Guava trees are heavy feeders that need a balanced 6-6-6-2 NPK fertilizer applied monthly in their first year, then 3–4 times per year once mature, plus annual micronutrient sprays for best fruit production.
Getting the fertilizer right is the difference between a guava tree that survives and one that loads up with sweet fruit. These tropical trees pull a lot from the soil, and the standard “throw some 10-10-10 on it” advice misses the mark on magnesium and the trace elements guavas actually crave. This guide breaks down the exact ratios, timing, and application steps so you stop guessing and start picking fruit.
The Exact NPK Ratio Guava Trees Need
Guava trees perform best on a fertilizer blend that includes magnesium alongside the main three numbers. The industry standard is 6-6-6-2, which means 6% nitrogen, 6% phosphorus, 6% potassium, and 2% magnesium. This is the ratio most often recommended by the University of Florida’s IFAS Extension and tested by home growers in subtropical climates. A standard 10-10-10 balanced fertilizer also works, but it lacks the magnesium guavas use for chlorophyll production and fruit quality.
Micronutrients matter more for guavas than most fruit trees. Plan to apply foliar sprays containing copper, zinc, manganese, and boron three times per year during the first two growing seasons, then once per year for mature trees. Skip these sprays in winter when the tree is dormant and won’t absorb them.
How Much Fertilizer and How Often
Newly planted guava trees and established trees have completely different feeding schedules. Misting a young tree with adult doses burns the roots; skimping on a mature tree starves the fruit.
First-year trees: Start feeding once new growth appears, roughly one month after planting. Apply 1/4 pound (114 grams) of 6-6-6-2 per tree, scattering it in a wide ring. Repeat every month through the growing season (spring to late summer). Gradually increase the dose so that by the end of the first year, you’re applying 1 pound (455 grams) per feeding.
Mature trees (year two and beyond): Cut back frequency to 3–4 times per year, starting in late winter or early spring and continuing through early summer. Each feeding should be 2 pounds (roughly 1 kg) of 6-6-6-2 per tree. Never exceed a total of 20 pounds per tree in a single year. Stop all fertilizing from late fall through midwinter — feeding during dormancy pushes tender growth that frost kills.
How To Apply Fertilizer The Right Way
The method matters as much as the mix. Guava roots spread wide and shallow, and fertilizer piled at the trunk does nothing but risk burning the bark.
- Measure the ring. Start scattering the fertilizer 1 foot (31 cm) from the trunk — never against it.
- Spread to the drip line. Work the granules evenly outward to the edge of the tree’s canopy, where the feeder roots are most active.
- Rake it in lightly. Scratch the fertilizer into the top inch of soil so it doesn’t wash away in the next rain.
- Water immediately. A thorough soaking right after application carries the nutrients down to the root zone. Without water, granular fertilizer sits on the surface and much of the nitrogen evaporates.
For foliar micronutrient sprays, mix the solution according to the product label and spray both the tops and undersides of leaves and stems. Do this in the early morning or late afternoon — spraying in direct midday heat burns the leaf surface and prevents absorption.
Fertilizer Schedule At A Glance
| Tree Age | Frequency | Dose Per Feeding |
|---|---|---|
| First year (new growth onward) | Every 1 month (or 1–2 months in FL) | Start at 1/4 lb (114 g), finish at 1 lb (455 g) |
| Second year and mature | 3–4 times per year (spring to summer) | 2 lbs (1 kg) per feeding; max 20 lbs/year total |
| Micronutrient spray (first 2 years) | 3 times per year (spring to summer) | Per label dilution |
| Micronutrient spray (mature trees) | 1 time per year | Per label dilution |
| Organic liquid fertilizer | Weekly or every 10–14 days | Half-strength dilution |
| Yellowing tree (nitrogen boost) | Once, when symptoms appear | 100 grams urea scattered per tree |
| Winter feeding | DO NOT FEED | None |
Correcting Soil Problems Before They Hurt the Fruit
Guava trees prefer a soil pH between 5.0 and 7.0. Outside that range, nutrients lock up and the tree shows deficiency symptoms even when fertilizer is present. If your soil runs alkaline (high pH), standard iron sulfate won’t work — the roots can’t absorb it. Use iron chelates instead, which stay available to the tree in alkaline conditions. For neutral to acidic soil (pH 4.5–7), 1–3 pounds of iron sulfate per tree corrects iron chlorosis (yellow leaves with green veins). If you’re buying a complete fertilizer blend for your guava trees, check our tested product roundup of top-rated guava tree fertilizers to match the right formula to your soil type.
Mistakes That Starve or Kill a Guava Tree
The most common errors home growers make with guava fertilizer come down to timing, placement, and reading the tree wrong. Overwatering is the biggest non-fertilizer killer — saturated soil rots the roots and the tree can’t uptake anything you feed it. Let the top few inches dry between waterings. Trunk contact with fertilizer burns the bark and can kill young trees; always keep that 1-foot buffer. Feeding in late fall or winter pushes tender new shoots that die at the first frost, setting the tree back a whole season. For bearing trees, too much phosphorus actually reduces fruit sweetness by crowding out potassium — that’s why the fruiting-stage ratio drops phosphorus to 2–4% and raises potassium to 9–15%. If you’re using organic liquid fertilizer, always dilute it to half strength — full-strength liquids can overload the roots and cause leaf tip burn.
Final Feeding Checklist for a Heavy Guava Harvest
- Use a 6-6-6-2 or 10-10-10 base fertilizer; switch to high-potassium (9–15% K) after fruiting begins.
- Scatter 1 foot from the trunk, spread to the drip line, rake in, and water immediately.
- Feed monthly in year one; 3–4 times per year in year two and beyond.
- Apply micronutrient sprays (copper, zinc, manganese, boron) 3 times per year for young trees, 1 time per year for mature trees.
- Stop all fertilizing from late fall through midwinter.
- Correct high-pH soil with iron chelates, not iron sulfate.
- Never let fertilizer touch the trunk, and never feed a waterlogged tree.
FAQs
Can I use a general fruit tree fertilizer on my guava?
Yes, as long as the NPK ratio is balanced and you supplement magnesium and micronutrients. Many standard fruit tree blends lack the 2% magnesium guavas need, and almost none include copper or zinc sprays — you’ll need to add those separately through foliar applications for full fruit production.
How do I know if my guava tree needs more potassium?
Look for fruit that stays small, ripens unevenly, or tastes bland even when fully colored. Potassium drives sugar transport and fruit sizing in guavas. Leaf edges that turn brown and curl inward are another potassium-deficiency signal, especially on bearing trees.
Is cow manure good for guava trees?
Aged cow manure works well as a soil amendment when mixed in one month before planting, but it should not replace a balanced fertilizer during the growing season. Manure releases nutrients slowly and lacks the precise ratio of nitrogen and potassium guavas need for fruiting.
Why are my guava tree leaves turning yellow after fertilizing?
Yellowing right after feeding usually points to overwatering or fertilizer burn from too-close application. If the granules sat within 1 foot of the trunk, flush the soil with water. If the soil stays soggy, let it dry out before watering again — saturated roots can’t absorb the nutrients you just added.
Should I fertilize a guava tree in a container differently?
Container guavas need more frequent feeding with a weaker dose because nutrients wash out faster during watering. Use a half-strength balanced liquid fertilizer every two weeks during the growing season, and stop entirely in winter. Ensure the pot drains freely — salt buildup from fertilizer is a common killer of potted guavas.
References & Sources
- Gardening Know How. “Feeding Guava Trees.” Covers primary NPK ratios, seasonal feeding schedule, and step-by-step scattering method for home growers.
- UF/IFAS Extension. “Guava Growing in the Florida Home Landscape.” Official research-based guidelines on fertilizer ratios, dosages per tree age, iron correction, and micronutrient spray schedules.
- UC Master Gardeners (San Luis Obispo). “Guava Trees.” Regional feeding advice including 6-6-6-2 ratio, dormancy feeding restrictions, and pruning timing.