are you sure this is a kumquat tree? the leafs on my kumquat are smaller and more roundish.
maybe too much water damaged the roots.

I'm no expert, but thanks to this forum I realized my kumquat was being seriously underfed and underwatered. I've rectified that and the tree is much happier.

When you feel the soil, is it dry or moist? Gently penetrate the surface a bit to the just below the surface. If it is dry, your plant is not getting enough water. If moist, your plant has suffered some root damage and just reduce watering. Also, remove the weeds that are growing on the surface as they compete with the plant for food and water. We get to see a lot of Citrus that seem very similar in appearance. Unfortunately, some very common store-bought soil mixes are just awful--basically being peat moss. Outside, in the sun, peat moss, once dried, becomes very difficult to rehydrate. So, peaty mixes either stay wet too long once wet OR, are very resistant to water once sun baked! For all the fretting over Citrus-specific soils (gritty mix devotees, etc.), Citrus are really quite tolerant of a broad range of soils--as long as it drains well. Do you know anything about the soil used?

Thank you all for your responses. @susanne42, someone gave me this tree (in the container) and said it was a kumquat. I had no reason to doubt it :-) No sign of fruit in about 18 months that I've had it, though.

@njoasis, thank you for all your ideas. I pulled the few weeds that were sharing the container. I haven't watered the tree in about a week, since I was afraid the problem was overwatering, so right now the soil is dry right down as far as I can reach. The soil doesn't feel peat-y, it just feels like dirt.

How often in general should a container kumquat (if it is a kumquat!) be watered? As I mentioned, I was watering, and fertilizing with citrus food, it on the same schedule as a dwarf lemon tree I bought earlier this year. The lemon tree's leaves look good, but the kumquat's not so much. On the other hand, many of the lemon's flowers have turned brown and died, so maybe my schedule is not ideal.

Watering depends on your temperatures, humidity, wind, microclimate, your SOIL type, etc.. I have my Citrus pots standing on hot asphalt on the driveway behind the house, full sun all day. It poured yesterday....I watered today (sunny, dry, warm, breezy). In general, I water my containerized ones that are outside in relatively high temperatures/humidity either every day
or every other day. If it's in the mid 90's, maybe twice a day. As long as your soil drains, Citrus will be fine with the water in hot and sunny weather. In the Winter, I keep them cool and on the dry side though.

Well, I was told it was a kumquat when it was given to me. The person who gave it to me was at my house just this week and I referred to it as "the kumquat tree you gave me" and she did not correct me. Perhaps she didn't know what it was herself.

If it's not a kumquat, what might it be?

BTW, it's holding its own. Not better, but not worse. I think I will feed it again with citrus food this week (the first time in a month).

Susan if it were my tree, I would address the issue of SOIL above all else...

Not to be blunt, but truthful, all the fertilizer, sunlight, watering and anything else you do to it is not going to do a thing unless you rid the soil you spoke of and let the roots breath and become healthy with a well aerated mix....

By the way, if the mix is holding too much salt from fertilizing which it probably is, not just water, you will kill the fine roots even further by burning them at this point.

Good luck..

Mike

This post was edited by meyermike_1micha on Thu, Aug 15, 13 at 8:08