I planted some small cicas in the home garden. Some leaves have yellow spots as I can solve the problem. Furthermore I have been advised to also give iron to them is advisable. Thank you
cycas are very slow-growing plants, whose exotic appearance leads us to think that they are delicate, difficult to care for, or easy prey to insects and fungal diseases; in reality they are resistant plants, which if placed in the correct climate do not require great care and survive without problems even in critical conditions; the only "flaw" they have is a very slow development.
Having said that, it often happens that the cycas plants fill up with small spots on the foliage, usually yellowish; the main reason is usually due to a lack of nutrients in the soil. The fertilization of cycas is generally practiced by spreading at the foot of the stem a small handful of slow release granular fertilizer for green plants, which will be gradually dissolved by the water of bad weather and watering; by supplying this fertilizer in early spring, the plant will have it for about four months, and therefore in practice for the whole growing season. If you don't like granular fertilizer, dissolve some fertilizer for green plants in the water of your cycas' watering, every 15-17 days, from April to September.
It happens that in particular conditions the cycas suffer from ferric chlorosis; in this case, however, they hardly have yellow spots, rather the color of the foliage, usually a beautiful dark green, becomes progressively lighter and lighter, until it becomes almost yellow: all the foliage, starting from the thick and fleshy petiole, up to the apex of the frond.
In the event that one day your plant turns completely yellow, you may have to practice a greening treatment, using a fertilizer appitito; but in this case I think it is not this problem.
It also happens that some spots are due to the presence of parasites on the plant, generally they are mealybugs; in this case, however, you should see the insects well attached to the leaves with the naked eye, on the lower page. If you notice small white, swollen dots that burst at the simple pressure with a finger, then spray the plant with white oil, activated with an insecticide product based on pyrethrum. Or, if the spots are few, and the insects in small numbers, remove them with a cotton swab dipped in alcohol. The mealybug grows on plants grown in very dry conditions of air and soil, and lack of ventilation.
The umpteenth motio for which some cycas have spots is often due to excess watering, or excess water due to bad weather; in this case, in addition to the spots, the fronds are soft and a little limp; if the plants are in the garden, and therefore it is not possible to dose the quantity of water they receive, it is only to be hoped that the soil will dry with the sun in the coming months.