http://edis.ifas.ufl.edu/ch142

have you fertilized at all? if not, try something that has micro nutrients. i use miracle gro all purpose for my potted and in ground plants.

Agreed. Looks like micronutrients are in order, Trojan. This is a pretty common sight here in our neck of the woods (Orange County, San Diego County, Calif.) due to our long, chilly and wet winter and spring. Many of my citrus looked this way. I spoke with Vince Lazaneo, the Home Horticultural Advisor for the San Diego Master Gardeners about a couple of my citrus, and he also suspected micronutrient deficiency.

I use Grow More Citrus Growers Blend, which is an excellent product that provides micronutrients in the correct percentages and concentrations for citrus. I have applied it twice, now to my affected citrus. First time as a foliar spray, and then about 4 weeks later, to the soil, diluted in 2 gallons of water, and then followed up with an additional 2 gallons of acidified water (I use plain old white vinegar, and acidify to 4.5-5.0, use a pH meter, they can be found at any better garden center, and they're cheap insurane). The acidified water will help the tree take up and absorb the micronutrients.

And, for your new trees, you will want to fertilize twice a month during the growing season (for us that's about April through November) with a good citrus fertilizer that has micronutrients. Vigoro Citrus & Avocado fertilizer with micronutrients is decent. You really want to find one with a high sulfur micronutrient content, as this will help to acidify our somewhat alkaline soils. You can also use soil sulfur once or twice a year as a top dressing to help out our pH issue. If we we a lot of cold weather, and a lot of rain, that, along with our somewhat alkaline soils will cause a locking out of micronutrients, and your citrus will look like what you're seeing right now.

And, as far as amending your soil - I don't recommend that. You're going to create this yummy "hole" that your citrus roots are not going to want to leave. You're better off just digging a hole twice as large as your root ball and backfilling with your native soil. Loosen up the soil, and make sure you don't create slick sides in the hole from your shovel. Fill that hole up with water. Wait 24 hours. If the hole has not drained by then, you have a drainage issue, and in that case, you WILL want to amend with some gypsum. Otherwise, you're good to plant. Backfill with native soil, taking care to water in well to remove any air pockets. Keep the rootball at soil level (unless you're in clay, and then elevate the top of the rootball a few inches). Create a nice large well that extends to at least the drip line (tree canopy). You'll want to extend this well as your canopy grows. Set your drips to drip in the drip line of your well. Then, fill with about 1 to 2" of worm castings, another layer of compost, then top with bark mulch. Be sure to keep all clear of the trunk by a few inches all the way around. Water in well. Then, sprinkle your fertilizer around the well ring at the drip line, and water than in. Paint your trunk and exposed branches with indoor water soluble flat latex house paint diluted in half with water to protect the trunk and branches from sunscald. That's how to plant a fruit tree here in S. California :-)

Deep water during the hot summer months 2 times a week, then cut back to once a week in the winter, or no watering at all if we're getting rains. Top dress with soil sulfur once or twice a year. I usually will top dress at the beginning of the growing season in April, when I start fertilizing, and then again, around June or so, when our weather starts to heat up. Remember, NEVER fertilize or apply sulfur to dry trees.

Okay, probably more than you wanted to know, but certainly I hope will help your little kumquat green up :-)

Patty S.

Here is a link that might be useful: UC Davis: The California Backyard Orchard: Citrus

After about 2 to 5 years young trees begin to bear fruit. Commercial citrus trees, for example, bears an average of 45 fruit in the 2nd year, 90 in the 3rd year and 135 fruit during the 4th year under ideal conditions. The quality of fruit produced on young trees is usually poor compared with that produced by the same tree when mature, so don't get discouraged.

The goal of the fertilizer program for young bearing trees is to continue to stimulate vigorous growth of leaves and branches that may compete with early fruit production. After the tree has become established, the goal will be to replace nutrients removed with the fruit and to provide enough nutrients to sustain continued tree growth. Many different fertilizer formulations are available for use on dooryard citrus trees. The most common fertilizer formulations for young in ground trees (less than 5 years of age) are 6-6-6, 8-8-8 or for a 4 year old tree, or older, a 10-10-10 may be used. A one year old tree should be fertilizer 6 times a year. In your area the fertilizer season is early April until Early November. Evenly space the applications throughout this period. A 2 year old citrus tree fertilize 5 times a year, 3rd year 4 times, and 5 years of age and older at 3 times.

For young trees, apply fertilizer uniformly in a 3 ft diameter circle around the tree. As the tree becomes older, the area fertilized should be enlarged as the root system expands. As a rule of thumb, fertilize an area twice the diameter of the tree canopy. Care should be taken to avoid root or trunk damage by uneven placement of mounding the fertilizer against the trunk. For mature bearing trees on well drained soils three applications of fertilizer per year are sufficient, one application in the fall, followed by a second application in the late spring or early summer and a third in late summer.