Why do you need them to keep growing over the winter? Mine are in a greenhouse all yr. I never heat above 33F. If it gets warmer than that, it is the sun doing the work. Mine only grow in 2 or 3 flushes mostly in spring. All fruit heavily and have great quality.

Now you are in a much cooler area with less sun. But I don't see why you need warmer than 60F at night. Your trees might be too warm for the amount of light they recieve. So you might benefit from more light but don't see why you would want warmer. In CA winters are 30s at night and 50s by day. In Florida its 40s at night at 60s or 70s by day.

Just my take. I'm sure others will have other opinions.

The Fruitnut

Ricitrus,

I am tending to side with Fruitnut...

The only reason why I was growing mine all winter up here in Mass, was to force them to flush and bloom for the enjoyment of growth and fragrance all winter, while everything outside was dead. I enjoy growining things well even in winter..It takes great patients to let them slow down and not see this...Plants just resting for some of us is boring..

Now when I put alot of light with cooler temps, I would lose leaves. When I put the temps warm, very warm with lots of humidity, and lots of lights, they grew, except my lemon meyers, they almost die...
I also had to constanly keep up with pests, because the young flush growth that comes on all winter is a mites and other pest heaven..Let's say feast! It is a constant fight to keep them at bay with actively growing plants.

So I have decided to grow in much cooler temps, lots less artificial light, and still humidity... Going to try and keep the new growth at bay..Maybe grow would be an incorrect word this time around, maybe I should say that I am going to be content if they just rest, stay healthy, and bug free till spring.

Ricitruslover, if you are looking for phenominal GROWTH, then make sure you do the balancing act right with light and warmth...

To much light and to cool of temp = leaf loss.
Too little light and extra warm temps =leaf loss.

You need to find the right balance with practice, and see what you citrus are happy with. This may be a trial an error thing, or someone here will give you just the right advice to make it work..

Welcome and goodluck..:-)

Hi,
Thank you for the great feedback. I have been keeping the collection in a cool greenhouse for the last few years with temps in the 40s to 50s. I found that they suffered at these temps.THe leaves got pale green and some years there was a lot of leaf drop on some varieties. The watering was tricky because the plants dried out so slowly.I keep the humidity level pretty high by hosing down the gravel in the greenhouse and by misting the leaves frequently. This also keeps the spider mites off. I have since repotted most of the plants to a much more freely draining mix. Last year I boosted temps into the 60s and the plants seemed happier. I pruned them back in Jan and they all flushed out in March/April but the growth was not vigorous. I suspect the light level was too low since the plastic was several years old. I am changing it out this fall. The summer flushes were much more vigorous.I also didn't start fertilizing again until after the growth had started up. They all fruited well even the oranges and tangerines. Byron Martin from Logees suggested providing more heat during the winter to keep the root systems healthier and to keep them from rotting. I am happy with the notion of growing them cooler ( it will save me A LOT in heating bills!!)

I love how healthy and lush the summer growth is and I thought if I could get one more flush of growth per year in addition to the summer flush that the plants would really look fantastic. maybe that would be pushing them too much.

I am feeding the fertilizer that is recommended and sold by four winds. Should I also be adding epsom salt to the water every once in a while?

I also don't know if it would be better to prune in the summer vs. early spring? Anyone have any thoughts on that?

So sorry for the long post!!! Thanks you again for all the advice!!

Sean

You know, I am not sure if you could call that pushing them too much. But you know something, I have very healthy trees, but I still feel that they could push more blooms than they have been, I mean tons like when I first bought them.

This will be the first year I am not going to force them to grow with lots of light and very warm temps. They are constantly growing if I do this. I wonder if letting them rest will impact bloom next time around..Maybe more? Hum

The fertilizer recommended from Four Winds, Romeo, will not be enough for your citrus, trust me, been there done that. Eventually you will see deficiencies, especially in the coloring of your leaves. They use more than the fertilizer they recommend. I talk to them all the time and I have been told they use a few in addition to what they are selling you..
Your citrus in containers will need more calcium, and mg than what the ferlizer has to offer, along with iron.

I would recommend you use Foliage Pro which had everything you need...It is by Dyno-gro..If you're using Fp, you won't even have to worry about the epsom salts..;-)

If you don't use it, come back and I will tell you how to use Epsom salts. Used alone with that fertilzer your plants will eventually suffer..

Lots will recommend trimming in spring when new flush happens, but I trim when ever I want. For me it has never caused harm to any of my trees..

Hope this helped you..

Mike....:-)

P.S

This is info about EPSOM SALTS>>> But you need to use a source of Calcium to balance the processs.....This can be found in gypsum...

Citrus need a variety of trace minerals, one of which is magnesium. Magnesium Sulfate is essential for the manufacture of chlorophyll, and using Magnesium sulfate will produce a more robust plant. One study previously posted on the orchid forum in 2002/2003, found adding Epsom salts does not make any difference in the size of flowers produced, but in an experiment the use of Epsom salts brought seedlings to maturity and flowering faster than those which were not provided with magnesium sulfate in the form of Epsom salts.

A variety of frequency and amounts of Epsom salts has been suggested for orchid growers. Mr. Bert Pressman, in an article entitled "Care and Feeding of Orchids" suggests using teaspoon per gallon every time the plant is watered. Other advice offered here for phal growers has been 1 tablespoon per gallon, four times a year, or the same rate in the water during September and October (early fall) to assist in the budding of the plants.

Some orchid fertilizers contain Magnesium, such as PeterÂs Cal-Mag fertilizer (2% Magnesium 5% calcium with a regular 15-5-15 N P K fertilizer, and the Dyna-gro lineÂs Mag-Pro which are available in the U.S. Check the list of minerals to determine if the fertilizer you are using contains Magnesium. Epsom Salts diluted in water offer the same ingredient for much less cost, but some may prefer the other products for ease of use if nothing else.

Epsom salts are inexpensive and can be found at discount stores, drug stores, grocery stores, among other places, in the first aid depts.. YesÂit is the same stuff you use for soaks!

For a real in depth great discussion on all this, look at this....

http://forums.gardenweb.com/forums/load/contain/msg1020215928898.html

or

http://forums.gardenweb.com/forums/load/contain/msg0323131520631.html

Boy you guys are really pushing your citrus if they are growing all the time. It's no wonder you have all these problems with nutrient deficiencies and pests. Most of mine are planted in the ground in my greenhouse. Some are in pots and have been for up to 6 yrs without repotting. I occasionally fert with a complete fertilizer but mostly once a month with 21-0-0. I'm happy if they don't grow at all from Oct to March. They allways have a great color, lots of bloom, and lots of great fruit.

I can tell you that commercial growers don't want their trees growing all the time. They would get way too big and cost too much to prune. Not to mention all the water, fertilizer, and pest control.

Too me if you are pushing your plants like that you are growing an ornamental, not a fruiting tree. I realize that is what a lot want. Nothing wrong with that.

The Fruitnut

Fruitnut...Exactly...
You are right. I think year after year I have been pushing mine to much..

Therefore I want to aim for the results you get by letting mine rest as you do for the first time this winter...I am a little scared they may not do well, or even a couple may croak, but that is the risk I am wlling to take to see if they do alot better with less overhead lighting, meaning, dependant on south facing windows only, and much cooler temps..I have never done this before..Wish me luck will you.

Of course one needs a well draining airating light soil, and, to water alot less at these temps..:-)

Let's see what happens to mine...

I have always had great growth all winter from hot temps and added light, but I am not ready for the pests, and I want to see if letting them rest encourages more blossoms than I would normally get..My lemon meyer never did good though no matter how warm...Maybe they will do better to.

Ricitrus, hopefully you're getting all this..:-)

Fruitnut,

A few MAJOR questions....

At these much cooler temps, are you using supplemental lighting, or you just dependant on the sunlight or daylight for your?

How much sunlight do your trees get?

How much leaf loss if your not using lights?

How green are yours?

Mike: In SW Texas we get about 75-80% sunshine all winter. They are under two layers of poly so that is maybe ~50% of outside light. No supplemental light. And I'm only two months at 33F low and about 55F high. That is the period when I'm getting chilling for the stone fruit. The rest of the yr highs are 80s and low 90s. But they do have 6 months with lows in 30s and 40s, our nights are pretty cold in winter.

There is little winter leaf loss. Just the normal shedding of leaves after they get about two yrs old.

My leaves are light green as the emerge but are dark green as they mature.

You need a period without new growth for flower buds to set and mature. If the trees are constantly vegetative, they will not have many flowers. Plus too much water and fertilizer reduce fruit quality on everything I grow: citrus, grapes, stone fruit, apples, etc.

You have much different conditions than I do. So I can't tell you what is best and sure hope your trees don't die as a result of anything I say.

Good luck!!

The Fruitnut

I should point out that my Washington navels and some others don't grow nearly as much as the Chandler pummelo. The navel once went a whole yr with one small flush. I think this was due to lack of water. It still fruited every yr. The pummelo has twice as many flushes, maybe more. Some of the lemons are the same.

The Fruitnut

Fruitnut,

I just cught something you said that concerns me...I am use to hearing the opposite..

" Your trees might be too warm for the amount of light they recieve"....What do you mean?

I have always been told the warmer the temps are the more a citrus wants light, or sun for that matter, because the roots are kept warm too..
The cooler the roots are which we will be growing at in cool rooms in containers, the less sun or supplemental light they should get..Due to the fact that the roots will be to cool to function properly at that temp with this much light, and cause a host of problems, including rapid leaf loss due to the leaves trying to take up moisture and the roots not working enough to provide so....

Can you please clarify this. Remember, citrus temps may go down quite a bit the your state, but the ground still stays warm enough to keep the roots working efficiently for support of the leafs with that amount of sun and light..

Thanks

Mike

Oops!!! Hitting my desk with my head!!!

Think you meaning that they will be to warm to get (not enough) light in the winter to grow properly...If that is the case, then that explains a little of what I needed to hear..

Ok..........Unbeleivable...lol

Simply put,

THE COOLER THE ROOTS ARE KEPT = less light

THE WARMER THE ROOTS ARE KEPT = more light?

Ricitrus, think I may have somewhere in here found an answer for you and me..If not I am sorry...I should know this stuff...But I will now when ift comes to growing in colder conditions...Sometimes I feel like a dumb blonde. Once I get it, it sticks though, thank God...lol

Somewhere in all of these threads, it tells us at what temperature roots are impaired from functioning properly. If you find it, let me know. If I do, I will tell you..ok

Mike, I've been told citrus roots need to be above 60F to function properly. In the discussion below (see link) their advise is not to give direct sun unless the roots are above 64F. In particular, "The main cause of winter leaf drop is exposure to sun or intense light while the roots are cold." Hope this helps.

fofoca: Do you realize how cold the soil gets in winter in ncal? I can assure you it is well below 64F. Mean winter air temperature in ncal are below 50F and there is citrus all over the place. The soil is going to be near 50F also unless you want to go down 6ft, then it will be somewhat warmer. Those trees are outside exposed to full sun.

During a warm spell in January the air temperature could exceed 70F while the soil is below 50F. Yet the trees don't die in full sun.

The Fruitnut

fruitnut, I didn't suggest trees would die if the roots got cold. I just said the roots wouldn't function properly. If the tree is sun-, heat- or humidity-stressed, this could become a problem. If not, no problem.

From "Growth, Development, and Cultural
Practices for Young Citrus Trees" (Frederick Davies and James Ferguson, University of Florida):

"Media (root) temperatures less than about 15°C inhibit shoot growth in the nursery, particularly for trees on 'Swingle' citrumelo rootstock. Increasing media temperatures from 15° to 25°C significantly increased percentage budbreak (Al-Jaleel and Williamson 1993). Thus, the authors suggested that bottom or container heating may be useful for nurserymen to improve growth of trees on 'Swingle' citrumelo rootstock.

The influence of root temperature on growth was further supported in field studies using budded trees of 'Washington' navel and 'Eureka' lemon. Generally, growth ceased during the season when soil temperatures were below 18°C (Halma and Compton 1936). Air (canopy) temperature was not controlled in either study; obviously it also has an effect on tree growth."

fofoca: Forgive me if I came on a bit strongly there. You did suggest that the tree would, or could, drop it's leaves in the winter if the soil was cold. I've never had that problem in my greenhouse with soil temp in the 40s. And didn't have any problems in CA when I lived in the citrus belt south of Fresno. The soil temp stays below 64F for probably six months in that area. Around the Bay it could be 8, 10, or even 12 months of the year that the soil doesn't warm above 64F. We might disagree about the soil staying that cold, but ave air temperatures do and soil temp closely follows air temp.

My bigger point is I think some people get into trouble trying to force their citrus to grow all yr. Mine does fine resting in this cold west Texas soil. I'm going to record my potted and in ground soil temperatures this winter just to see if I'm full of it as to how cold my soil is over winter.

The Fruitnut

Hi Gang,
Thank you all for the postings. It is very helpful to read what other growers are having success with. What has been very helpful to know is that some of my problems with my trees may not be caused from my winter growing conditions, but rather from the fertilizer I have been using. When do you all stop fertilizing or cut back on fertilizer? I have been using Romeo ( recommended by 4 winds) starting in about March ( once per month) and by June increase to once every 10 days when temps warm up and days are long. I move my plants out of the greenhouse to a full sun location on my patio in mid to late May, and they stay there until sometime in October.
I will say that the summer flushes that I get on the plants seem very good on most varieties. Although some plants don't flush out as well as others some years ( other years they seem fine). The leaves are dark green and the stems seem strong, but I am very interested in switching to this Dyna grow Foliage pro that MIke suggested. I suspect that as I decrease feeding in the fall that perhaps my plants are not getting enough iron or other trace elements and that by the time winter is over the leaves are looking washed out.

Mike what do you think?

By the way, Fruitnut, I don't want it to seem like I want my trees to be in a constant state of growth. I have been keeping the plants fairly cool over the past several winters, but was interested in this idea of warmer temps helping the root systems ( which are in pots) function better during the long New England winters.

Thanks!
Sean

Ri,
God I am sorry for not driectly helping you. Overtired last week and concerned about growing mine in cooler conditions. But I can help you with warmer con.

"My question is If I supply artificial light over the winter and boost temps a bit will they continue to grow during the winter months?" Yes

"How much light should I give them and what type of artificial lights are best"? 12 to 14 hours of light,if,g
(grown in warm coditions".

"I have been reading up on high pressure sodium lamps and mercury halide lamps. does anyone here have any experience with supplemental lighting"?

Yes....First of all I wanted to say it is called a metal halide, not murcury..:-)

"Sodium mimicks the summer, late summer sun and encourages blooms and fruiting, it has an orangey red color to it.
"The metal halide mimicks the early summer sun, and encourages vegatative growth, leaves...There is a bluish tone to the light.....

I have been using one that has 450 watts and another 600. I had them on for about 2-3 hours in the am, and 3 to 4 hours after late afternoon to extend the daylight. I use timers.. This has always worked well for me.

This year because it seems like no one can really give me concrete expereince about growing under "lights" in cooler conditions, I am going to cut back significantly to 11 hours or less and see what results I get.. Since the roots shut down dramaticaly, I am going make them work less. Somewhere last year a member said he stores his in a cold garage with just the winter sun, and they do awsome. He also said he never gets leaf drop. Also the local greenhouse here kept theirs stored to temps as low as the high thirties, dependant just on the winter sun for theirs too, and did they grow beautifully as the sun got stronger, and temps higher. Neither one of these people had to deal with pests, or leaf drop, which is my aim .I'll keep you posted. Good luck

Sean> You live in New England? SWEET!
There is alot involved with container growth. Part of a huge problem with us is that we are not growing in a controlled enviroment such as greenhouses. So as lng as temps in the pot flucuate, so will the plants need for nutriton.
The Romeo is a great product, but it lacks all the micro-nutrients , calcium, and Mg that is needed over time for very healthy plants on a continual basis.Therefore, the reason Four Winds doesn't just use Romeo.
Your soiless media is of utmost #1 importance. It has to be well draining. I suggest you read the container froums. This way, you can feed at (every watering), whether winter or summer, so plants can get at least some nourishment..If the plants has no need for it, it will not be assimulated, and flush out with ever watering...Whe they decide their is need, you want it to ber there.

Fyi...They LOVE foliage pro.. I give 1/4 teaspoon per gallon at "every" watering...

Fruitnut, thanks again for your insight!:-)

One other thing I might mention is that my plants leaves do change color somewhat during the cold weather. I noticed this outdoors in CA also. The leaves "bleach" out somewhat for lack of a better term. Just like my fruit is starting to turn color now as the weather cools, the leaves also become somewhat more yellow. But when it warms back up, they regain their dark green.

If this color change were interpreted as a problem, then we might be tempted to over water or over fertilize.

Not sure I'm 100% right here but that's what I'm seeing.

The Fruitnut

"If this color change were interpreted as a problem, then we might be tempted to over water or over fertilize".

You are 100% right...That is what I use too.. In fact, that is what caused the death of almost everyone of my trees in the past... Bulls eye!

Fruitnut, I totally agree that letting the trees rest in the winter is fine.

In California's Mediterranean climate, it is cold (for citrus), wet, and often overcast in the winter. Thus, the leaves are dormant and humidity is high when the roots are not functioning. There is no heat/humidity stress, and not much photosynthesis going on. In a high-light home, with artificial heating and low humidity, it is a different challenge.

"Soil Temperature and Citrus" - C. P. North and A. Wallace
(http://ucce.ucdavis.edu/files/repositoryfiles/ca911p13-59079.pdf)
"Low soil temperatures-causing low root temperatures-induced foliage wilt in glasshouse experiments with several citrus species on various rootstocks. At soil temperatures ranging from 48F to 62F and with plenty of moisture available, the foliage-especially succulent new growth-wilted, but plants having heat supplied to the roots did not wilt.

"This observation brings citrus more in line with data reported for other plant species. The environmental conditions associated with this wilting included relative humidity of 20% to 55%, light intensity of from 400 to over 1,300 foot-candles-full sunlight approximates 6,000-foot candles-air temperatures of from 59F to 75F, and root media of soil and sand with each containing an optimum moisture level."

The link below is to a discussion by a modern grower of his experiments with soil temperature in the greenhouse. I am not an expert in this area, but what I have read makes sense to me.

I think there is a fine balancing act we have to find for our own growing conditions...

Therefore we know that once the roots temps do rise above 65, during the day, they will drink and eat some, but stop when temps drop at night. Therefore some light and sun is needed....Just not over doing the light and under doing at this critical time of winter, is a challange we all have to meet for our indoors citrus...

It would be easy to store them in a room that never rises above 60, and not provide any artificial light at all..

Good luck everyone..I will sure need it with much cooler temps this year..lol. This will be a new experience for me and my trees...Not for the pests though...

Asta lavesta baby!

fofoca:

If what those posters are saying is true all the citrus in central CA should lose many of their leaves each winter. Ditto for mine in my greenhouse. Mine lose none. My trees in CA lost none. The commercial orchards don't drop their's in winter either. I'll believe what my experience says happens outdoors in winter. I know the soil is colder than they're talking about and some days get pretty warm with full sun during those cold soil periods.

What someone thinks is happening inside their house means nothing to me. I don't know what their conditions are and neither do they very well.

The Fruitnut

Your right, what happens in a greenhouse and outdoors is far different than what happens in a home.. Especially here in New England, dependant of lights and you none..
Therfore how can any of us agree or help each other? How can you benefit the poster or me?

What's the point of thread anyway then if what is happening in someones house means nothing to you?...Didn't you even listen to what we explained was happening? Ricitrus was asking for help about indoor plants and artificial lighting. You have an advantage over us...Show some sympthay will ya..:-)

I am not just a poster by the way, I have a name too, just as I call you by name on each of my posts as well as respect your postings here....:-)

Goodnight...

P.s.... FYI...Artificial lights will never beat all day natural sunlight...Therefore our delema, and your advangtage.....:-)

Hey Mike:

Sorry if my comments sounded uncaring. But I think you took my remarks out of context and they we're directed at you. What I meant was that I don't care about in home happenings as proof of temperature effects on citrus. If the leaves fall off someones citrus in their home it's not cold by itself. Someones home is never colder than my greenhouse (33F ave low to 57F ave high for 2 months) during the chilling cycle. Leaves don't fall off my trees at those temp. So if they fall off in someones house it's not the cold by itself unless they live in an iglo.

That was my point. Good luck with your trees. I've tried to help. Not many others have.

The Fruitnut

Fruitnut,

It's amazing how writen words can be miscustrued for something elset, specially when not speaking face to face, and givin an oppurtunity to express what we really mean ha..Sheesh..

Thanks for explaining and sorry too..

I can tell you this though, not many did come here and help us, but I am sure there is alot of on lookers..lol

As for the leaves dropping at chilly temps, I believe yours don't. Minus the amount of natural light you get to the amount we get, and throw in artificial light, you will though..lol
What we are trying to say, is that forced long hours of artificial light seems to be the culprit...
Man do I wish I culd leave mine outdoors all winter, or in a greenhouse without lights...Who could ask for better than all natural all day sunlight, even it it were for a few hours a day. It is still alot better than artificial all day light..

Funny thing, my navel will drop leaves in my room when cool and lit up by artificial light.
But as soon as I take it to my work, and stick it in the same cool temps, and let the all day sun settle on it, it stops dropping leaves and maintains them all winter, even green..:-)
Maybe there is something to this...