Citrus Fertilizer: What Your Citrus Trees Need | How & When

Citrus trees produce beautiful, fragrant flowers and delicious fruit, and are naturally heavy feeders.

For this reason, you must fertilize them regularly and properly.

Ripe juicy citrus tree given the right fertilizer

Many home gardeners:

  • Do not give their citrus trees enough fertilizer
  • Fail to fertilize regularly
  • Do not use the right type of fertilizer

In this article, we explain how and when you should fertilize your citrus trees. Read on to learn more.

What Kind Of Fertilizer Is Best?

When you choose a fertilizer, be sure to choose one specially formulated for citrus trees.

Trees grown in the landscape need a balanced 10-10-10 fertilizer.

Those grown in containers need more nitrogen.

For citrus look for a 12-6-5 NPK rating.

All citrus trees will benefit from a heavy nitrogen fertilizer with some phosphorous in it.

How Much Fertilizer Do Citrus Trees Need?

The size and age of your tree will determine how much fertilizer you should give it.

You must fertilize your growing citrus tree correctly for its age.

In young citrus trees, fertilizer stimulates the growth of branches, leaves, and helps grow a more stable root system.

In mature fruit trees, it replenishes nutrients used in fruit production and new plant growth.

How To Fertilize Young Citrus Trees

Fertilize young trees lightly and often throughout the entire growing season. This includes:

  • Lemon trees (Meyer Lemon too)
  • Kumquats
  • Lime trees
  • Calamondin oranges
  • Grapefruit

Organic fertilizer should be applied in a circle measuring 3’ feet around the drip line of the tree.

In places with humid climates, such as Florida, you should start fertilizing your new trees very early in the growing season.

The buds will begin to swell early in February, and you should give your young trees their first dose of fertilizer then.

In the first year, you should use about half a pound of 10-10-10 fertilizer specifically prepared to grow citrus fruit trees.

Repeat the application every six weeks throughout the spring and summer and until October.

In your tree’s second year, start feeding early in the growing season, but provide a little bit more fertilizer.

In the second year, your tree will need a pound of specially prepared citrus fertilizer.

Extend the period between feedings to seven weeks, and continue through October.

In your tree’s third-year, you should again start fertilizing early in the growing season.

Once again, you will double the amount of fertilizer and extend the time interval.

Feed 2 pounds every nine weeks throughout the spring and summer and into October.

Yellowing or pale green foliage with bright green veins is a sign of magnesium, iron or zinc deficiencies.

How To Fertilize Fully Mature Citrus Trees

In mature trees, you must fertilize to replace nutrients used when the fruit is produced.

Additionally, your mature tree naturally needs nutrition to help it grow and thrive.

When your tree passes the three-year mark, reduce fertilizing to 4 to 5 times annually.

Apply the fertilizer directly beneath the canopy of the tree.

Extend fertilizer to the edge of the canopy or even a bit beyond.

When your trees are well established, having been planted for a full three years, reduce the number of times per year you fertilize to three.

You should fertilize once in February, again in May and finally in October.

You’ll need to calculate the amount of fertilizer to give each tree.

To do this, you must keep track of how old the tree is.

Mature trees need a pound of fertilizer for every year of age.

This means if your tree is four years old, it will need 4 pounds of fertilizer in February, again in May and again in October.

When & How Should Citrus Trees Be Fertilized?

As with most fruiting trees, citrus trees need to be fertilized in the early springtime before the first blooms appear.

Granular fertilizer should be sown evenly over the soil beneath the tree to provide the best micronutrients.

Foliar sprays are available containing these micronutrients.

Don’t place it in a mound against the base of the tree.

If you are unable to fertilizing in early spring, hold off until the fruit appears and is approximately pea-sized.

Also, wait until you see fruits appear before you prune.

This should be around May 15.

Follow These Steps to Apply Fertilizer Correctly For Citrus Trees In The Landscape

Begin by scattering the fertilizer evenly over the ground beneath the tree.

Be sure to avoid contact with the trunk of the tree.

After fertilizer application, water your trees very thoroughly.

This is of great importance in areas having a dry climate.

Follow These Steps to Feed Citrus Trees Kept in Containers

When you feed your citrus trees properly, they will naturally produce more fruit.

If you live in a warm climate, grow your trees right in your yard.

In cooler climates, it is possible to have great success with citrus trees kept in containers.

Container citrus trees should only receive fertilizer for part of the growing season.

Begin early in the springtime and cease fertilizing in the middle of the summer.

This lets your tree get ready for the winter months.

With citrus trees in containers, you may wish to use slow-release fertilizer one time yearly.

In this case, you would apply it only early in the spring and not again.

If you are using a liquid fertilizer plant food, you’ll need to feed up to every other week from early springtime through mid-summer.

For container plants, you’ll need to find a fertilizer prepared especially for potted citrus.

It should have twice as much nitrogen as it does phosphorus.

For example, a good NPK rating would be 12 – 6 – 6.

The exception is grapefruit, hardy in USDA zones 9 through 11, which requires half this much fertilizer once it is mature.

Follow Best Practices Right From The Start For Thriving Citrus Trees

When you purchase citrus trees, you’ll get the best results if you buy only from certified nurseries.

This will help ensure you’re getting trees unlikely to spread citrus diseases and have been properly cared for since germination.

  • Don’t overdo it when you purchase citrus trees.
  • Remember they need at least 15’ feet of space all the way around.
  • Don’t plant citrus trees very close to existing structures including buildings, drain fields, septic tanks, and power lines.

In addition to fertilizing, provide the right conditions for your citrus trees to thrive.

  • Citrus trees can tolerate partial shade, but they naturally produce more and do better with full sunlight.
  • Keep your citrus trees well-watered until they are fully established.
  • Keep an eye on them and remove any suckers emerging from the base.
  • If you leave them, they will interfere with the development of the tree.
  • Once your citrus trees are mature, they will not need regular pruning.
  • Even so, you’ll need to remove any damaged or diseased limbs and branches.
  • Pruning excessively reduces the production of fruit.

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