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Gardenia has high pH in October what do I do?

springlover
13 years ago

Hi, I am new to the site & growing a Gardenia. I picked up a Gardenia Augusta recently. At first it was outside and I had to deal with aphids, I think (small purplish grey bugs. I live in S.W. MI so now I have brought the plant inside, after treating with a spray & keeping it in the garage to see if the bugs were under control. I think it has gone through the normal enviro. shock change because a lot of the leaves in the center of the plant turned yellow and fell off. I have tried to read as much as possible to figure out on how to care for this plant. I recently checked the pH and found it was over 7.0 around 7.3-7.5. I understand that it needs to be between 5.0-6.0 to be happy. I purchased some MG Azalea plant food (acid fert.) after reading diff. articles. I gave it the right dosage last week and it still has a pH over 7.0, maybe higher in some areas. I need to say that the plant has new growth in several different locations and it seems to have stopped the yellowing and losing of leaves. I am trying to watch the watering and it is next to a south facing window. Back to the high pH since then I have tried a little bit of left over coffee, some grounds and vinegar and to gal of water this week to try an lower the pH. I have hard well water so I figured the vinegar might work, but it is still around 7.3-7.5. Should I still keep trying to lower the pH even though it is October 20th because my understanding (from articles)was that it won't survive with such a high pH. The MG says every 2wks to apply do I reapply? Even though I know it is not the growing season or just let it go or lower the pH? Is the pH important this time of the year? And how and with what frequency can I apply something to get it to a healthy pH? It is also still in the same plastic pot form the store, It sounded as though I should wait to transplant I was thinking in the spring or should I now? I noticed some more aphids(maybe) also this week on one leaf that I wiped off and now I am contemplating taking the plant outside in the sun to spray again to avoid infestation of all my indoor plants and the rest of that plant, which looks healthy. Thank you for any advice in advance.

Comments (6)

  • mehitabel
    13 years ago

    Springlover, the thing about gardenias is that they are highly susceptible to root decay if "overwatered" ie watered too often, or if let to dry too much. This is very likely to happen in retail stores where plants are cared for by truly ignorant sales personnel.

    That is what I would suspect is happening to your new gardenia. Whenever you buy a new gardenia, it's possible it's already been subject to root decay. If the problem is root decay there's no amount of fussing over pH, fertilizer or anything else that will help it.

    Once root rot begins, the pot becomes too big for the smaller root mass and the medium stays wetter and wetter, causing more and more root -- a death cycle for the plant.

    For this reason, I would take it out of it's pot and check the roots. I always repot a new gardenia. This doesn't necessarily mean a bigger pot, but it does mean that I get to look over the roots and put it into a right-sized clay pot. This might be a *much smaller pot*. You want one that is maybe half an inch bigger than the roots.

    I personally think your worry about PH is misplaced. First things first: get it into the right environment for healthy roots. Put it in a pot just barely big enough for the roots. I use Miracle Grow Moisture Control potting mix. It is peat based and should give an adequate environment.

    Aphids also are very common on gardenias. The thing to remember about aphids is that they give birth to *live, pregnant* young. That means where one aphid is, there will be thousands in a few days. You have to spray every three days or so for maybe four times to get them all. I spray with one hand and use my other hand to wipe the aphids off so there won't be little ones surviving underneath the carcasses. And definitely you have to spray more than once.

    Take care of the roots and the plant will be okay.

  • springlover
    Original Author
    13 years ago

    Mehitabel-

    Thank you for your advice! I'll get it repotted in a suitable container with the moisture control medium. Does it matter if the pot is plastic or clay?

    I just checked the water content with a meter this morning and it seemed that the first 2-3in were dry and 3.5 and lower where moist. I did give it a drink because of that with the acid fert. Should I stop with the fert. because I am now not worried about the pH right? And how often should it be watered in October and the coming months? I have read different opinions on this. What do you suggest?

    What if my roots are unhealthy ie.(mushy) should I cut off what I can or let it air dry? What is the best thing to do if it comes to that?

    I did spray off the gardenia with water and then rose & flower insect spray(contains pyrethrins, canola oil & botanical insecticides)I think at least 3 if not 4 different times before I brought it inside. I thought that would of been enough but I guess not due to finding the one leaf with bugs, since I have seen that one I have not found anymore but it is supposed to be in the 60's today, so I'll get it back out side and spray it again. I also didn't know I could spray every 3 days so thanks I waited a bit longer in between applications. Again thank you for the advice! I do appreciate it.

  • lou_spicewood_tx
    13 years ago

    Visit container gardening forum. Lots of valuable information on how to grow plants in the pots. The thing is that peat moss isn't used in large quantity. Mostly pine bark fines and a little bit of peat and turface.

  • springlover
    Original Author
    13 years ago

    lou midlothian-

    Thanks for the info on the forum I'll go check it out. So MG doesn't have the desired peat moss. I'll look for a mix that does.

  • mehitabel
    13 years ago

    Hi, springlover

    A clay pot is definitely better for gardenias or any plant that's highy susceptible to root rots. The clay "breathes" and maintains a better mix of moisture and air. You will see -- roots in clay are fabulous.

    Dry on top, wet at the bottom-- that's the formula for root rot, all right.

    Don't let roots dry out completely. If your roots are compromised, trim them. However, note that brown roots may not be rotten, they might just be stained by the medium. Cut off what's mushy, and get rid of any soggy medium. Be especially careful that the pot isn't *too deep*. If it's more than an inch or two deeper than the roots, put a few of those white styrofoam peanuts at the bottom. Cutting off a few healthy roots won't hurt a plant as long as it's got plenty of roots.

    Don't fertilize til your plant is healthy again. You need to cut back fert in the winter anyway, or you'll get weak, leggy growth. But definitely no fert for an ailing plant.

    If you're plant happens to be a gonner, don't blame yourself-- we sometimes just get plants that aren't healthy from an ordinary retailer, as I said before. But definitely try again. Gardenias aren't hard if you can start off right with a healthy one.

  • springlover
    Original Author
    13 years ago

    Good Evening mehitabel-

    Thanks for getting back with me. I'll transfer it into a smaller clay pot. If I have anymore questions I'll get back to you. Hopefully there isn't any root rot or not that much.