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oberci

Caring for IN GROUND Citrus

oberci
11 years ago

There seems to be a wealth of information regarding container-grown citrus, but I'm having a hard time educating myself about the proper care for In-Ground trees. If those of you with more experience can share your thoughts on this thread, please do so!

Here are some of my personal questions, but feel free to elaborate on anything else you think is crucial to successfully growing in-ground citrus.

1. How often do you water and how much water do you give it? Is there some kind of ratio for watering in relation to tree size?

2. How often do you fertilize? How do you apply fertilizer? If I use Foliage Pro on my container trees can I also use it on the in-ground citrus?

3. How do I prune to to encourage fruit or is this necessary at all?

4. Is it a good idea to put some kind of ground cover or mulch on the areas around the trees? Is a layer of peat moss a good idea or are pine needles or wood chips better? How close to the trunk do you put mulch?

Here are some pictures of the trees we planted a couple of months ago. Happy to hear any insight on their condition. Ignore that unfinished wood chip path it is a work in progress :)

Left to Right: Red Grapefruit--Cumquat(in back)--Meyer Lemon

{{gwi:595947}}

M.Lemon put out a good amount of growth and has little fruit on it (yay!)

{{gwi:595949}}

{{gwi:595952}}

The Red Grapfruit hasnt made any flowers since we planted it and is doing this leaf curling thing. What should we do?

{{gwi:596116}}

Looking forward to hearing from everyone!

Comments (22)

  • johnmerr
    11 years ago
    last modified: 9 years ago

    Well, what I know most about is the Meyer; I have 8,000 trees now and will have 15,000 by end of July, but that is in Guatemala.

    I also have experience with Meyers in California and on a cupla other continents; so here goes.

    First, it would be helpful to know where you live and what is the pH of the soil; and on what rootstock the trees are grafted.

    To answer your questions.

    1.Water once per week... a little more often in very hot weather; give them a slow soaking to wet the soil at least to 18 inches.

    2. I fertilize my trees 3 times per year (January, May, and October); apply the fertilizer at the drip line and water in well. Any good balanced citrus fertilizer will do; if you have had good luck with FP, you can stay with that.

    3. If you want fruit, spare the clipper; only prune for the shape you want. Citrus make fruit on new growth; and they need all the leaf surface they can get to make good fruit.

    4. I am not a big fan of mulch; but many here are, especially garden growers. Fir bark or pine bark make good mulch; keep it at least 6 inches back from the trunk.

    5. I would paint the trunks with white paint to prevent sunburn of the trunk, which can kill the tree. Buy the cheapest white latex paint and thin it 1 to 1 with water.

    6. The kumquat is pretty easy to care for, unlike the Meyer which is a bit touchy...less so inground than in pots.

    7. The grapefruit is the easiest to care for, unless you soil pH is over 7.5, in which case you will need to use chelated minerals, or the tree will not absorb them. Your foto looks like your tree isn't getting enough water; and I would prune off the downward hanging branch.

    Your trees look healthy, perhaps a bit underfed; but keep doing what you are doing, just check the label recommendations for amounts of fertilizer.

    For my garden trees I still put a good foliar fertilizer on them every 2 weeks; but my garden trees have to compete with other plants, and yours are cleared underneath as they should be... maybe once per month is enough for you, if you are applying the right amount of fertilizer, and 3-4 times per year.

    I see you are using drip irrigation; if you have a fertigation system, you might prefer to apply a more dilute fertilizer every time you water... sometimes called weakly weekly.

  • timsf
    11 years ago
    last modified: 9 years ago

    Hi Dandy,

    You may want to add your Sunset Western Garden book zone to your member page descriptor, as this gives us a better idea what region in CA you're located and what your corresponding min and max temps are so that we can better advise. BTW, if you don't already have this book, it is an invaluable 'gardener's bible' and is highly recommended! Since you say in another post that you're in Sacramento, you would be in Sunset Z14 (though you very well could be in SZ9 if you're even 15 miles away as in Orangevale!). As for me, I'm in SF in Zone 8b-10 (depending on where you're looking), but more importantly I'm in SZ17, so put my answers in the proper (temperature) perspective given our vastly different climates! :-)

    In addition to 1 potted Meyer in 5-1-1 mix (really an on-going experiment to serve as a comparator), on my postage-stamp sized SF lot, I've been able to plant in-ground 3 Meyers, 1 Trovita orange, and 1 Gold Nugget mandarin that are all from Four Winds and therefore on dwarf rootstock (BTW, does anyone know their rootstock - it isn't Flying Dragon, as far as I know...). My trees are anywhere from 1st year to 3rd year in the ground. So in answer to your questions:

    1) Watering: First year for all (in-ground) citrus, I was watering 5 gal 2x/week. Thereafter I've tried to decrease watering by (same volume) 1x/week for yr. 2, and 1x/2weeks for yr. 3, and 1x/3weeks/yr. 4, etc. I'm doing this in an attempt to be water-wise, but we'll see how successful I'll be in coming years. Someone across the Bay from me says they only have to water once every 4-6 weeks, so I'm doing the experiment to see (while all the while keeping John's advice of weekly watering for best fruit yield in mind).

    2) Fertilizing: The first year, I was using Miracle Gro's Miracid weakly/weekly, but have since switched completely to using GreenAll's Citrus & Avocado (14-4-8) fertilizer 3 times/year. To make it easiest on myself, I fertilize on Valentine's Day, Memorial Day, and Labor Day and follow the directions for quantity to apply based on tree age. I don't use GreenAll on my potted Meyer though - for this I use FP. Whatever fertilizer you use, citrus evidently take up N-P-K in the ratio 5-1-3, so it's best to look for fertilizers as close to this as possible. Also, you'll want to make sure you have micronutrients in your fertilizer, namely Fe, Ca, S, Mg, Mn, & Zn (to name a few) for most vigorous growth.

    3) Pruning: Probably best to not prune for a few years since you want to encourage leaf production for optimal growth of the trees and best fruit yield. Speaking of fruit yield, citrus are self-thinning of their fruit/flowers, so don't worry that you lose the great majority of baby fruit. Also, it's not uncommon for the fruit themselves to be suboptimal (dry, not the best flavor) in the first 2-3 years of production.

    4) Mulching: I'm very much an advocate of mulching in CA. First off, we're in drought country and anything you can do to help conserve moisture/water around the root zone is a positive. You can use almost any type of mulch, but I like the organic redwood/fir/any conifer bark since they break down and their acidity certainly couldn't hurt, but I also like to look of natural/tumbled stone as mulch. I've actually used stone on top of the bark as my mulch. I'm in agreement with John that mulch should be put no closer than 6 inches from the trunk - I expand mine as the trees age to at least 1 ft away.

    Some other things to consider for you:

    a) Tree planting depth: In an effort to prevent possible future problems with trunk rot you might want to plant your trees a bit higher on a mound so that the trunk/root interface sits slightly above the general soil level. Another way of saying this is to plant the trees on a mound and as the soil wears down over time, you'll start to see the root flare (like those thick roots exposed and extending from the trunk of an old oak tree!).

    b) Watering trough: I see that you're trees are on a drip system so might not be necessary, but for those who chose to water by hand, a basin around the tree created by mounding the soil a couple of feet or so round the trunk will allow the water to percolate downward as you water/fertilize.

    c) Pests: You will at some point encounter pests - anything from aphids, spider mites, thrips, citrus leaf miners, etc. If at all possible do use the most environmentally friendly alternatives instead of harsh poisons and pesticides. Think horticultural oil, need oil, etc.

    I've included a handy link to citrus care by the professionals from the University of California, and at bottom is also a nice list of additional websites, so do have a look.

    Good luck!
    Tim

    Here is a link that might be useful: UC Cooperative Extension citrus management link

  • arkberry
    11 years ago
    last modified: 9 years ago

    I only have a little more than a years experience with citrus, but I do have an in ground satsuma. I will tell you what I have done and ow the tree has done.

    I have watered just like any of my other outside plants and did use a small basin around the tree.

    I have used pine bark mulch to help with moisture retention.

    I am on a three times per year fertilization with a fertilome citrus product.

    I have not pruned at all.

    The tree has done very well outside (better than my potted ones). It has put on a lot of new growth and has about 12 fruits at the moment.

  • rhizo_1 (North AL) zone 7
    11 years ago
    last modified: 9 years ago

    The first thing that I noticed is that your trees appear to be planted too deeply....or you have piled a load of soil on top of the root ball for some reason. The top of that actual root ball should be slightly above grade.

    Never use peat moss as a mulch. There's really not much of a reason to use peat moss at all, unless you are strapped for an amendment to use when preparing an entire planting bed. I'm sure that you know that peat (or anything else) should not be put into the planting hole when planting hole-by-hole.

    It seems like the foliage pro would be very expensive to use as an in-ground fertilizer. There are so many granulated citrus fertilizers on the market that can be readily broadcast on top of the soil (or mulch) and watered in. Are your trees close enough to a hose bib that hand watering is possible (upon occasion)?

    Be SURE to check the soil all around your citrus to make sure that the drip system you've set up is watering deeply and is saturating the soil all around the trees, not just in one section. like I have seen drip systems do.

    I forget which state you are in, dandy. Clearly you live in one of the citrus producing locations, which means (hopefully) that your local extension office is a likely source for information for back yard growers.

  • oberci
    Original Author
    11 years ago
    last modified: 9 years ago

    Thank you so much to everyone for all the info!

    Johnmerr:
    Can you elaborate on "Foliar Fertilizer"? This is the first I'm hearing about this...What is the purpose of using it? Is it just sprayed all over the leaves or is it sprayed underneath? Can you recommend a good brand?

    TimSF:
    I'm definitely in SZ14 though quite close to SZ9.

    5 gallons 2x a week sounds like a LOT to me. Do you hand water? What kind of drip attachment should I put on to get that amount into the ground within a reasonable amount of time?

    rhizo_1:
    I will remove the excess soil atop the rootball and repost a picture so you can let me know if it is correctly planted. I didn't use peat moss but I did amend the soil prior to planting with a soil conditioner, so I hope that is ok. The trees are very close to a hose bib so I can definitely water by hand if necessary, especially if I am supposed to adopt a 5g/2x a week regimen, I will definitely need to water by hand. Also, I am in Sacramento, CA 95821 for reference.

  • timsf
    11 years ago
    last modified: 9 years ago

    In regards to watering, remember that citrus like consistency and DEEP watering followed by a pause before their next soaking; also remembr that citrus need a bit of water to develop all that juice! Yes I was/still do water by hand, and 5 gallons is about 2 watering cans for me. It may have been a tad much, but I figured that I was only doing for the first year anyway, and I wanted to make sure to establish them well that first year before tapering off on the watering. Especially in your warmer interior temperatures, for newly planted trees I don't think the amount in question is too much water at all. Nonetheless, you should judge by how your trees perform - if the leaves start curling or drooping, then it's time to water.

    I'd have to agree with the suggestion above that you should think of hand watering (at least for the first year which is really important in getting trees established). In this way you have better control over your watering and don't have to worry if your drip system is working/delivering correct amount of water. Then in subsequent years, I'd do the drip (but that's just me)...

    Tim

  • johnmerr
    11 years ago
    last modified: 9 years ago

    I personally would not worry about the level of the planting; it may make some difference in container growing; but your trees are in the ground and the only condition is you keep the bud union above ground. For my field trees I always plant them 1-2 inches deeper than the nursery trees; and on very young trees that added part below ground produces additional roots and strengthens the tree. I know there are a lot of people here who think it is important to have the root crown exposed; but the tree doesn't grow that way naturally, and I can find no scientific or physiological basis for leaving roots exposed.

  • timsf
    11 years ago
    last modified: 9 years ago

    Sorry, John, I'd have to disagree on disregarding planting depth.

    There seem to be a number of researchers at various Universities who've done studies showing there are risks to planting too deeply (link provided below).

    Since nature herself seems to readily exhibit adventitious root flare exposure (picture an ancient & majestic oak whose surface roots show quite prominently!), why not mimic accordingly? Seems worth it when there's risk otherwise, and you will (hopefully) have the tree in-ground for many decades to come...

    Tim

    Here is a link that might be useful: Research on effects of planting trees too deep.

  • johnmerr
    11 years ago
    last modified: 9 years ago

    Well, Tim, I guess we can just agree to disagree on this. I don't see that the research you cited makes any mention of citrus; and I don't know of any commercial citrus growers on the 5 continents I've visited who leave roots exposed. Further, I know from personal experience of planting Meyer lemons from the nursery that if they are planted a little deeper than the soil level of the rootstock, they do in fact produce additional roots and make the tree stronger. In the field, if roots are left exposed to the air, the tree will grow slower and will be vulnerable to chewing animals (rabbits, ground squirrels, etc). Having said that, I will say that I have NO experience growing maple trees, or oak trees, or a million other trees; I also have little experience with container growing; but for Meyer lemons planted in the ground,I have a mountain of experience.

  • timsf
    11 years ago
    last modified: 9 years ago

    John,

    May I ask whether you have any data supporting your (& other growers') belief that Meyers (or any other citrus for that matter) whose root flare are planted deeply confers any growth advantage (other than small mammal predation prevention) over those whose adventitious roots are exposed?

    If not for citrus, any supporting evidence for a different tree species perhaps?

    Honestly, I really would be quite keen to read the study. :-)

    Cheers.
    Tim

  • johnmerr
    11 years ago
    last modified: 9 years ago

    Data??? You are free to come to my farm and see for yourself. I only know from personal experience of planting small trees from nursery to field that, as long as you don't cover the bud union, the buried part of the rootstock will produce more roots... sorta like transplanting tomatoes and burying a part of the stem. I don't know if that would apply to an older tree; but I think not. I also do not see any advantage to leaving the root crown exposed; but I believe that if there were an advantage, somewhere I would have seen citrus groves planted that way. I will acknowledge that if there is an advantage, that would likely only apply to container trees; because the risks of damage from pests and cultivation practices in the field would outweigh any advantage. Again, I only have experience with citrus and inground production; but that is the situation presented by the OP.

  • rhizo_1 (North AL) zone 7
    11 years ago
    last modified: 9 years ago

    The short term effects of planting too deeply include the fact that trees (citrus and otherwise) will expend their valuable energy resources in developing new roots towards the surface...at the expense of growing roots laterally into the new planting area. Root systems require water and oxygen...if either of those commodities is difficult to access, a newly planted tree will spend its most important months in a survival mode, rather than in growth and development. Indeed, the struggle can be so detrimental that a plant begins to decline rather than prosper.

    We know from many years of research that the tree roots naturally grow in the shallowest part of the the soil system. Why? Because that's where the oxygen is...and usually most of the available water. Even a slight reduction in soil oxygen can result in a decline of tree root development and health and growth. Again, a tree will be forced to allocate essential resources to THAT effort...the struggle to get air. Dormant buds located in the buried root system will break dormancy in order to accommodate this requirement...and that is not a good thing.

    Woody plants have pretty organized systems. Their physiological responses to external forces are often quite predictable. And they are not as resilient as they may seem from the outside. They cannot respond to injury, recover from transplanting, grow more roots at the surface of the soil, produce flowers and fruit....AND grow a healthy canopy all at the same time.

    Now, if the receiving orchard soil is very porous, then there won't be much of a problem by burying the root flare an inch or two.

  • johnmerr
    11 years ago
    last modified: 9 years ago

    Here's a picture of some one year old Meyers planted 2 inches deeper than the nursery tree of 5 months.

    {{gwi:596119}}

    Works for me; but what I know comes only from my many years of trial and error... too many of the latter, sorry to say.

  • jakkom
    11 years ago
    last modified: 9 years ago

    I have to agree with John. None of our 3 Meyers were planted so carefully as to leave the root crown exposed, and anyway that was 10 years and a whole lot of annual mulching ago.

    All of mine are flourishing, and if you do a search on my screenname the latest photos will show up on one of these threads.

    I feed monthly, along with 2x or 3x/yr 3 gallon bucket of liquid fish emulsion and liquid iron diluted with water, tossed over the plant. Do NOT do this when the heaviest fruit harvest is getting ripe, as it will discolor the peel if the weather is sunny.

    If I think the Meyer needs that extra feeding and it's too near main harvest (Dec-May), I pour it more carefully into the soil.

    I may be the one mentioned who waters once a month. In the Oakland hills I'm on the edge of the fog belt and it doesn't get super-hot except a few times a year. Your red grapefruit's leaf curl seems thirsty to me; my Meyers only do that when they're getting a little too dry.

    ALWAYS let the soil dry out between watering, but if you don't want to be watering every week I would strongly suggest you mulch those citrus out past the tree line.

  • timsf
    11 years ago
    last modified: 9 years ago

    Hi guys,

    I wanted to pass along an e-mail response I just received from Dr. Toni Siebert on the question of whether there were any negatives we should consider to planting citrus too deeply.

    Dr. Siebert works with Dr. Tracy Kahn at what is arguably the premier citrus research center in the world (the Citrus Experiment Station at UC Riverside). The institution has been planting trees since the early 1900s. Here is Dr. Siebert's reply:

    Hi Tim,
    In our experience, planting citrus trees too deeply in which the soil and any moisture covering any portion of the trunk is a disadvantage. Exposing the trunk to constant moisture by planting the tree too deep causing water ponding or waterlogging of roots, has been known to be associated with the invasion of root tissue by wood rotting organisms, usually Phytophthora or Fusarium fungi.

    The general rule when we plant our citrus trees is to only plant the tree to a depth at which the tree can set evenly with the soil line, so the depth depends on the size of the pot the tree is being grown in. In our citrus classes, the planting instruction that are given to students are as follows:

    "1. Dig a hole that is 2-3 times as wide as the diameter of the container holding the tree. While the tree is in the container, find the area where the stem merges with its root system. Measure from this area to the bottom of the container. Dig the hole as deep as the measurement. Save the soil from the hole to use as backfill. If the hole is deeper than the measurement, prior to placing the tree in the hole, backfill with enough soil to hold the tree slightly higher than the measurement. Firmly press the soil before setting the tree on it.
    2. Position the tree.
    Carefully remove the tree from the container, supporting the rootball. Place the tree in the hole and center it. Check the hole depth. It is most important to plant at the same height or slightly above the height of the soil level in the nursery container. Cut any circled or kinked roots. Loose roots should be positioned facing down in the hole.
    3. Fill the hole.
    Remove any rocks, grass or debris from the dug-up soil. Break up clods. Add backfill soil, firming it around the lower roots by hand. Continue filling and firming 4-6 inches at a time. Press gently with the top end of the shovel handle. Soil should be firmly, but not tightly packed. Create a basin to hold water that is just a little larger than the rootball. Build and compact the edge of the circular basin to a height of 6 inches. Pull out all weeds in the basin.
    4. Water
    After the tree is planted, fill the basin with water. Check the original soil line one last time. If the tree does settle, now is the time to move it back to the correct position with soil level against trunk at the same level that it was in the container."

    Best,
    Toni Siebert
    toni.siebert@ucr.edu

    Although there are root stocks that are more resistant to Phytophthora (e.g. Trifoliate orange) rendering this possibly as less of an issue, there is evidently no cure for Fusarium fungi. Therefore, I would still practice caution by heeding the above planting guidelines of these researchers.

    jkom, I do have a question for you. Since I recall you mentioning that one of your Meyer trees was actually derived from the seed of a fallen neighbor's fruit that had successfully germinated, I'm wondering if you've ever seen the trunk/root crown interface exposed? I ask this since I'm curious what is the natural exposure of a citrus (in this case a Meyer) tree's roots when it grows unaided by humans. If you currently do not see the upper adventitious roots, since you're in the Oakland hills, could erosion have buried the trunk over the years?

    Cheers,
    Tim

  • johnmerr
    11 years ago
    last modified: 9 years ago

    Arguably is the right word for UCR's research. In my experience they are aloof, quite out of touch with growers and processors, and definitely overrated. I have gotten much better information and support from West Australia and from Texas A&M Kingsville Citrus Research Center in Weslaco, Texas; they both work very closely with growers and processors, and they actually know what works in the real world and not only in the laboratory.

  • blazeaglory
    11 years ago
    last modified: 9 years ago

    John your trees look great! How long have you been growing in Guatemala? That soil looks really healthy...

    And to comment on that letter from UCR. It looks like they just cut and pasted it off of a typical grow website. I always wondered when they say "It is most important to plant at the same height or slightly above the height of the soil level in the nursery container."...What if the original nursery planted the tree too deep in the pot? I bought a peach tree one time and when I took it out of the pot the soil was about 3 inches above the bud union!! So from UCR's advice I should have planted it as it came in the pot right??? HELL NO! 3 inches of bud union under the soil is a no no for me. Anyways, my meyer lemon is planted with the crown about 3 inches down under the soil with the bud union about 5 inches above. My tree is growing fine and is actually growing better by the month. Well see how it looks in 10 years...Lol I sometimes dig lightly down to check the crown for girdling and problems but almost 2 years in ground and nothing yet.

    And for fertilizer for backyard home growers I recommend all organic. I mean, its your soils natural state. And earthworms and beneficial bacteria dont like chemical salts like MG. I can see using chelated fertilizers on a large scale for convenience and cost but for a home grower just keep your soil healthy with compost and organics. Just my 2 cents:-)

  • cebury
    11 years ago
    last modified: 9 years ago

    About planting too deeply: it's like other things, you can take chances do things the wrong way and many times be OK, sometimes even succeed. I haven't exercised in years and eat high carbs constantly (sugar cereals and of course, FRUIT) and recently a full physical found me completely healthy (except for one genetic chronic pain condition). I was shocked none of my labs were out of range, esp. the "diabetes check".

    A lemon in my backyard is planted WAY too deeply, it looks more like the previous owner created a raised bed along the fence line after the lemon was already established, basically burying the crown under 18" of soil. As with most lemon/grapefruit, I can't get that thing to slow down, despite Root pruning with corresponding branch pruning.

    Lots of factors involved in rot, as discussed above. But every tree I plant myself, I pay close attention to the crown.

  • blazeaglory
    11 years ago
    last modified: 9 years ago

    Dandy did you get those trees from Clausen Nursery in N San Diego?

    Also, all these recommendation are good for chemical chelated growing but if you want healthy soil I recommend using organic nutrients and compost with a pine chip top cover or something similar. You will get good results with "chemicals" but eventually it will deplete your soil of all of its natural bacteria and natural nutrients. With organics you keep the soil web healthy by promoting good organic matter and bacteria growth. Not to mention very happy fruit trees:-)

    Im not knocking chemical fertilizers but I am keeping them for my potted plants. For the soil, I use nothing but organic now and I am starting to see a return of earthworms and good things.

    After almost 40 years of using nothing but chelated fertilizer, such as Miracle Grow, my soil had become pretty sterile and required weekly feedings to keep anything healthy. Now my soil is healthy with compost and organic fertilizers and I only have to feed 3 times a year. Plus the results, I think, are much better.

    The soil is where everything begins, not the roots. Keep your soil happy and your trees and fruit will follow:-)

  • jakkom
    11 years ago
    last modified: 9 years ago

    TimSF, sorry it has taken me so long to get the photos of my Meyers along with close-ups of their trunks, including the one that sprouted from seed. Mea culpa!

    I put the photos in a separate thread with explanations. Let me know if you have any other questions.

    Here is a link that might be useful: jkom51's Meyers and trunk photos

  • oberci
    Original Author
    11 years ago
    last modified: 9 years ago

    Blazeaglory, sorry for the delayed response, it's been a busy summer! So do you keep pine bark as a type of mulch on the soil near the trees and then 3 times a year add organics?

    Can you maybe describe your routine in more detail, suh as what organic nutrients you add, when, and how? Also, what is your watering schedule like?

    I'm completely on board with focusing on soil improvement first, I'm just not sure how to go about doing that correctly, how long it will take to get the soil healthy, etc. Right now i feel like the soil all over my yard is one hard, hot, dry, nutrient free wasteland :( Perhaps I need to start a new thread on that topic :/

  • janehoya
    10 years ago
    last modified: 9 years ago

    We live in San Francisco and our back patio cement was improperly graded so all rain water rushes towards our home/foundation. We are ripping up some of the cement and the plan is to create a hole away from our foundation and fix the grading so that water collects in that hole.

    We'd like to plant a dwarf eureka lemon tree in that hole but based on what I've read in this thread I wonder if it will be an issue that rain water will collect there.

    The lemon tree will get morning sunshine as it faces an easterly direction.

    How large should we make this hole in the ground? Our gardener recommended 18" round but I was thinking more of 26" square.

    Many thanks for your input.

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