Yes, I use it. It's a wonderful cut flower for huge, impressive bouquets! I don't know its botanical name. (I'm talking of the wild kind----there may be a domesticated version.) It lasts long in the vase. I love it with goldenrod and wild blue aster.

I would guess iron. IÂd give them a very dilute solution (¼ strength) of a fertilizer with iron. See the link below. Here is a link that might be useful: Visual Symptoms of Nutrient Deficiency In Plants

I find that in the late winter my citrus trees usually have lots of yellowing leaves, and ones with darker green veins as well. These are usually the older leaves. As the weather warms they gradually fall off and new, green growth takes their place. I wouldn't worry about applying iron to a ground planted citrus. Just give them lots of nitrogen, starting about now and continuing every few months through the growing season, until about September. I just fertilized my trees yesterday with ammonium sulfate, it's a cheap source of nitrogen that my local OSH carries. Another fertilizer strategy for CA citrus is to look for lawn fertilizer on sale at the big boxes. Don't get any with herbicides, just straight lawn fert which is usually almost all nitrogen. You can frequently find sales on these in the spring. The Meyer lemon is already in full bloom and the Kishu mandarin has small buds. The warm weather has accelerated spring growth.

Thank you Ken & Embothrium! I took a closer look at the root today and here is what I found out. The roots on the south side of the plant were dry. The plant is on the slope facing south. The rain water runs from north (uphill) to south (downhill). Because of this, the mulches on the south side of the gardenia were carried away by water and the mulch layer was very thin. I checked the roots on each side of the plant and the roots on north, east and west side were bright white and full of energy. But the roots on the south side were dry, not dark brown yet, just slightly brown. It rained heavily here yesterday, but the soil on the south side of the plant was already a little bit dry. I touched the ground and the soil temperature was high. So I think found the root cause - root area got exposed to extreme heat. I went ahead and mulched the south side again. And put some stones to hold the mulches in place. I will give some water to it every two days (really don't want to over water it). Will monitor it for 2 weeks to see if things can turn around.