What Is Date Palm Leaf Spot: Learn About Date Palm Leaf Spot Treatment

Large Date Palm Tree
(Image credit: cnair60)

Date palms can add an exotic flare to the landscape or be used to transform a humdrum backyard into a tropical paradise in areas warm enough for them to be planted outdoors year-round. To keep those date palms looking their best though, it’s important to brush up on common problems of date palms. The most common problem these plants have, by and large, are leaf spot diseases. There are several different pathogens involved, but they’re difficult to distinguish outside a lab, so we’ll discuss them as a group. Read on to learn about leaf spot symptoms and date palm leaf spot treatment in this informative article.

What is Date Palm Leaf Spot?

Any time your date palm develops circular or elongated, brown to black, potentially oily or water-soaked appearing spots, it’s a clear sign to pay attention. These spots are a clear indication that a fungal pathogen is feeding on the dermal tissues of your date palm. Although leaf spot symptoms can look really scary and explode out of nowhere, these diseases tend to be of very little consequence in the long term. They’re primarily cosmetic, so you don’t need to panic right away. However, if leaf spot is developing, it says a thing or two about the conditions where your date palm is growing. Mainly, that it’s humid and warm. These are the keys to success if you’re a leaf spot fungal pathogen in date palms. So, it’s really important to consider the air circulation around your plant and how you water it before you begin any sort of fungal eradication program. For example, if your palm is still fairly young and small, resist the urge to water it on the leaves. This is just asking for a fungal disease. Instead, water the palm at the base, either manually or using an irrigation system, and at a time of day that will allow the palm to dry completely and as quickly as possible. Also, if it’s planted in tight proximity to other plants, you may want to consider digging either the palm or the other plants to increase the air circulation. That way, natural breezes can help reduce the humidity that fungal leaf spots need to thrive.

How to Cure Leaf Spot on a Date Palm

Date palms with leaf spot disease are often suffering from nutritional deficiencies at the same time that their fungal pathogens take hold. This is important to note, because generally advice on curing leaf spot includes removing infected leaves, but if you do this with a date palm suffering from a nutritional deficiency, you risk killing it entirely. Instead, feed your plant well and improve its nutritional state once you’ve corrected the cultural conditions mentioned in the section above. While you’re waiting for your plant to recover from its nutritional deficiency, apply a copper-based fungicide to the entire canopy to kill any spores that may be lingering. You can use copper fungicides even if you intend to eat your own dates, just be sure to observe any pre-harvest interval times specified on the label for safety. Only remove palm fronds if they’re badly damaged; otherwise, leave them intact at least until your plant has had time to fully recover from any nutritional problems and you see new growth emerging.

Kristi Waterworth

Kristi Waterworth was a regular contributor to Gardening Know How for many years, answering countless queries on plant pests and diseases.