Why Are My Kumquat Leaves Yellow?

After making some Kumquat marmalade which was absolutely delicious, I decided to grow my own Kumquat tree.

Kumquats are expensive here in Portugal so planting my own tree seemed the logical step says she, who kills most things including fig trees which are meant to be indestructible.

Fingers firmly crossed I planted a healthy tree in April 2016.

Fast forward four months and the kumquat leaves are yellow but apart from that the tree seems healthy with no leaf fall. At first, I thought it was under-watering, no. Then over-watering, negative.

I trawled the internet and the problem appears to be a nutrient deficiency

According to Best Plants

Yellow and dull looking leaves often means the plant is lacking the necessary nutrients magnesium or sulfur. Apply Epsom salt (magnesium sulfate), adding it to fertilizer placed in the soil once per month. For more direct approach, 1 tablespoon can be mixed with a gallon of water and sprayed directly onto the leaves. Be patient as different plants respond faster than others to applications.

This is an excellent website with lots of useful tips.

I then studied various other sites and yellowing of leaves could mean the roots are too wet or too dry, low temperatures, or lack of feeding. I can rule out low temperatures because some days the temperatures have been in the high twenties to mid thirties. Too much water/not enough? It receives no more than my strawberry tubs because it is on the same watering system.

Further investigation reveals it is probably Chlorosis which is used to describe the symptoms of uniform yellowing of leaves.

Green chlorophyll requires iron and manganese. Lack of these nutrients result in the yellowing between the leaf veins

So what’s the cure?

According to the Garden of Eaden blog (I won’t include a link to their website as I was bombarded with annoying popups) chlorosis is treated by

spraying leaves with soluble iron foliar feeds every 2 – 4 weeks or by lowering the soil pH.

Or by applying nutrients to the soil surface. Suggested: soluble, acidic plant fertilizers such as Miracid or Sequestration as a weekly liquid feed. As I have neither of the above in store cupboard I am going to try Epsom salts. It’s got to worth a try, yes?

Dosage: Dissolve 2 teaspoons of Epsom Salts to 1 litre of water and apply every fourteen days.

The experiment started today. I sprayed the leaves and watered the plant with the remainder.

All suggestions,tips and advice welcome!