tuffifee, you might want to check out these links if you haven't already.

The Miracle Grow with Moisture Control that I tried seemed very soggy compared to other soils that I have used. Some of my plants appeared to rot in this soil.

Which brings me to the links. Soil with lots of moisture holding via peat moss are not recommended for citrus. Makes their roots rot, especially after a year or two once the soil breaks down and collapses into a sort of sludge that air cannot easily penetrate.

I am not an expert with citrus, but looking at your pictures I would think you might benefit from fertilizer formulated especially for citrus.

http://forums2.gardenweb.com/forums/load/contain/msg0514553013662.html

http://forums2.gardenweb.com/forums/load/contain/msg0209173325284.html

http://www.fourwindsgrowers.com/growing/containers.html

Gary

I grow a Meyer Lemon in a whiskey barrel that is about five years old now. I started out with regular potting soil originally. A couple of times a year, I toss some compost on the top. I also fertilize with Miracle Grow for Citrus. Whatever brand you choose, you do need to feed it some fertilizer that is formulated just for Citrus and follow the directions that come with it. Some fruit drop is normal on citrus in my experience.

Thanks for your answers, the links were really helpful.
John - I read in another thread that only 2 - 4 % of all the fruits will really stay on the tree until they are ready to harvest, do you think this is a realistic number?

Tuffifee: Hard to say since I have never counted my fruit as it compares to the initial fruit set. If you consider the amount of blooms {{gwi:30086}} the percentage is probably quite low.

Usually, once the fruit reaches a certain size, the odds of it maturing are really good. You can see in this photo {{gwi:30087}} that the green ones will most likely end up as mature fruit but the small yellow one in the background is done and will eventually drop off.

You should remeove all fruitlets,when they are the size of a
pea for the first two to three years.The roots need to be able
to breathe.Your mix should be free draining,you could add perlite to a standard potting mix.I always use terracotta pots,as they allow air in to the soil and roots.Pot up in steps.You have small trees.Its a false economy to put in huge
pots,thinking you will save time and effort.You should pot up 2-4 inches (next pot size).If you have an 8 inch pot and put it in a 16 inch pot,the outer parts will remain soaked,as the
roots wont use the water up.The soil will go off and the plant will suffer.Let your tree develop its canopy.The tree
has to strain to produce fruit.Once it is well established and has a strong set of branches it will handle it.I have 6
new trees in pots about a metre tall.They are all in 31 cm
terracotta.I wont let any fruit develop for at least two years.Not even one!!! it will stunt their growth.If the mix drains really quickly,you can give fresh oxygen to the roots
without water logging.Feed lightly with high nitrogen,except in winter.Dont feed then.Allow pot to dry out almost completly.I have killed lots of citrus by overwatering.They simply wont grow.Drill plenty of 10 mm holes in your clay
pots with a masonry drill.Go from 3mm 6mm 10mm drill sizes
to avoid cracking pots.THEY MUST DRAIN QUICKLY AND HOLD AIR>
perlite is great for this purpose.Peat moss clogs up the air
spaces.A blend of organics(bark,potting mix etc) and inorganics (pummice,perlite,turface,granite) will ensure all
the above.If you havent time to fuss.Mix potting mix and perlite.That will do the job.Plant at same height in new pot,not deeper.Roots need to be just under surface.Only feed
when you see growth(best about a week after start).Dont think more food is better.Its not.Always water pots first,then water with feed 10 minutes later.Never feed dry roots.When you water ,dont water lightly.flush right through,slowly.then leave until almost dry.roots will search down deep.good luck.

John, thanks a lot, I hope I also can grow lemons as pretty as youurs.
Laidbackdood, thanks for your post- it really helped a lot and I can see clearer now where the problems might be - too much water and lack of oxygen. I will repot and add perlite to my potting mix , that should do the trick. It will break my heart but I will also remove all the fruitletts ( can't I even keep one itsy bitsy tiny one?) , the plant is now in its second year and maybe I can try to leave some next season. As of the repotting, when would be the best time to do so?

"Moisture Control Soil Mix" What that means is that it controls the moisture by not draining. I have yet to find a packaged soil mix that is good for container gardening as it comes from the bag. Here in sunny California where citrus in containers is a big market, beyond the proper soil mix, monthly feeding with a citrus fertilizer containing the micro nutrients is recommended. Citrus is intended to have deep green leaves where the veins do not stand out because they are a darker color. If you over fertilize the new leaves will be oversize. For your container about a tablespoon a month will do it. Your should not need to water throughly more that once a week. Al

SYMPTOMS of clear interveinal chlorosis of younger leaves from Picture 606 and 610. Possible Causes: excess water and iron chlorosis (and copper).

Possible Resolutions (in order of evidence-based reasons):
1) Citrus needs moist but fast drainage growing medium. They are known to be grown on sandy infertile soil. Thus, improve your irrigation practice and drainage in your container growing medium will be help your lemon tree survive and secondarily correct iron chlorosis. You can add pine bark fines ("organic") and LOTS of perlite ("inorganic") to improve drainage. The standard for soiless mix for container culture is 1/3 to 1/2 Perlite.

2) pH is probably not an issue in container culture; however, it should be between 5.5 and 6.5 for growing lemons. Acidifying your potting mix (adding pine bark soil conditioner and agriculture sulfur) will improve iron absorption and chemical exchanges of other minors to correct the intervinal chlorosis. Incoporating small amt.(3) Add iron chelate or iron sulfate to correct iron chlorosis and other nutritional deficiencies. Ironite Plus, for example, include sulfur, manganese, and zinc that will alleviate other deficiencies of minors.

4) If necessary, incorporate some complete fertilizer with minors.

SYMPTOMS of premature fruit drop and interveinal chlorosis. Possible causes: Zinc and Manganese deficiencies, irregular watering, and fungal infection or style-end-rot.

Possible resolutions:
1) Steps 1-4 above may sufficiently correct interveinal chlorosis of young leaves caused by deficiencies in zinc and manganese and possibly the premature fruit drop.

2) Water deeply (avoid infrequent and excessively dry and wet irrigation practices) for healthy root growth and prevent premature blossom drop.

3) Copper fungicide may be needed if there is fungal infection or style-end-rot. Source: http://www.hort.purdue.edu/newcrop/morton/lemon.html

4) Interveinal chlorosis of young leaves can be a symptom of viral diseases as well, however.

Citrus in containers should be in containers of at least 18" in diameter. From the perspective of picture 606, it doesn't look like you need to repot to a large size. You could plant your lemon a little higher up (additional room for root growth), however. If the photo angle is not distorted, I would leave no more than an inch from the rim of the container.

My 3-yr old immature young lemon tree (grown from seed from lemon eaten as an experiment) started weak and died the first year, but it grew back. The second younger lemon "plant" (also grown from a grocery store lemon) about 1-yr old is thriving and out growing the original lemon plant (but not in girth) in the same pot - lots of green healthy leaves.

You may want to research for additional horticultural specs for caring varigated pink-fleshed lemon in addition to the general guidelines for lemons I suggested above to mitigate unresolved nutritional and disease...

It appears that I'm right on the diagnoses: water stress (irrigation practice, potting mix drainage rate, and environmental) and deficiencies in iron, zinc, and especially manganese. Ironite Plus or a low nitrogen complete fertilizer with these micronutrients should mitigate the problems over time. Follow instructions on the product label.

Read this UF article and see the photos here: http://edis.ifas.ufl.edu/HS141

Just prior and during the budding and blooming period (like now for your lemon tree), you could also use a higher potassium fertilizer (the third number - K) than you have been using to alleviate the stem-end rot and premature fruit drop problem.

Less is more when adding fertilizers. Use a low concentration micronutrients (as well as complete) fertilizer more frequently is safer and more effective in finding the right nutritional balance for the plants without causing stress to the plants. Make consistent and small changes over time and in relation to observable results until all problems are managed.

Repotting can be done at any time when a plant is stressed in general; however, using coco coir is not the most important (and economical) change you need to do to correct the moisture and post bloom fruit drop problems if the potting mix is

Tuffifee,Yes remove all fruit until your tree recovers . http://www.hydromall.com/happy_grower19.html
Go to this page.I had a valencia orange that was compacted and
over wet,had lost most of its leaves and showed no growth as
a result. I used hydrogen peroxide(6%) on it and its come to life
and going nuts!!!If your roots are dying,it maybe too late but its worth a try to get some oxygen into those roots.Worked
for me dood.Let your tree recover and dont repot until it looks healthy.Then make the mix of potting mix and perlite like everyone is suggesting,feed little and often.The roots should look whitish,light tan.Not dark brown.Strange as it
may seem,water deeply to flush out and then water with hp.Add hp to you water(al told me that),water 15 mins later
until 15 % of your water runs out the bottom.Leave alone to dry down.Should show new growth pretty soon,once the hp is
broken down in the soil.Dont feed until new growth is going
well.Good luck.

Thanks everyone for all the great information ... I just purchased a Meyer Lemon tree and now I have all the information I need to get it off to the right start (and I also have a better idea of why I've killed 3 others over the past 5 years ... )

I'm not even sure why I bother going to other sources for gardening information anymore -- gardenweb is the handsdown BEST source of information around.