Any ideas?

It is about the temperature of the soil and roots; first the roots must grow and then the leaves/branches will grow.

Actually the branches grow first then the roots catch up.

Silica,

I would like to agree with you; but then we would both be wrong.

Junk,

Forgot to answer your question. Generally roots need to be above 60F for growth; although some varieties will grow at 55.

Johnmerr, The sentences that follows are taken word for word from the book titled "Citrus Production Manual", published by the University of California 2014. == Alternation of shoot and root growth, with shoot growth preceding root growth, was most often reported with seedlings. - Also- Schneider (1952) reported that after the initial spring shoot flush, shoot and root growth were concurrent

I make it a policy never to engage in a battle of wits with an unarmed person.... and that would include Schneider (1952). A quick check to see the error.... many trees planted in the ground will grow bigger and faster in the direction from which it gets more food and/or water. If the shoots grew first, how would they know that more food and water was in that direction? Perhaps with a small seedling the shoot might grow first, getting food from the seed; but beyond that, it is a GIVEN that first the roots grow and THEN the top. If you put a tree in a hole too big or with too much food, the top will not grow at all; because the roots don't have to grow to get enough food for the tree of that size; it is only when roots are encouraged to grow that top growth will follow.

With my trees, only when temps are consistently above 55 degrees at all times I get great growth. If temps dip below that at any given time I get minimal growth!

Mike

In NY, my Meyers our indoors this time of year, but my Meyer flushed in dec and Jan. Last year it flushed in oct and nov outside.

John, I would think that in order for the roots to grow, they must get photosynthate from the shoot leaves, so the shoot should grow first, then the roots. No?

Well John, you are free to believe UCR, and your also free not to believe UCR. Have a great day.

If new roots and shoots grow, will my tree produce flowers?

Vlad,

Wrong again; the existing leaves provide sugars to maintain the existing roots; additional roots grow from those to find additional nutrients and more water. There is an ideal root to shoot ratio of about 1:4; when more roots are established, more leaves can be supported. Photosynthesis is more about fruit and flower production than root development. Every, I mean EVERY intelligent study/publication I have read in my life and more than that every personal observation in 50 years, 5 continents supports what I know for sure about first the roots and THEN the leaves/shoots/stems. Not just trees; but every plant I know is the same. Anyway, as most here know, I have virtually NO confidence in UCR. I learn soooo much more from Florida, Texas, and West Australia... people who actually go out into the field and SEE what works. Most here also know I am a one trick pony; i.e, I know a lot about one thing; and that is Meyer lemons grown in the field; and most of that I learned on my own by trial and error.

Junk,

Flowers and fruits have to do with age, nutrition, climate, and overall health.

John, thank you for your reply. Now I cannot decide whether you or Silica are correct.

Vlad,

I like Silica; he seems to be a knowledgeable fellow; and I would like to keep him as a friend. As to who you think is correct, that is your decision... maybe you have another idea that is even better.

John, I am learning and you and Silica have taught me much.

Here is a research article from University of Florida that found that, for two citrus species, shoots grow first, then roots. http://www.crec.ifas.ufl.edu/academics/classes/HOS6545/pdf/Bevington_and_Castle_1985.pdf. Perhaps it is reversed in other species or under different environmental conditions.

My Meyer always starts its first growth flush of the year in February when temperatures are very similar to yours (daytime 50-60, nighttime 40-45).

-Brett

Well, there actually is no question about the topic. It is a fact that the green part - shoots and flowers or mixed growth are the first active tissue after a "resting" period following overwintering, that can be supported by reliable sources - books, studies, etc. Many are available on the web also. This is when we are talking about citrus plants.

About the original question of junkgson, at mentioned temperatures the activity of growth would be restricted to a practically no growth so the answer is neither of mentioned tissues will develop substantially. It depends also on a type of rootstock your Meyer lemon is grafted on. So if you want growth higher temperatures are needed.

However there is another point in a question you posted but not related to this temperature range. If the tree is mature enough to flower than it will flower and if it is not you can not force it to flower with any temperature, there are other factors that promote flowering. (your question can be interpreted in at least two different ways)

I don’t know what the root stock is, but it is putting out tiny green shoots, so I know it’s alive.

from my limited seat-of-the-pants observations with 60+ citrus in the ground, those on Carrizo rootstock sat still with minimal green/canopy growth for 2 years. After that 2 year point, the canopy took off. those that I chose to transplant, remove, displayed significant root growth and lateral/ depth travel; and with a seemingly disproportionate lack of greenery/canopy growth.

The trees on C35 seemed in balance. The trees on Cuban Shaddock either died (from freezing) or displayed the opposite, that is, more canopy growth than roots.

Perhaps this is all rootstock/scion-type dependent? - And differs for spring flush and follow-on growth?

George,

Best guess is you planted your trees in a hole too large; and maybe you amended it or fertilized before new growth started. At first the roots do not have to grow to find food and water to support the existing canopy; later, when the food supply starts to dwindle, the roots will start to grow looking for more; and then, and only then will the canopy grow. With the limited experience I have with container citrus I have found that if you put the tree in a pot only slightly larger, you get growth in 2-3 weeks (in my climate); but if you put it in a notably larger pot, you might not get growth for 2-4 months (again, in my climate... yours would be slower).

Hi John, in response to your Q's/assumptions: / and additional observations.

Hole too large - negative; my helpers at that time did not wish to dig any extra than they had to - due to the clay and remaining redwood roots in the planting areas. [I removed 30 redwoods in Danville]. If I had to estimate, I'd say the hole was at most 6" diameter larger than the mass extricated from the 5 gal. nursery pots.

Amended: yes/no - just a bit of potting soil added to the Danville clay. Napa soil was not amended.

Fertilized: yes - but also watered inadequately. It was a rough learning curve with all the haunting discussion of root rot on the forum(s). Even though my youngsters were in amended clay, they needed lots of water!

Having said all that, this is what I am seeing with the CCPP budwood that I have been rooting the past couple of years [C54, X639, Carrizo, C35]: The budsticks initially push a few small leaves. Then there is a long period of no foliar growth, but potting up reveals roots growing. Then at some point the stick grows more leaves.

With my two saddle grafted Carrizo/Shiranui experimental rootings: Both were leafless sticks. One of them pushed a small Carrizo leaf immediately. The other did not. The one with the Carrizo leaf pushed Shiranui leaves over Christmas/New years, while the other (with zero leaves) pushed both a Carrizo leaf and many Shiranui leaves early February. The leaves are static on both right now. My expectation is that the roots are growing, and all will accelerate when they are expelled to the outdoors in a few weeks (we are having a cold rainy spell here in NorCal).

I suggest that the scenario is somewhat in between, that the initial growth starts with a small shoots/greenery on most, but it is a very small spurt that awaits significant root development that would push the plant to further its investment in leaves.

The small spurts from the stem come from carbohydrates stored in the stems; and is a response to stress.

According to both UCR and the U. of Florida, beginning 2 weeks after planting a new citrus tree, frequent light applications of fertilizer should be made approximately every 6 weeks to stimulate vigorous growth of leaves and branches that become the framework of the mature tree. Avoid applying high levels of fertilizer all at once,

George,

In my opinion transplanting to a hole "only 6 inches bigger" is too big. The roots tend to be lazy; i.e. they like to stay in the soil they were in; and will not venture out into the new soil as long as there is space not to do so. If you put the tree into a "hole" the same size as it was in, the tree will immediately begin to push roots into the new soil (they have no choice). Planting in the ground in a hole the same size as the pot it was in will result in the quickest growth; and not fertilizing will encourage the roots to grow in search of food. After the roots grow you will start to see leaf and stem growth; and that is when to begin fertilizing.

Silica,

If UCR wrote that, it is because they read it somewhere...likely U Florida; if UF said it, it is because their advice is for Florida growers, who are planting in basically pure sand. A light dose of fertilizer applied at the drip line in that type soil gives the growing roots "something to find/something to reward them"; that advice is not valid for most "ordinary" soils, for which fertilizer should only be started when new leaf growth begins.

Johnmerr wrote = "If UCR wrote that, it is because they read it somewhere"..........Come on John you know better than that. UCR has some of the greatest citrus minds in the world. They are an outstanding resource for the world's citrus industry.

Hey guys..I have a question? Actually my mother did this morning..

When seed is planted, what comes first? The roots or the vegetation? Especially a citrus seed.....Maybe that will tell us what grows first and allows the other to follow? Not sure but I am thinking it would be logical, no?

Thanks

John, the 6" was a max, not a nominal.

Having seen how some universities and research organizations are pressured for output, i always try to interpret carefully. If there is a good, well designed study and data backing the assumptions, that is better, but still keeps me in "prove it" mode until corroborated by other entities.

It makes sense that the foliar spurt of my budsticks is a result of stored up energy. What happens after that is a result of many many factors.

Silica,

Unfortunately I know exactly that, having dealt with the finest citrus research universities in half the world for more than 50 years. UCR sits among some of the finest citrus plantings in the world; but they don't even know what Sunkist is doing. Sometimes UCR is doing research for someone's PhD on something that Sunkist, or people like me have been doing for 10 years! The head of the UCR citrus collection once told a friend of mine (not knowing she was my friend), that, "She really did not have time to talk to "people like me"". On the contrast the Citrus Research Station of Texas A&M was not only willing, but eager to talk to me; because a large part of their performance review and salary is directly tied to their contacts with growers and processors. Same in West Australia; and to a lesser degree Univ. Florida, Gainesville.

Mike, during seed germination the radicle (root) comes first followed by the shoot.

Mike,

All seeds... as in ALL first produce the radicle, which is the predecessor of the roots.

I originally asked this question because my Meyer lemon tree was heavily damaged by frost. I wanted to know when I should expect new growth is it's alive. After reading the comments and advice, I concluded that I should expect growth when the temperatures are around the 60s at most times. If only I could know if my poor tree will produce fruits. But thank you for all your advice!

junk,

I am aware of your original question... the answer to that is when the soil temperature gets to around 60F... not the air temperature. As for flowers and fruit, you did not provide us with enough information to make a guess; i.e, the age of the tree, the rootstock, photos, etc.

My tree is of fruiting age, most likely around 2-3 years. It produced 10 lemons last year. I bought the tree from Home Depot last year, so the rootstock is unknown. I do know it's a standard rootstock because the tree is not dwarf size. The actual rootstock is not listed on the tree's identification tag though. I am seeing small spouts coming from the main trunk above the graft line, but none on the main branches. Even after pruning, the branches are still turning brown. Could they be dead? I attached photos this time. Thank you for all the advice everyone has given!

Prune the frozen (brown) branches back to the first green bud; keep it warm and don't over water it. It should begin to grow again in March; and if it has had fruit before, there is a good chance it will make fruit this year.

Thank you so much for helping me. This thread has been much more helpful and reassuring than all my other research. Thank you for everyone who spent their time to help me and my Meyer lemon tree!

When the weather got warm, my lemon tree exploded with new growth. I guess everyone was right, it just needed to get warm.