Prune or Not Prune on Transplant?

Discussion in 'Citrus' started by Junglekeeper, Oct 16, 2005.

  1. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

    Messages:
    5,997
    Likes Received:
    612
    Location:
    Vancouver BC Canada
    When transplanting a bare-rooted citrus tree, would it be better to prune back the tree or to just let it be? Does the answer depend on whether the tree is showing signs of stress or not?

    Keep in mind a tree stores large energy reserves in its stems and trunk. The question then is whether the tree would benefit more from this reserve by not pruning or from reducing the load on the root system with pruning?

    Assume the parts being pruned will be pruned anyway at a later date because of damage, poor placement (e.g. crossing branches), or reshaping.
     
  2. Millet

    Millet Well-Known Member 10 Years

    Messages:
    1,698
    Likes Received:
    5
    Location:
    Denver,Colorado USA
    In citrus the leaves are the principal storage of the plants energy reserves. In addition to their photosynthetic role, citrus leaves function as storage organs. The principal storage carbohydrate (energy reserves) of citrus is starch but also considerble amounts of soluble sugar. Whereas leaves of annuals show a clear daily cycle with all energy reserves that were generated during the day being removed during the night, citrus leaves retain most of their starch and only slight diurnal translocations are evident. Therefore, if you remove the leaves by pruning you are removing nearly all the food reserves that the tree will require after being transplanted. You should only prune dead or broken roots. Transplant the tree a little higher than it grew in the nurseryto prevent rot. Be sure to keep the graft at least 3-4 inches above the containers soil level. - Millet
     
  3. Ron B

    Ron B Paragon of Plants 10 Years

    Messages:
    21,304
    Likes Received:
    810
    Location:
    WA USA (Z8)
    Rather than a load on the roots, an intact top supports root recovery. This is not peculiar to citrus. Whitcomb, Establishment and Maintenance of Landscape Plants calls the introduction to his chapter 'Top Pruning at Planting', No Support for an Old Practice.
     
    Last edited: Oct 17, 2005
  4. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

    Messages:
    5,997
    Likes Received:
    612
    Location:
    Vancouver BC Canada
    Interesting. Thank you both for your comments. So the current practice is to keep the growth and prune only when the tree has recovered? When did this turnaround occur? This is analogous to the current practice of not applying pruning sealants.

    Ron_B, surprised to see you in the citrus forum.
     
  5. Ron B

    Ron B Paragon of Plants 10 Years

    Messages:
    21,304
    Likes Received:
    810
    Location:
    WA USA (Z8)
    You prune to train (shape) the top - if desired - as an independent operation from transplanting. Brickell/Joyce, PRUNING & TRAINING (DK Publishing) have 3 pages, with photos on how to handle citrus.

    Whitcomb probably first noticed cutting back tops of transplanted trees producing an inferior result in the 1970s: "The first experiment to study the question was set up in the spring of 1978 to evaluate effects of top pruning and fertilizing at planting time..." (Establishment and Maintenance of Landscape Plants, 1987 (1991) edition)
     
  6. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

    Messages:
    5,997
    Likes Received:
    612
    Location:
    Vancouver BC Canada
    I should have been more precise with my wording: "...[proceed to] prune only when the tree has recovered [from the transplant].". Thanks for the reference; the photocopies I have on pruning citrus likely came from this book. The actual act of pruning is never quite as shown though - I think it's more an art than science.
     
  7. Millet

    Millet Well-Known Member 10 Years

    Messages:
    1,698
    Likes Received:
    5
    Location:
    Denver,Colorado USA
    Actually Junglekeeper, I would never ever prune a new citrus tree, and only very rarely would I prune an older citrus tree. During the first years, there is no need to prune, even the vigorous sprouts, since research has shown that any cut to a young tree reduces root growth. This is due to the equilibrium between the foliage and the root system. A citrus tree is a biological unit. Even on older citrus trees pruning should be restricted to a selective canopy thinning only, or to keep the canopy low. The choice of branches to eliminate is based on the concept that any space within the canopy must be covered by only one branch. It is not wise to let surpus branches occupy the same aerial space. Also, thining must not deplete any canopy sector. Vegetation free canopy spaces must be avoided since they reduce yield. Suckers should only be kept if they occupy free spaces. After a few years they bear fruit, but all interior suckers must be cut. Pruning of citrus is either practised rarely or not at all. Unpruned trees come into bearing quickly and yield crops for many years. - Millet
     
  8. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

    Messages:
    5,997
    Likes Received:
    612
    Location:
    Vancouver BC Canada
    Thanks for the advice, Millet. The tree that I bought recently has recovered from its bare-rooting some 2.5 months ago. So my question is actually a hypothetical one but your recommendations will be useful.

    At this point I've cut off growth that was damaged, crossing, or pointing into the center and none of them were major branches. I salvaged the better pieces and propagated them as cuttings. It worked out pretty well as now light can actually penetrate the center of the tree and yet it still has a full canopy.

    It's wasn't the best looking tree when I got it - up here you have take what you can get your hands on. It was completely lopsided with no growth on one side (not an exaggeration) and bunched up growth on the other. After the light pruning and some work a la bonsai-style wiring, it's looking much better. The tree must have been growing in an awkward position in a confined space.
     

Share This Page