A Gardeners Forum Forums General Discussion The Food Garden Forum Fruit Forum Citrus Fertilizer

I have Dwarf lemon and lime trees. They are both indoors now but go out in the summer. They are both flowering like crazy. I have two questions.

The first is that the lemon tree has fruit on it but it's dropping prematurely. It's not getting over watered. The fruit it's dropping is about 1/4 of an inch long. So what causeing it??

The second question is that none of the stores around here sell citrus fertilizer. I got some 12-5-7 today will that work for now. I know that it's going to promote alot of leaves, but will it hurt it now that theres fruit?

I'm new here so thanks for all your help!!!!

And if anyone wants to know about growing Carnivorous Plants you can count on me.

Fruit and blossom drops are normal for citrus trees. Citrus trees goes through about three stages of fruit drops. The drops begins with flowers following heavy blooms, then week(s) later comes the second drop when fruits are about pea size. The third fruit drop occurs in late May when the fruits are a bit larger.

That said, other contributing factors are water, fertilizer, soil pH and temperature [/weather].

Too much or too little water between cycle of dryness and moist soil can cause fruit and blossom drop.
Water clogged plants can cause petal drop [leaf drop].
Excess water can cause leaves to turn yellow or light green.
Soil pH is either acid [acidic] or alkaline [basic]; ideal pH is 6.0-6.5

Many articles cite different N-P-K formulations, such as ratio of 3-1-1, 8-4-8 or even 13-13-13. The thing to remember is to use a complete fertilizer, meaning all three ingredients of N-P-K are present. Secondary nutrients such as sulfur and magnesium are needed as well, plus micro-nutrients like zinc, iron, manganese, copper and boron. All these nutrients are needed by the plants for healthy growth and development. Your 12-5-7 fertilizer looks okay. At this time, do you still fertilize or apply foliar spray only?

Nitrogen help promotes green leaves and stem growth.
Phosphorous help encourage flowering/blooming and root growth.
Potassium help promotes stem strength and resistance to diseases.

Citrus trees are sub-tropical plants and doesn't really go dormant, however, the roots becomes inactive when the soil temperature falls below 54*F. Try to maintain temperatures of 70*F during the day and 55*F at night.

I'm applying granual fertlizer still. What kind of foliar spray? I have never put foliar on ever.

Some info about Organic Liquid Fertilizer

If your granular fertilizer include the other nutrients/micro-nutrients mentioned in the above post, you may not need to use foliar[organic liquid fertilizer] spray. In case you want to use foliar spray, please do so when the temperature is below 72*F; apply either early in the morning or late evening.

We are not suppose to mention any particular brand of fertilizer, but I do use liquid fertilizer [micro-nutrients] to spray my plants.

Hi, thanks for this helpful info, papito. I am growing a fairly new Valencia orange and a Eureka lemon in my garden beds. They are doing okay at the moment. I gave them a dose of citrus food just before spring arrived (September for us). But citrus trees are a bit of a mystery to me at the moment. Good to know about the required ratios for the nutrients, I will keep an eye on that now. I'd better check when to give them more food.

A ratio of 5-1-3 NPK is the perfect citrus fertilizer. Citrus always take up this ratio, regardless of anything, so having something like 10-12-10, while good for flowering, will leave excess salts in the potting mix. Best to try to stick as close as you can to 5-1-3. They are greedy feeders and love nitrogen!

As previously mentioned, its natural for citrus to drop fruit - when they are mature and bloom profusely, its normal to only expect 1%-5% of formed fruit to reach maturity.

As for foliar sprays, I use them. Once a month I spray my citrus with a weak solution of epsom salts. Research shows that citrus can uptake the magnesium from them very quickly through their leaves, and it makes them glossy and dark :)

I would be interested to hear how people are fertilizing in winter? My fertilizer is meant to be once monthly, but I half the dose and fertilize every two weeks or so. During winter, because my citrus won't go dormant, I will fertilize at a third the full strength every three weeks to keep things ticking over. They don't seem to mind :)

Thanks, aesir. I will try spraying with epsom salts. Previously I gave the lemon tree a dose of the salts because my neighbour said the leaves were looking a little yellow, and it did the trick. Hadn't thought of spraying it on. Probably a good idea for quicker uptake but less chance of overdosing. My lemon tree has been in for about 18-24 months, and this is the first year it has had fruit growing. Is it normal for citrus fruit to take forever to ripen? Our orange tree is slow as well; I planted that in August (our last month of winter). It has one orange just sitting there, and it doesn't seem any riper now than when I put the tree in.

Are you in a warmer climate? Our latitude here is about the same as Washington DC.

Yes, citrus fruit does seem to take forever lol. I have had a calamondin fruit growing for 7 months. It just seemed to grow to the right size but stay green. Then all of a sudden it started to ripen and is due to be picked soon. I have read of some people who waited up to a year for fruit to ripen.

Some fruits need heat or cold to taste right, so it might be worth researching to see what your citrus need.

Spraying the leaves once a month with epsom salts...a very weak solution of it though...helps prevent magnesium deficiency. I also give them a dose of iron once or twice a year. I haven't had to deal with a deficiency yet - prevention is preferable to treatment! Lol.

As for the climate...I live in the far North of England. I think I have forgotten what the sun looks like lol. It quite cold here. We have had an appalling summer - the citrus didn't go out this summer but seem to be alright indoors for the moment.Will have to see what next summer brings!

Hi aesir, I'm sorry about your summer there. We have a friend and also my wife's brother living in London. They said the summer wasn't great there either-maybe next year! We really could do with some of your rain- could you send some over please? We need a summer like you just had! (or didn't have).

How do you dose the iron? Maybe I could just park an old bicycle near the lemon tree and let it rust into the soil?

Lol I would gladly send you some of our weather! My brother and sister live in London - they suffered least this year with weather. It wasn't a good summer for them, but better than everywhere up north :( I may have to move south!

You can buy iron from garden centers and any DIY places that have a gardening section. It normally comes as a tonic or sachets that you put into water. Just add it in with your regular fertilizer once or twice a year. When the days start to get longer and spring approaches is a god time, as the citrus start going into new flushes of growth and the iron helps them along.

Thanks, aesir. I will get some iron onto them very soon then. Yes, you are doing well to grow citrus where you are, but where there's a will there's a way! I'm growing some tropical plants in Melbourne, and they are going reasonably well (admittedly it's a little warmer than where you are).

My father-in-law came from Southampton; moved to Melbourne many years ago- lucky for me, or I would never have met my lovely wife!

Can't blame him for moving lol. I used to live in Canada...wish I still did sometimes! Some of the people here are very rude. The whole country seems to be a bit wild at the moment lol. I would hold off til spring when the days get longer - I'm not sure when your spring is over there lol - until you give them some iron

I see. Maybe the weather is making them grumpy in Northern England. I have heard that Canadians are pretty nice people, so obviously the cold doesn't make them grumpy! The people here are mostly polite, except when they get into cars- we have the world's worst drivers!

Our spring begins in September, but it has been such a warm and dry spring that it's probably more like summer already.

I got home last night and went in my brother room to check on the plants. I was looking them over and notice that there was about 10 flower buds on the ground.

I asked my brother and he said that he bumped it a litlle bit and they all fell off.

Is this normal and what is causing this?

It now close to winter here in Michigan and the plants are all indoors. They get sun from about 10 am until 3 pm; not as much as when they were out side. I also noticed that they got hit by a light frost and it seemed to trigger the flowering.

Lol bumped them a little? Sure he didn't mean a lot :) Don't worry about dropped blooms. Citrus drop up to 99% of flowers depending on their size. If it was really just a little bump, the plant was likely going to drop the flowers anyway.

Citrus, if they have warm roots in winter to grow, need at least SIX hours of really good sunlight and, if this is less than usual, less frequent watering. Don't forget, the light indoors isn't the best quality. Outside, an overcast day provides more usable light to plants than them being indoors on a clear day would.

Aesir,

what is the amounts for the epsom salt and water?

This is great. Thanks!

I've just scanned this thread-- again. Being the proud owner of a new box of epson salts and three citrus trees (see some previous posts, to which the citrus experts replied), I, too, am curious to know what the proportions of salt:water are for watering and foliar feeding are.

I got my trees exactly one month ago. I put them in pots that were too large (thanks for replies to previous posts suggesting how to correct this). Leaf drop has slowed down considerably as they and I have adapted. There is a learning curve associated with adjusting the fans/heaters/humidifiers to accommodate peppers, herbs, and citrus in one room when the sun and outside temp are changing every day! First time in my life I can remember looking forward to a string of 35 degree cloudy days. Presumably then, I'll be able to do tomorrow what I did today!

Now that I have semi-corrected previous problems, I would like to give the little trees a small treat. I got the trees from Four Winds Growers. Their information suggested a fertilizer that was slanted toward acidophilic plants, with heavy nitrogen & "minors" (which are not that minor). (So no names but you know whose azalea formula I'm talking about.) I have watered them about 2-3 times in the last 30 days or so, the 3rd of which was after I sprinkled a 10-8-8 slow release fertilizer. Noted that nutrient needs change with season and development.

Now that they seem to be settling in, should I indulge them in a treat of the epson salt solution?

Marica

All--

I came across this while researching nutrient uptake in citrus. It is a publication from the Univ. of Florida (view online or download the pdf). It is a quite complete discussion of the role of the essential elements in citrus growth, and obviously much of it is applicable to all plants.

Just for fun to share-- "c hopkins cafe, managed by mine cousin mo" was the memory devise I was taught years and years ago to learn the essential elements: C=carbon H=hydrogen, O=oxygen, ... . You have to do some pretty squirelly spelling to make it work. "Cousin" is CuZn, copper and zinc. "Mine" is Mn, molyebdimon (sp?). For plants you leave out the "I" (iodine) in hopkins, but leave it in for animals!

Anyway-- here's the brief Introduction. Following that the article goes on to describe the role of the various elements, deficiencies of them and so on.

(Jiffy-- would there be a place to post this link for future reference to make it more accessible, easier to find?)

link: http://edis.ifas.ufl.edu/SS419

Plant Nutrients for Citrus Trees

Mongi Zekri and Thomas A. Obreza

Introduction

Seventeen elements are considered necessary for the growth of green plants: carbon (C), hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), zinc (Zn), manganese (Mn), boron (B), copper (Cu), molybdenum (Mo), chlorine (Cl), and nickel (Ni). These elements are commonly referred to as essential plant nutrients. An element is considered essential if a plant cannot complete its life cycle without it, and if the problem that develops in its absence is curable only by its addition. Plants obtain C, H, and O from carbon dioxide and water. The remaining elements, called the “mineral nutrients,” are obtained from the soil.Mineral nutrients are classified as macronutrients and micronutrients. The term “macronutrients” refers to those elements that plants require in large amounts (N, P, K, Ca, Mg, S). The term “micronutrients” applies to plant nutrients that are essential to plants but are needed only in small amounts (Fe, Zn, Mn, B, Cu, Mo, Ni, Cl). The use of the terms “minor element” or “trace element" for some of the nutrients can be misleading. For example, the role of Fe in plant metabolism should not be considered less important than the role of K. Iron deficiency can result in total crop loss, so its role is not a “minor” one, and it is not of minor importance. The difference between Fe and K is in the amount required by plants, so the use of the terms "micronutrients" and "macronutrients" is more appropriate.

For epsom salts, I add about a teaspoon to a litre of water and spray. They seem to enjoy it!

Thanks for that link, Marica. Very helpful information .

No prob. Now if I could just get my citrus (specifically lime & lemon, grapefruit has finally settled in) to get on track... . Current strategy, as recommended by someone on this forum: ignore them.

Ignore them- I hadn't thought of that approach, but it might just work! Works with our cats!