Citrus with brown spots

Is this salt burn, sunburn, being root bound, or some combo of the three? Live in rural VA, tree is on a partially shaded patio. Experiences full sun for maybe half the day. It is watered when the soil is dry, is in tropical bonsai soil, and is about 5 years old.

That looks like a spell of not enough water or too much water.

Then the plant got the right amount and put out new leaves.

I am curious what other will suggest.

Hi Gillian, welcome to the forum!
Is your citrus recently having a flush of new growth? If it's lacking certain nutrient the tree will move them from the older leaves to the new ones. Do you observe anything wrong with the new growth? I seem to see crinkled leaves. Top dress with organic fertilizer such as worm casting or compost will help. Or you may remove the root ball from the pot to see if it needs potting up.

May Lotito wrote:Hi Gillian, welcome to the forum!
Is your citrus recently having a flush of new growth? If it's lacking certain nutrient the tree will move them from the older leaves to the new ones. Do you observe anything wrong with the new growth? I seem to see crinkled leaves. Top dress with organic fertilizer such as worm casting or compost will help. Or you may remove the root ball from the pot to see if it needs potting up.

I don’t see much wrong with the new foliage; the crinkling was however initially prevelant in the leaves which are now showing the brown spots. I’ve been told by the folks on a bonsai forum I frequent to wait until spring for repotting but unsure how accurate that is.