain nutrients fast.
- People who forget or travel, since one application covers months.
- Growers in long, warm seasons, where a 6 or 9 month release matches the growing window.
- Anyone who wants a balanced feed with micronutrients and does not want to buy several products.
Who should look elsewhere
- Growers in short summers. In a cool climate, a nine month feed may stop before you want it to, or release unevenly. The 6 month version may be the better match.
- Anyone chasing more flowers with a high middle number. A balanced 11-11-13 is not a bloom formula. Our plumeria bloom guide explains what actually drives flowering, and it is mostly sun and maturity.
- Growers who like to adjust. You cannot pull granules out once they are watered in. That means no dialing back after heavy rain or a cold snap.
- Plants that are sick, rootless or newly rooted. Wait until they are growing well, as set out in our guide to saving a dying plumeria.
Pros and cons
Pros
- One application can cover a long stretch of the season.
- Balanced analysis with micronutrients and added boron, according to the maker.
- Clear dose guide by pot size.
- Made and sold specifically for plumeria.
Cons
- Release speed depends on heat and water, so it is hard to predict exactly.
- No published ingredient list or guaranteed analysis on the product pages we checked.
- Cannot be reversed once applied.
- Sold mainly through one nursery, so shipping and availability matter.
Excalibur vs water soluble bloom feeds and Nelson
A water soluble bloom feed, such as Schultz Bloom Plus, works the opposite way. You mix it and water it in, and the plant gets the dose within days. You choose the strength and timing, and you can stop at once if a plant looks stressed.
The cost of that control is effort, since you must repeat it all season.
Nelson plumeria food is a different kind of product again. It is sold as a high phosphorus plant food, so it leans toward blooms while Excalibur stays balanced. Many growers pair a slow release base with an occasional bloom feed.
That is a choice, not a rule.
In short, pick Excalibur for convenience, a water soluble feed for control, and Nelson for a phosphorus heavy approach. A weighing of the pros and cons of each type is in our fertilizer roundup above.
What growers say
Public discussion of this one product is thin. The comments we found are brief and mostly positive. One grower in a plumeria society newsletter reported good results from the nine month version over three years.
She planned to keep using it at repotting.
Detailed complaints are not well documented online. The drawbacks above come from how coated slow release granules work in general, not from a pile of reviews. Be wary of any site that claims to know how well it blooms for you.
The same newsletter noted that high phosphorus feeds were once standard but are not what many growers now recommend. That fits a balanced feed like this one.
Cost of Excalibur plumeria fertilizer over a season
We do not quote prices because they change, and Excalibur plumeria fertilizer is sold in several bag sizes. A single 4 lb bag lasts a long time for a small collection. One dose per season replaces many liquid feedings.
The bulk bags make sense only if you grow dozens of pots.
Shipping can be a bigger part of the cost than the fertilizer itself for a small order. Availability on Amazon varies, so check the search page below and compare it with the nursery.
Using Excalibur plumeria fertilizer with other feeds and soil
If you already use a slow release feed, do not add another on top. Choose one base feed per pot and add a liquid only if you have a specific reason.
Good drainage matters more than any product. A fast, gritty mix, as described in our soil for plumeria guide, lets you water enough to activate the coating. It also keeps the roots from sitting wet.
If you prefer to avoid coated products, our page on homemade plumeria fertilizer covers other options.
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Frequently Asked Questions
How often should I apply Excalibur to plumeria?
Once per season. That means every 9 months for the IX version and every 6 months for the VI version. Do not reapply early because the leaves look pale.
Can I use Excalibur on dormant plumeria?
It is better to wait until the plant is leafing out and the mix is warm. A dormant plant is not taking up nutrients, and the coating can start releasing in warm, wet mix. See our page on plumeria dormancy for what normal looks like.
Is Excalibur a high phosphorus fertilizer?
No. The main versions are balanced at 11-11-13 and 11-11-14. If you want a high phosphorus feed, look at a dedicated bloom product instead.
Can slow release granules burn plumeria roots?
Yes, if you use too much or pile them against the stem. Follow the dose by pot size and keep granules off the trunk.
Which version should I buy, the 6 month or 9 month?
The 9 month version suits long, warm growing seasons. The 6 month version is the safer pick where summers are shorter. It will be spent by the time the plant slows down.