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katkin_gw

Pruning Hibiscus

katkin_gw
17 years ago

Years ago I read in a FL gardening book to hard prune hibiscus in Feb. Does anyone do this or recommend it? Would it help with gall midge? I used to do it back then, and didn't have much trouble with the gall midge. I haven't done it the last few years and have been having a problem with them, especially this year.

Comments (10)

  • katkin_gw
    Original Author
    17 years ago

    Oh, and is anyone allergic to them, my DH seems to be.

  • longwoodgradms
    17 years ago

    If you're in zone 10 you can prune heavily any time of year. Last year, as a result of a very badly infested gall midge infestation, the hibiscus were cut to 12-18" in mid October (just before WIlma).

    Then, the stub shurbs were showered in soap and oil to kill any bad stuff lingering. Then, as the new leaves emerged, soap was used as needed to ensure "clean" new growth. By mid December, many cultivars were flowering again.

    I'd do the prune in spring, too, but I"ve noticed that new growth in March and April is really attractive to aphids and white flies. The gall midges seem to lessen (as with all the other pests) from Nov-feb. You just have to be ready for them as the heat of March takes over.

    When you mention "years ago"--what do yo mean? Gall midge was introduced into Fl in the mid 1990s and its getting very progressively worse. 3-4 years ago in W. Palm it was just starting, now it's pretty widespread, and I see you've got a convincing problem with it up in St Lucie county.Each year you hear people in different parts of the state start complaining of the bud drop, so you can watch the spread around the state.

  • Lynn_Z9
    17 years ago

    Dumb question, but I just planted a new hibiscus so I am curious.
    What is gall midge?

  • longwoodgradms
    17 years ago

    lynn, not a dumb question in the least! SO many gardeners will be doing everything perfectly with their hibiscus and the gall midge will blind side them and all their hibiscus will stop flwoering.

    Gall midge is the larva of a fly. The fly lays her eggs on the hibiscus, and the larva (the midge) attacks the flower buds by burrowing into them and effectively destroyed the veins that carry water and nutrients to and from the developing bud.

    Once the bud's vascular tissue is "cut off" by the midge, it yellows and it drops to the ground. Once on the ground, the larve burrows out into the soil to complete it's transition into an adult, and then mates nad lays eggs back on the juicy hibiscus shrub above.

    This is why it's important to either pluck off any yellowing buds from a hibiscus AND any/all that have fallen off the shrub and lay on the ground. It helps disrupt the lifecycle. That, and horticultural soap sprays can help you stay ahead of the battle. But, if it gets out of hand, you'll need Orthene or Isotox, or simply use a broad systemic insecticide.

  • katkin_gw
    Original Author
    17 years ago

    LOL, we moved to FL 10 years ago, and I didn't know anything about gardening here and didn't have a pc. So I read everything I could, but as you know what is done in Jax, isn't necessarily right for PSL. I used to prune the hibiscus hard every Feb and didn't have a problem with gall midge. I stopped doing that as I like the taller bushes as a screen for the pool and now I have midge. So it seems about the time I stopped pruning hard is when the midge started. So when I said "years ago" I meant ten years. :) It did sound like I meant much more, after I reread it

    Would malathion oil work?

  • longwoodgradms
    17 years ago

    AHHHHHHHHHH! Never use malathion on a hibiscus. It will kill the plant! Words to live by with hibiscus! Tatoo it on your arm. ;P

    Soap is the "least harmful/safest for ladybugs, etc" solution along with removing fallen buds.

    If you really wanna "cheat" and it's OK (hibiscus and roses are HIGH maintenance), use a systemic insecticide. That helps A LOT (such as Bayer Advanced or Triazicide). Some people are anti-systemic, but when used as a spot treatment for ailments, I don't see it as so horrible. Some times tough problems need some bigger guns.

  • katkin_gw
    Original Author
    17 years ago

    Glad I asked, I never really use much at all. But a neighbor moved and gave that to me. It said it was good for citrus, so I thought it might work. I did cut them back some and am still picking off the yellow buds. A few have bloomed already so I'll see how it goes. I may just hard prune them after all. Thanks for you advise. :)

  • pepper4365
    17 years ago

    I live in New Jersey and this is my first winter with Hibiscus. The two kinds that I have planted is Copper King and Sweet Caroline. My question is do I cut them back in the spring and if so how. Or do I just leave them along and let nature take its coarse?

  • steveflorida
    16 years ago

    I had a home built in 12/2005, in central Florida (east coast). The hibuscus plants were planted in 03/2006. They have been trimmed, but not pruned. The plants are starting to be top heavy with blooms and sparce towards the base. My question is how far down to prune them? Leave 1 foot of stem? Cut more than that?
    Also, has anyone ever used a hedge clipper (electric) on them with good results?
    Thanks for any assistance.

  • early_bird_2007
    16 years ago

    Steveflorida, I cut my h. mercilessly twice a year with electric hedge tool. It doesn't mind, only getting thicker. First time it was about 3 feet tall and I cut 1/2 of it.

    Maria