Application amounts
How Much Excalibur Fertilizer to Use
Use pot size as the starting point, then refine by trunk diameter, branch count, root ball, and overall plant size. The current product label and Florida Colors page should always be treated as the final authority.
Purchase links open floridacolorsplumeria.com in a new tab.
The big idea
Pot size gives the starting amount. Plant size fine-tunes it.
Two plumeria in the same pot size can need different amounts. A small newly rooted plant in a 3 gallon pot is not the same as a thick, multi-branched plant filling the same container.
That is why this guide uses three checks: container size, trunk diameter, and how much active top growth the roots are supporting.
Before measuring
- Use level tablespoons, not heaping scoops.
- Feed only actively growing, rooted plants.
- Keep fertilizer away from direct trunk contact.
- Apply dry, cover lightly when practical, and water in well.
Step 1
Start with the pot-size table
| Pot or growing situation | Starting amount | How to refine it |
|---|---|---|
| 4″ to 5″ pot | About 3/4 tablespoon | Use only for rooted, active plants. If the plant is tiny or newly stressed, wait rather than feeding. |
| 6″ pot to 1 gallon | About 1 to 2 tablespoons | Use the lower end for a small plant or one with few branches; use the higher end only when growth is active and roots are established. |
| 3 gallon pot | About 3 tablespoons | This is a common container benchmark. Reduce if the plant is undersized for the pot. |
| 5 gallon pot | About 4 to 6 tablespoons | Choose the low end for a lean plant, recently repotted plant, or limited branching. Use the upper end for a vigorous, well-rooted, multi-branched plant. |
| Larger containers | Use trunk and root-ball judgment | Pot size alone becomes less accurate. Compare trunk diameter, branch count, canopy size, and whether the roots fill the pot. |
| In-ground plumeria | About 1 to 2 tablespoons per inch of trunk diameter | Use the lower end for young or lightly branched trees. Use the higher end only for actively growing, mature, well-rooted, heavily branched trees. |
Florida Colors also notes that larger plants usually have larger root balls. That is why trunk diameter and overall plant size become more useful as the plant gets larger.
Step 2
Use trunk diameter to refine the amount
Measure near the soil line
Use the trunk diameter near the soil line as a plant-size clue. Florida Colors commonly references about 1 tablespoon per 1 inch of trunk diameter, with in-ground plants often considered in the 1 to 2 tablespoon per inch range.
Use the low end for containers
In a pot, roots are limited by soil volume. If the trunk method gives a larger amount than the pot-size table, start with the lower, safer interpretation unless the plant is clearly large and well-rooted.
Add trunks carefully
For a multi-trunk plant, estimate the combined diameter of the main trunks near the soil line, then stay conservative if the plant was recently moved, repotted, or stressed.
Step 3
Let branches and canopy choose the low or high end
Branch count is not a separate fertilizer formula. It is a way to decide whether the plant belongs near the low end, middle, or high end of the pot-size or trunk-diameter range.
- 1 to 2 active branches: use the lower end.
- 3 to 5 active branches: use the middle of the range if the plant is vigorous.
- 6 or more active branches: consider the upper end only if the plant is well-rooted, warm, and actively growing.
- Lots of branches on a stressed or root-limited plant: fix the stress first; do not force growth with more fertilizer.
Examples
Small rooted plant in a 1 gallon pot
Start near 1 tablespoon if the trunk is thin and branching is light. Move toward 2 tablespoons only when roots and growth are active.
Average 3 gallon plumeria
Use the 3 tablespoon starting point when the plant is rooted and active. If the plant is small for the pot, reduce or wait.
Established 5 gallon plant with several branches
Use 4 tablespoons for a moderate plant. Consider 5 to 6 tablespoons only if the plant is vigorous, well-rooted, and filling the container.
In-ground tree with a 3 inch trunk
The trunk rule suggests roughly 3 to 6 tablespoons. Choose the low end for a young or lightly branched tree, and the higher end only for a mature, heavily branched, active tree.
Large pot, small plant
Do not dose by pot size alone. If the root ball does not fill the pot, fertilize by actual plant size or wait.
Recently repotted plant
Use restraint. BOOST may be useful after roots are active, but fertilizer should not be used to force a plant still recovering from transplant stress.
BOOST as a supplement
BOOST is a shorter-release formula used when plumeria need support after rooting, repotting, grafting, transplanting, weather stress, or an establishment setback.
Use BOOST as a side dressing and keep it away from trunk contact. If VI or IX is already in the soil, treat BOOST as a targeted supplement rather than a reason to keep adding more fertilizer.
The Florida Colors link opens floridacolorsplumeria.com in a new tab.
Use less or wait when…
- The plant is dormant or cold.
- The cutting is not rooted.
- The soil is staying wet.
- The trunk is soft or stressed.
- The plant was already fertilized recently.
Related guides
How to apply Excalibur
Read the full application guide for placement, water-in, and timing.
When to feed
Check whether the plant is ready before deciding on amount.
Florida Colors rates
Use current Florida Colors product pages for current labels, formulas, stock, and purchase details.
Fertilizer knowledge base
Watering and moisture
Review watering and root-zone moisture before increasing fertilizer.
Seasonal formula choice
Bottom line
Start with the pot-size table, check trunk diameter, then use branch count and overall tree size to choose the low, middle, or high end. If the plant is stressed, dormant, rootless, or wet, the right amount is usually none yet.