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Feijoa Tree Fertiliser Guide: Understanding Growth Habits and Nutrient Demands

Feijoa trees (Acca sellowiana), also known as pineapple guava, are robust evergreen fruit trees that produce fragrant blossoms and delicious green fruit. Although they’re often described as low-maintenance, consistent fertilising is essential if you want to maximise fruit yield, growth rate, and tree health in Australian conditions.

Native to highland regions of South America, feijoas are naturally suited to Australia’s temperate and coastal zones, including Sydney and parts of Victoria and Queensland. While they tolerate periods of drought and light frost, nutrient-poor soils will lead to slow growth, minimal flowering, or even complete fruit failure. To support a healthy, productive tree, it’s critical to understand what nutrients feijoas need and how they use them throughout the year.

How Feijoa Trees Grow

Feijoa trees typically reach 2 to 4 metres in height and spread, with a dense, bushy habit that makes them ideal for hedging or stand-alone orchard planting. The tree produces thick silver-backed leaves, springtime blossoms with edible petals, and green oval fruit that matures in autumn. Once established, feijoas are reliable croppers, but only if fed well.

The tree’s lifecycle involves three key stages:

Vegetative Growth: Occurs in spring and early summer. This is when leaf and shoot development is most active, and the tree builds energy reserves for flowering.
Flowering and Fruit Set: Begins in late spring or early summer, with flowering lasting 4–6 weeks. Proper nutrition is vital for full bloom and successful pollination.
Fruit Development: Occurs through summer and early autumn, when potassium and calcium become essential for fruit size, flavour, and skin quality.

Each stage places a different demand on the tree’s nutrient needs, which is why a one-size-fits-all fertiliser strategy is rarely effective.

Nutritional Needs of Feijoa Trees

Feijoas are moderate feeders. They don’t need extremely high nutrient levels, but they do require the right balance of key macronutrients—particularly during flowering and fruiting stages. The three primary macronutrients (N-P-K) serve different purposes:

Nitrogen (N): Feeds leafy growth and supports the formation of new branches. Essential in early spring, but excessive nitrogen in summer can reduce fruit sweetness.
Phosphorus (P): Needed in smaller quantities. It supports strong root systems and is important during flower initiation. However, too much phosphorus can block micronutrient uptake in feijoas.
Potassium (K): The most important nutrient for fruit production. Potassium regulates sugar movement, improves taste, and helps maintain firm, well-formed fruit.

Secondary nutrients like magnesium, calcium, and sulfur play equally vital roles. Magnesium prevents leaf yellowing and supports chlorophyll production. Calcium is critical for firm fruit texture and long shelf life. Boron and zinc, two important trace elements, are required for proper flowering and fruit set.

How Soil Type Affects Fertiliser Needs

The type of soil your feijoa is growing in has a big impact on how you should fertilise it. In sandy or free-draining soils, nutrients are quickly washed away with rainfall or irrigation. This means fertilisers need to be applied more frequently in lighter soils to avoid deficiencies.

In heavier clay soils, nutrients are retained longer but may become locked up if the pH is too high or too low. A pH of 5.5 to 6.5 is ideal for feijoas. Regular mulching and soil testing every few years is recommended to correct imbalances early.

Feeding Feijoas in the First Year

In the first 12 months, feijoas focus on root and canopy establishment. This is the stage when nitrogen is most important. A balanced fertiliser applied monthly from early spring through late summer will help the tree grow faster and establish a strong framework. Watering the tree after fertiliser application ensures nutrients move into the root zone effectively.

Avoid high-phosphorus starter fertilisers unless a soil test confirms low P levels. Excess phosphorus can interfere with calcium uptake, leading to weak growth and poor fruiting down the track.

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Seasonal Fertiliser Schedule for Feijoa Trees in Australian Climates

Feijoa trees thrive when their nutrient intake is aligned with the natural rhythm of their growth. A seasonally adjusted fertiliser plan ensures that the tree receives the right elements at the right time—helping it grow foliage in spring, flower in summer, and produce large, flavourful fruit in autumn.

In Australia, the growing cycle of feijoas spans from early spring through late autumn. Unlike citrus or stone fruit trees that rely heavily on winter chilling, feijoas are subtropical-adapted and benefit from a longer feeding window. Applying fertiliser too early or too late can cause imbalances in leaf-to-fruit ratio, poor flowering, or even fruit drop.

Spring (September to November)

Spring is the most critical fertilising season for feijoa trees. As the weather warms and daylight hours increase, trees shift from dormancy into active growth. This is when they need a balanced fertiliser with a moderate nitrogen content to support leaf flush and stem elongation.

Start feeding in early September. For younger trees, apply a granular or liquid fertiliser every 3–4 weeks through to late November. Mature trees also benefit from a mid-season top-up. Nitrogen is especially important during this phase, but a balanced NPK formula ensures root development is not neglected. Avoid high-phosphorus fertilisers unless a soil test indicates a deficiency.

Foliar feeding can also be helpful in early spring, especially if leaf colour is pale or growth appears sluggish. Apply on cool, overcast mornings to reduce evaporation and maximise uptake.

Summer (December to February)

Feijoas flower in early to mid-summer, producing showy red and white blossoms that attract pollinators. Once pollinated, small green fruits begin to form. During this period, shift to a fertiliser with a higher potassium content to promote flower development and encourage fruit set.

Fertilise in early December, then again in mid to late January. Liquid applications every 2–3 weeks can be especially effective in sandy or fast-draining soils. Potassium is essential for cell development and sugar transport within the plant—deficiencies at this stage can result in poor fruit set or premature drop.

In hot inland regions or during periods of drought, apply fertiliser in the late afternoon and water thoroughly to prevent burn. Maintain an even moisture level to ensure consistent nutrient uptake.

Autumn (March to May)

Fruit growth accelerates during early autumn. By March, most feijoa fruit are expanding and storing sugars. A fertiliser high in potassium and calcium helps support fruit firmness, sweetness, and skin thickness—qualities that are critical for flavour and transport.

Apply one final round of fertiliser in March or early April. At this point, it’s important to minimise nitrogen levels to avoid forcing vegetative growth at the expense of fruit maturity. This late-season feed supports fruit finish and helps prepare the tree for winter dormancy.

In cooler regions, avoid fertilising after late April, as new growth may be vulnerable to frost damage. Instead, mulch with organic matter to insulate the roots and enrich the soil slowly over winter.

Winter (June to August)

Feijoa trees enter a semi-dormant phase during the winter months. No fertiliser is required during this time. However, it’s a good season for applying compost, aged manure, or mulch to improve soil structure and moisture retention for the next growing cycle.

Refrain from using high-nitrogen fertilisers during winter, as this can trigger untimely growth that is more susceptible to wind or frost damage. Instead, focus on water management, pruning (late winter), and soil pH balancing if needed.

How Often Should You Fertilise Feijoa Trees?

The frequency of application depends on the fertiliser type (liquid vs granular), soil structure, and plant maturity. A general guide is as follows:

Young trees (0–2 years): Light fertiliser every 3–4 weeks in spring and summer
Mature trees (3+ years): Fertilise every 4–6 weeks during the growing season
Potted feijoas: Use diluted liquid fertiliser every 2 weeks

Always apply fertiliser around the drip line of the tree, not at the base. This targets the active root zone and ensures efficient nutrient uptake. Avoid fertilising dry soil, as this can cause root burn. Water before and after each feed for best results.

Fertilising Feijoa Trees: Common Mistakes, Nutrient Deficiencies, and the Right NPK Ratio

Even with the best intentions, fertilising feijoa trees can go wrong when nutrients are over-applied, poorly timed, or imbalanced. Understanding common fertiliser mistakes and identifying early signs of nutrient deficiencies is key to unlocking consistent fruit production and healthy tree development year after year.

Mistake #1: Overusing Nitrogen

While nitrogen is essential for healthy foliage, applying too much—especially late in the season—can shift the plant’s energy away from fruiting and toward excessive leaf and branch growth. This can result in lush-looking trees with few or no flowers or fruit. High nitrogen also makes feijoas more prone to fungal disease and fruit drop during dry spells.

To avoid this mistake, apply nitrogen-rich fertiliser only in early spring when vegetative growth is desirable. By mid-summer, nitrogen should be reduced and potassium increased to direct the tree’s energy toward flowering and fruit development.

Mistake #2: Ignoring Potassium and Micronutrients

Potassium plays a vital role in fruit formation, flavour development, and stress tolerance. Without enough potassium, feijoa fruit may be small, misshapen, or underdeveloped. You may also see leaf scorch or early yellowing on older foliage. This deficiency is particularly common in sandy soils or in trees that haven’t been fertilised consistently during the flowering period.

Micronutrients like boron, zinc, and magnesium are equally important. For example, boron supports flower development and pollination; without it, fruit set may be minimal. Magnesium helps maintain green leaves and healthy photosynthesis. Deficiencies often appear first as interveinal yellowing on older leaves.

Balanced fertilisers that include both primary and trace elements are essential to prevent these issues, especially in soils with low organic matter or during extended rainy seasons where leaching is common.

Mistake #3: Fertilising at the Wrong Time

Timing is everything when it comes to fertilising feijoa trees. Fertilising too early in winter, when the tree is dormant, can lead to nutrient wastage as uptake is minimal. Conversely, fertilising too late in autumn can trigger new growth that is vulnerable to winter frost damage and doesn’t support fruit ripening.

The most effective timing is aligned with active growth phases. Begin in early spring, feed consistently through summer, and taper off by mid-autumn. Avoid applying fertiliser within six weeks of pruning or transplanting to allow the tree to recover without additional stress.

Mistake #4: Applying Fertiliser Too Close to the Trunk

Fertiliser should always be applied around the drip line of the tree—not at the base of the trunk. The drip line is where feeder roots actively absorb nutrients. Spreading fertiliser directly around the trunk risks damaging the root crown and may reduce uptake efficiency.

For best results, distribute fertiliser in a wide ring around the drip line, then water it in well. Liquid formulations can also be diluted and applied via watering can to ensure even coverage in potted trees or confined planting areas.

Identifying Common Nutrient Deficiency Symptoms

Feijoa trees are generally robust, but poor soil conditions or improper fertilisation can result in nutrient stress. Here are key signs to watch for:

Yellowing between leaf veins (Interveinal chlorosis): Often a sign of magnesium or iron deficiency
Brown leaf tips or edges: May indicate potassium deficiency, especially in hot weather
Reduced flowering or fruit drop: Can result from low boron or excessive nitrogen
Slow growth and small leaves: Suggest possible phosphorus deficiency or overall nutrient imbalance

If symptoms appear, conduct a soil test to confirm pH and nutrient levels before making major changes. In some cases, foliar feeding with trace elements can provide a quick fix while soil amendments take effect.

Choosing the Right NPK Ratio

After considering the tree’s seasonal needs and typical deficiencies, the next step is choosing an appropriate NPK ratio. Ideally, a fertiliser should support early growth without encouraging excessive foliage, then gradually shift to fruit-supportive nutrients as the tree matures through the season.

A balanced NPK ratio like 4-18-38 is ideal for feijoa trees during their peak fruiting phase. This formulation provides moderate nitrogen for controlled growth, high potassium for strong fruiting, and sufficient phosphorus to maintain healthy roots. The elevated potassium content supports sugar transport and improves fruit quality while helping the tree cope with environmental stress.

This type of nutrient profile is especially effective for feijoas in sandy soils, coastal conditions, or high-yield backyard orchards where fruit consistency matters. When applied at the correct time and rate, it leads to vigorous flowering, excellent fruit size, and prolonged harvests—hallmarks of a well-fed feijoa tree.

Final Thoughts

Fertilising feijoa trees may seem straightforward, but the details matter. Avoiding common errors like overusing nitrogen, underfeeding potassium, and mistiming applications makes a significant difference in fruit quality and tree health. By observing the tree’s growth stages and deficiency signals, and by using a well-balanced fertiliser like 4-18-38 at the right moment, growers can ensure reliable performance from their feijoas year after year—whether grown for fruit, hedging, or ornamental value.