Do you automatically think of a leaf spot fungus when you notice brown spots on Ixora leaves, but in reality, it might be a more prevalent condition…?
If you reside in South Florida, you may have observed that Ixoras are planted everywhere, and they have a pale yellow-green sickly tint or rust-colored patches all over their leaves as if they are infected, not to mention that they are falling leaves and some have even died back. Ixora leaves are dark green in hue and contain brilliant flower clusters that bloom all year.
Whether you planted them or inherited them, you’ll quickly discover that Ixoras are not low-maintenance plants; they take a lot of care. From aphid, wax scale, and mealybug infestations to the sooty mold caused by the scale insects’ secreted honeydew, to the extremely prevalent but frequently misunderstood and misdiagnosed illness known as Chlorosis.
Chlorosis is a disease in which a plant is unable to generate Chlorophyll. Most people think of Chlorophyll as the substance that gives it its green color, but it is much more. Photosynthesis is the process of taking the sun’s solar energy and transforming it into chemical energy, which is Sugar or Glucose. It cannot photosynthesis because it lacks or is unable to create Chlorophyll.
This is the most common problem with acid-loving plants in which high ph soils or calcareous soils, because the soils contain a high level of calcium carbonate, which binds the micronutrients to the soil, rendering them inaccessible to the plant, even when you fertilize with traditional granular fertilizers because most of the micronutrients become bound to the soil. It’s possible that this will cause you to tear your hair out. Ixora’s are acid-loving plants that like a pH range of 5 to 6.5 in their soil, which we have at 7.4 to 8.4 in ours.
Here comes the Cavalry
Most of these micronutrients are bound by soil, you’ll need to provide them to the plant in a form that the plant can use.
Open wide here comes the micronutrient plane
Chelated micronutrient foliar spray is the most widely used and least expensive method in agriculture for correcting micronutrient deficiencies because micronutrients are consumed in minute amounts by plants and provide an immediate response. However, as the saying goes, “easy come, easy go,” the response is short-lived and repeat applications are required, and foliar toxicity from the use of salt can occur, so it must be applied in small doses.
How does it get into the plant?
Chelated Micronutrients sprayed directly to the leaves as a foliar spray must pass through three-leaf barriers: the waxy cuticle covering the epidermal cells, the cell wall, and the epidermal cells’ plasma membrane.
Diffusion of nutrients through water-friendly “holes” in the cuticle allows nutrients to penetrate the cuticle. Active transport is used to penetrate the plasma membrane, which is an energy-intensive process.
Problems with absorption
The thickness of the cuticle appears to be affected by the age of the leaf. Young leaves have been demonstrated to absorb more water than older ones. As a result, the repair may not occur in older leaves, and only the younger leaves should develop without the deficiency or spots.
How chelates work?
Chelates is derived from the Greek word chele, which means claw, as in a lobster claw. Chelation happens when a bigger organic molecule (the lobster claw) encircles a metal nutrient ion.
This is known as ligand or chelator. Because the organic molecule (the ligand) may unite and create a ring surrounding the micronutrient, it is protected against oxidation, precipitation, and immobilization in certain circumstances. OK, that’s the best I can offer in terms of a short explanation.
Pruning
Avoid recurrent shearing off tips and branches with mechanical sheers in early spring to preserve Ixora’s blossoming, since this destroys emerging flower buds.
Mulching
It’s ideal to mulch them with a 3″ layer of organic mulch, keeping the mulch from bulging around the trunks.
So what to do?
If you want your Ixoras to look their best, follow my lead and use 12-4-12 palm pro fertilizer as a foliar spray to all of my clients’ Ixoras. I use a 12-4-12 palm pro fertilizer in conjunction with a 22-0-16 root drenches every three months and a 12-4-12 foliar spray every three months.
It’s the ideal fertilizer for Ixoras cultivated in South Florida soils since it contains both macro and micronutrients. The foliar toxicity caused by salts is considerably decreased owing to the 22-0-16’s low salt index, and it has no phosphorus, which is a major contributor to water pollution. The nitrogen is also ecologically benign since it contains an 82 percent slow-release nitrogen.
In conclusion, When Ixora leaves can’t absorb macronutrients like phosphorus and potassium, they become brown. When the plant is affected with fungal leaf spot disease, the leaves of Ixora turn brown as well.