Wherever you heard..."(I heard you usually do not do so (fertilize) in the first season anyways)" is COMPLETELY WRONG. During the first few years, it is VERY IMPORTANT to apply fertilizer to young trees in order to stimulate the vigorous gowth of leaves and branches that will become the framework of the mature tree. Begining about 2 weeks after planting, frequent, light appplications of fertilizer should be made approximately every 6 weeks. You do not say whether the tree is growing in a container or in the ground. As you are in California zone 10 I am assuming that the tree is in the ground. As you did not fertilize the tree up to this time of the year you now have even another problem, other than the nutrient deficiency which is causing the yellow leaves, and leaf drop. For outdoor trees planted in the ground, fertilizer should not be applied between October 1 and February 1 for the first year or two, especially in regions where unseasonable cold damage can occur. When unseasonably warm temperatures occur, during the winter months, young trees may flush more easily than larger, mature trees, especially trees planted the previous fall or spring. Trees fertilized after October 1 can easily flush ADDITIONAL, tender growth, making trees even more susceptible to being killed by the cold weather. Any cold hardiness that is built up in a citrus tree is lost when the tree flushes new growth. You can do what you deem best at this point. If it was my tree I would take the chance and fertilize as the tree is in a dire deficiency. Because the tree is still small, you can protect the tree if a cold snap should indanger the tree's life. - Millet

Thanks Millet! The tree is currently in a pot. I reappy do appreciate the information, thanks again.

-Jeff

The other thing I can think of (and what happened to me) was over watering. I tried to buck the common wisdom and used a self watering pot. Big mistake, plant grew slowly and lost many a leaf. Within 1 week of putting it in the right pot tons of new leaves started popping out all over.

Scot

In a pot you can bring it inside and put it in front of the sunniest window. My baby calamondin started yellowing 3 weeks ago because it was in too-draining a medium (orchid mix), and wasnt getting fertilized enough. Shes looking a few shades better already. I have gone to half-strength ferts for winter, because I dont have the best sun exposure. I started light ferts on 2-week stabilized transplants.

Millet and others here DO encourage gently soaking the prevoius media off roots so there isnt a significant drainage gradient, and soaking seems to be gentler than picking roots out.

good luck!

Thanks everyone for your concern. I've lightly fertilized the plant and hopefully it will show more color and life. I'm considering using Iron foliage spray - yes, no, or maybe?

Thanks again!

Jeff, you can use iron (either Iron sulfate, or iron chelate) as a soil fertilizer. However, you are correct, do not use an iron supplement as a foliar spray on citrus. Lastly, be sure that the fertilizer you are using, contains trace minerals. Good Luck. Take care. - Millet

Jeff, it's a good idea to use iron as a preventative 2-3 times a year..
Though I prefer using iron mixed w/water, there are some types that can be used as a foliar spray..Depending on the brand you purchase..It will state on the package which method to use..Toni

Jeff- Sorry to complicate matters, but a high soil pH can inhibit iron uptake/absorbtion. In my case, I have to use Sprint 138, opposed to the standard Green Light brand. (Yes. Even Becker Underwood understands that not ALL pH is easily adjusted.) Check the pH, just to make sure you aren't throwing money away on an insufficient iron supplement. Good luck.

Here is a link that might be useful: Sprint 138

AnotherAlterEgo: Do you recommend anything specific to check the pH level of our water? Are litmus paper good enough? What is a safe pH level? If its high/low how do I correct the water pH? (Sorry for the million questions - thanks for your help and time)

Is there a specific citrus fertilizer that works well for you?

Again, thanks everyone!

Jeff - I use a Hanna meter, but it was several hundred dollars, and not necessary for a hobbyist. The strips, or any cheap kit, should give you enough information. Ideal pH for citrus is 5.5-7.5. But my soil/water pH is around 8, so it's possible to grow them out of the 'ideal' range. This is why I have to use special iron, by the way. Assuming your pH is out of wack, you may be able to correct the problem fairly easily. My pH problems involve soil and water and can only be corrected with an acid-injection system (such as you would see in a hospital boiler room). I don't particularly want 55-gal. drums of acid delivered to my home, so I just take 'baby steps' with regard to my pH. Chances are, you don't have the same environmental issues as I do. So, don't fret over it. I use a variety of fertilizers. The easiest and safest is Lutz Citrus Tablets. They were designed specifically for citrus (with all the minors and then some) and you only have to use them once per year. As well, I occasionally use Scotts Acid Special (21-7-7), with an addition of magnesium sulfate (for fruit quality) and Sprint 138 (iron). I also use Scotts Sierra Blend (18-7-11) -- the 3-month feeding -- once in a while. I went through an 'organic' phase, during which I used a lot of compost tea, kelp and fish emulsion. But I wasn't overly happy with the results.

AAE, I've a question about fertilizing.
You say you use Scotts Sierra Blend, a 3 month feeding...Ok, do you also add other fertilizers during this period? If so, wouldn't that be too much food?
Feeding this way scares me.
So, what I'm asking is, I use a Citrus fertilizer that's supposed to last 3 months..Can I also use other fertilizers in that 3 month period, or would I be overfertilizing? Thanks, Toni

I got a small round cartrige with 100 pieces of pH paper and the color guide printed on the outside, was like $3 at a Teacher Supply store.

I also save rainwater in buckets or milk jugs (it hasnt rained sufficiently in weeks here, Im hpoing today!) The rainwater used regularly, from what I understand, will delay or avoid the need to flush salts out of your soil, and its a slightly acid pH.

pH test strips are not very accurate but will get you in the ball park. pH meters will range in cost from about $50 to well over $1000. Meters cheaper than $100 rarely have suffcient accuracy and precision and growers often toss them after one to two years of frustration. If you do wish to purchase a pH meter listed below are things to consider when buying a meter to be used in a greenhouse or nursery. Accuracy & Resolution, Auto shut-off, Built-in vs. separate electrode,calibration, electrode storage, replaceable electrode, range, readout(digital or analog), temperature compensation, waterproof vs. water-resistant. All above are important, so you can see why a pH meter under $100 are often unreliable. - Millet

Toni - Sorry. I should have been more clear. I use everything that I mentioned, but not at the same time on the same plant. With all methods, I find myself regularly adding iron or epsom salt. There have also been times when I've had to topdress with gypsom, because of low calcium levels in the water. And, once in a blue moon --when I see grossly oversized leaves *and* fungus-- I'll use a copper spray (kill two birds with one stone).

AAE, oh you were clear, but my question was, do you use Lutz Tabs and Scotts Sierra Blend in the same yr..So, in other words, since Lutz are a once a yr food, do you add additional food throuhout the yr? Toni

Toni - I don't necessarily mix fertilizers. But, whether I'm using Lutz or Sierra Blend (or whatever), it's not uncommon for me to add some iron or epsom salt to my irrigation water.

Mine Dwarf tree is turning yellow all of the sudden as well. Mine have always done great it is about 2 years on the same pot. I moved it about 4 months ago to full sun. While it fruited this year they never fully ripened.

It has started to cool off for the winter in San Francisco so I cut back on the water. I was giving the pot one good water per week and over the last 2 weeks I cut back a bit. Could that be the trouble? The leaves went from waxy green to dry yellow and are starting to curl.

Please Help

first, you should probably start a new thread if you have a different problem.

really fast change might be bugs, get a hand lens and look closely, some insects are really tiny.

When mine need watered, the leaves get a touch limp, then might change color. If its fert they need, they seem to gradually lighten.

You say fruit never ripened- Did it fall off? winter is the prime ripenening season, are you sure you didnt take the fruits off too early?

Actually, green leaves that quickly turn yellow, are often an indication of overwatering or, possibly in your case, inadequate drainage. This problem tends to rear its ugly head this time of year because there isn't as much evaporation or transpiration. Make certain your container is not sitting directly in a drainage tray. When you water, soak the rootball completely. If your container is still 'heavy' several days later, chances are your soil tilth is unsuitable.

Thanks, I will check for bug. I see a few ants but that is it. The comment about the fruit is I have had the friut on the tree for 6 months and it seemed to just stop. I figured that since this was the plants first fruit it needed a second season to develop well, my Mexican lime tree did the same thing.

As for drainage, it is draining well, I have th pot above the ground on bricks so I can see the drainage is good.

If the leafs are yellowish and curling does that still sounds like overwater to you two?

Is it ok to ferilize this time of year?

Moayediberg, Just because water comes out the bottom doesnt mean the potting medium is drying out far enough down.

My well meaning but garden inept fiance planted some mulberries in yard topsoil and clay, and once the soil had dried/shrunk, when watering, the water came right through- The water was draining, but not because it was a good soil environment.

Stick your finger into the soil, is it still moist underneath? Can you gently slide the tree out of the pot? if the roots are stinky and/or mostly brown, theyre probably kept too moist. Healthy citrus roots should be mostly white, especially at the tips. Good luck

Again I have to say the more I learn - the more confused I get. If the PH is high (6 & above) that is alkaline...RIGHT? Lower PH is going to acid soil..RIGHT?
I keep hearing that citrus need lots of nitrogen ..which makes acid soil. Yet, citrus fertilizers are not higher in nitrogen than P & K.
I'm not a pro at this & wish someone would explain this in simple terms. I have a couple that are in bloom right now & I remember that I should change ferts. to either higher nit. or higher P but don't recall wich one ( while they"er in bloom). I've been lucky in the past w/my guessing. The 2 that have blooms need watering so what should I give them for fert? What should I give the others which may blossom soon? Thanks much... I WANT FRUITS.
Patty

Patty,
Neutral pH is 7; anything lower is acidic, anything higher is alkaline.

Others more knowledgable will chime in here, but I think that for container citrus a ratio of 5-1-3 or so is recommended. I think most citrus fertilizers are at least as high in N as they are in P or K.

I got confused when I first researched this and found recommendations for 6-6-6, 8-8-8, and so forth...these recommendations were for Florida citrus in the ground. Container citrus are handled different.

I've never heard that you should change ferts when plants are in bloom. Anyone? I do recall seeing reports of nutrient uptake by heavily fruiting trees where the K uptake exceeded the nitrogen and phosphorus uptake. Presumably this is because of the K in the citrus fruit, though I don't know whether this is stored K or whether this extra K needs to be made available in the fertilizer.

I will use a 10-50-10, or somewhere in that neighborhood, during late winter/early spring. Although this formulation is generally sold promote blooms, I use it mainly for upward growth of rootstock (which I plan to graft in coming months). Unlike nitrogen, plants don't necessarily use all the phosphorous quickly. In my case, the alkaline soil inhibits uptake even further. It's always a tricky situation and I usually end up sending out soil samples to find out how much supplemental phosphorous is required.

Patty, the nitrogen in fertilizers can make the growing medium become either more acidic (lower the pH) or less acidic/more basic (raise the pH). There are three types of nitrogen used in fertilizers: ammoniacal nitrogen (NH4+), nitrate nitrogen (NO3-) and urea. Fertilizing with ammoniacal nitrogen causes the medium-pH to DECREASE (become MORE acid) because H+ (acidic protons) are secreted from the tree's roots. Urea is converted into ammoniacal nitrogen in the growing medium, and therefore can be thought of as another source of ammoniacal nitrogen. In contrast, fertilizing with a nitrate nitrogen fertilizer INCREASES medium-pH (becomes LESS acid/more caustic) because the tree's roots secrete bases (OH-). Stressbaby is correct in stating that 7 is a neutral pH. Numbers lower than 7 denotes an acid solution, and numbers grater than 7 denotes a basic solution. The pH scale is also logrithmic. So a potting soil with a pH of 6 is ten times more acidic than a potting soil of pH 7. A potting soil with a pH of 5 is ten times more acid than a potting soil of pH 6, and 100 times more acidic than a potting soil of pH 7. A potting soil with a pH of 4 is ten times more acid than a potting soil with a pH of 5, and a 100 times more acid than a pH of 6 and 1000 times more acidic than a potting soil with a PH of 7. An so no and so on. Citrus will ALWAYS take up nutrients in a 5-1-3 ratio no matter what formulation you give them. Much more important than what type of fertilze to use for flower fruit set is an ample supply of water. Water is the prerequisite for ALL STAGES of fruit development. Water stress is particularly dangerous during fruit set, leading to a massive drop of fruitlets. Increase in size and juice content are also largely dependent upon the availability of water. So at bloom and fruit set, keep the moisture level of the growing medium up. This is where a well draining, lite aerable "soil" that at the same time retains a higher amount of water, such as CHC's, becomes important. Nutrition from fertilizing is important as well. Potassium plays a special role in fruit development. I would recomend a fertilization with a fertilizer formula higher in nitrogen and potassium, such as a fertilizer with a 5-1-3 ratio, or something more or less close. I also give my trees a nitrogen/potassium foliar spray, using Potassium Nitrate, a month before bloom and again a month after fruit set. Take care. - Millet

Patty, what type of citrus fertilizer are you using? One brand I have is Hoffman, 12-6-8 ..which means nit is higher than P and K.

Moa, you mention seeing ants..It could be a family of ants just found a plant to move to, but in some cases, if there's ants, there's also Scale. Check stems, under and upper sides of leaves. Do you know how to detect scale?
When mature, they are easy to spot..the look like bumpy armor. I'd check my citrus for these pests..Toni

Thanks Stressbaby, AAE & Millet. The only fert I have now that is lower in P (phosphate) is pond plant fert...15-7-12 (not good for food plants) , & tomato food...18-18-21. I have blossom booster 10-30-20 but maybe I'll use that on trees that have no blossoms.(?) I also have a box of blood meal...12-0-0. Says it's INsoluble. I think I bought it just to confuse myself more LOL. I never hear anyone talk of bloodmeal here. Doesn't say what kind of nitrogen, just that it's derived from blood meal. I think I'll scratch some bloodmeal in soil & fert. when I water tomorrow. To be safe I might use acid plus or Peter's 20-20-20 or the tomato food with bloodmeal. I can't find ANY citrus fert. around here & last I looked on net, it was expensive. Thanks again all, I took notes. Anyone else use bloodmeal?
Toni, I know what NPK means LOL. Last couple times I fertilized I used 33-11-11 (acid plus).
thanks again
Patty

Patty, of the formulas you list above, 15-7-12 would be the closest fertilizer for containerized citrus. 10-30-20 would be the least acceptable for citrus, in fact 10-30-20 is almost exactly opposite of a good citrus fertilizer for containerized trees. - Millet

I used 3 parts 18-18-21 & 1 part 33-11-11 today. I heard (from a not-so-reliable source) not to mix, but I see nothing wrong w/ it. I will have to shop around for the right fert you mentioned Millet.
So, should I scratch some bloodmeal in the soil? Pure nitrogen. thanks,
Patty

Patty - There's no need to use a high-phosphorous fertilizer to promote citrus blooms. In my experience, using it for that purpose, it really didn't yield good results. Specifically, I tested it on Calamondins. The plants which received the "blossom booster" mix consistently had fewer blossoms and were ganglier in appearance, than the Calamondins which received the high nitrogen formula (Scotts Acid Special). If you are in search of a decent ready-made fertilizer for Citrus, try Osmocote for Roses. It's almost identical to Scotts Sierra Blend. I've used it myself many times, with good success. (I've also used Citrus blend on my roses, with the same good success.) Osmocote is not the cheapest fertilizer out there, but it's available just about everywhere.

I agree with AAE, it is not a response from phosphorus based fertilizers that causes citrus to bloom. Giving a citrus tree high phosphorus will have nothing to do with the tree obtaining a higher degree of bloom, in fact it would not be benifical to the tree. What casus citrus trees to bloom is various hormonal and stress factors and for containerized citrus this means giving the proper growing methods. - Millet