By Tim Clancy.
Queen palms (Syagrus romanzoffianum) are popular ornamental “trees.” They are planted so frequently that some in the nursery trade lump them in the “bread and butter” category of plants along with Agapanthus, daylilies, azaleas, and impatiens, among others. It would seem that with so many specimens installed in the landscape, we would know a considerable amount about how to take care of them. Unfortunately, that is not the case in many locations. The queen palm is native to South America. Its growth habit is described as solitary (single trunk) with a canopy of about fifteen leaves. Those are fully developed mature leaves about fifteen feet in total length. The palm likes a slightly acid soil and has high nutritional requirements. Under ideal cultural conditions and care, the palm has dark green leaves. Most of the soil tests I have reviewed in San Diego over the years tend to be on the alkaline side of the equation. This makes the nutritional component all the more critical as alkaline soil can cause an alkaline induced chlorosis. In many cases, this can be counteracted by the timely and regular addition of a fertilizer specifically formulated for palms. Water is, of course, another necessary component, and the more the better for these monocots.
Once the fronds are yellow, you can’t turn them back to green like you can with other plants. The fertilization in this case is a preventive strategy. What happens when the nutrients are not available to the palms? The leaves turn yellow because in the creation of new fronds, nutrients are dispatched from the oldest existing leaves to the newest emerging leaves. As the nutrients from a leaf are exhausted, the next youngest leaf is sacrificed and so on and so on. This is why you will often see queen palms with three or four green leaves and then several leaves of varying shades of yellow. This problem is often compounded by pruning. As the yellow fronds are considered by many to be unsightly, they are often removed and the palms resemble shaving brushes. This then starts the nutrient extraction from the remaining fronds. As you look around, you can easily identify queen palms that have been under-fertilized as they often have far less than a full complement of leaves. The well cared for queen palm can be a beautiful compliment to any garden. Some key points to remember are that the palms are capable of producing and maintaining fifteen fully mature leaves. Under good growing conditions, they will produce about six new fronds each year. If a certain look is desired, it is recommended to remove no more than six fronds per year. It is also acceptable and desirable to remove the edible fruit. This fruit is a nuisance and attracts undesirable wildlife. The number one requirement is to fertilize the palms regularly. I currently recommend a regimen of four times per year with a palm fertilizer. The amount will vary by palm size and manufacturer, so always refer to the instructions on the bag.