Palm Tree Fertilization

palm trees under blue sky

Palm trees can be found across a wide, arcing swath of the U.S. from Virginia to Florida, west to California and north to Washington, and across the border in British Columbia. Palms mostly grow in hardiness Zone 8 and above, and will also successfully grow in microclimates, even in Zone 7.

Palm trees Thrive in Nutrient-rich Soil

Palm trees require a wide variety of essential nutrients for them to remain healthy, particularly: nitrogen (N); phosphorus (P); potassium (K); and, magnesium (Mg). Palm trees also require a number of micronutrients, including: boron (B); calcium (Ca); copper (Cu); iron (Fe); manganese (Mn); and, zinc (Zn).

The wide variety of nutrients palm trees require and the poor, nutrient-deficient sandy soil in which they often grow, make a routine fertilization program very important. Nutrient deficiencies can cause a wide range of diseases in palm trees, but with proper fertilization and care, these diseases can be avoided. Check with your local university extension to learn more about the common nutrient deficiencies in your area and to have your soil tested for specific nutrient deficiencies in your soil.

In addition to not providing the correct nutrients, it’s also important that the correct amount of nutrients is applied—too much or the incorrect proportions of nutrients can be more detrimental to palm trees than not fertilizing at all. Turf fertilizers, for example, should never be applied to palms or used near them. Soil conditions and pH level are also considerations.

Slow-release Fertilizers are Best for Palm Trees

Milorganite is a slow-release fertilizer that works for up to ten weeks and its organic matter helps condition the soil to better hold moisture. Quick-release, artificially coated fertilizers release nutrients too quickly for palms to fully benefit from them and can easily wash away after only a few rains.

Fertilizing Palm Trees with Milorganite®

Milorganite, with the addition of potassium and micronutrients, can be the basis of a complete palm tree fertilization program. Palm trees should be fertilized four times, evenly scheduled throughout the growing season in your area of the country, which may be as early as March and as late as October. Apply 5–10 lbs. of Milorganite by broadcasting it evenly under the entire canopy of the palm. Stay two feet from the tender trunk of the palm tree.

Fertilizing Palm Trees

Apply Milorganite® four times annually, evenly scheduled throughout the growing season, which could begin as early as March and end as late as October, depending on your location.

Fertilizing Palm Trees
Planting TypeApplication RateSuggested Application
Palms5 to 10 lbs every three monthsBroadcast Milorganite under the entire canopy of the palm.

Transplanting and Planting Container-Grown Palms

Mix into the soil at the bottom of the hole the recommended amount of Milorganite® when planting container-grown palms or transplanting existing palms. Application rates are determined by the height of the palm: 2 lbs. for 4 feet; 5 lbs. for 10 feet; and, 10 lbs. for 20 feet. Water daily for about 45 days.

Planting Palm Trees
Palm Tree SizeAmount
4 feet2 lbs
10 feet5 lbs
20 feet10 lbs


The best time for watering Palms is in the early morning or late afternoon in summer and earlier in the day during winter.

Rich in Iron. Non-Staining.

Iron is essential for the formation of chlorophyll, the pigment that makes palm fronds green. Milorganite contains organically complex iron, and won't stain nearby walks, patios, drives, or fences.

Potassium Deficiencies

Signs of potassium deficiencies—the most common nutritional deficiency seen in palm trees—vary among species, but always first appears on older leaves and may include yellow spotting, yellow tips, and withered or frizzled leaves. Potassium should be applied in addition to Milorganite for a more complete palm tree fertilization program.

Nitrogen Deficiencies

Light-green, older palm tree leaves, and eventually the younger leaves, are a tell-tale sign of nitrogen deficiency. Regular applications of slow-release, nitrogen-rich Milorganite during the growing season can help prevent the problem, or quickly and easily correct this deficiency if you’re already seeing signs.

Iron Deficiencies

If young palm tree leaves show uniform “chlorosis”—an absence of normal green color—it’s showing signs of iron deficiency, and the lack of color will eventually spread to the older leaves. This is a sign of iron deficiency and may also indicate poor soil aeration. Milorganite contains 2.5 percent organically complex, non-staining iron and can help prevent and alleviate iron deficiencies.

Palm Trees are Sensitive and Should Be Treated with Care

Palm trees, in addition to being voracious eaters, are sensitive. If a palm is punctured or damaged using a string weed trimmer, for example, the wounds never heal. Palm trees are also susceptible to chemical burns from quick-release fertilizers. Both make palm trees more susceptible to diseases. Milorganite is non-burning and much safer to use to fertilize palm trees.

Tree and Shrub Articles

planting a sapling

How to Plant Trees and Shrubs

by Joe Lamp'l

Gardening Expert and Host of Growing a Greener World®

pruning a dormant tree

How to Prune Dormant Trees and Shrubs

by Joe Lamp'l

Gardening Expert and Host of Growing a Greener World®

Tree and Shrub Videos

Related Garden Tips

bags of Milorganite

Why Use Milorganite

Learn why Milorganite is the best choice for your lawn.


fruits and vegetables in a basket

Fruit and Vegetable Application Rates

Learn how much Milorganite to apply to your fruits and vegetables.

pink and yellow flowers

Flower Application Rates

Learn how much Milorganite to apply to your flowers.

graphic showing slow release fertilizer provides deeper grass roots than fast release fertilizer

Organic vs. Synthetic Fertilizer 

Learn the differences and benefits of organic and synthetic fertilizers.