Gardenia with yellowing leaves

Hastings, FL(Zone 9a)

I planted a young gardenia bush last spring. It did wonderfully and produced many flowers. It was covered in the frosts this winter but in the spring it began to have leaves turn yellow. I plucked or cut the yellow leaves off and it happened again within a few days-a week. Once again I removed the yellow leaves and it is doing it again. I fertilized in early february with an all purpose miracle-grow fertilizer. Also there is a mimosa tree to the side of the gardenia which received a couple of fertilizer spike, one of which was on the same side as the gardenia.
Is there something I am doing or not doing to make the gardenia unhappy? I appreciate any advice and thank you in advance!

Dublin, CA(Zone 9a)

Can you post some pictures? It would help to know if the leaves are solid yellow, or are they mostly yellow but around the veins it's still green. If it's yellow with green veins, don't pull the leaves off--it's a sign of iron deficiency which can come about two ways--one would be it just needs iron (which some fertilizers have), or your pH is too high. Gardenias need acidic soil, if the soil is too alkaline then they can't take up the iron that might already be in the soil so you will see these symptoms.

Hastings, FL(Zone 9a)

thanks Ecrane. I will go out and take a few pictures right now. In the past week or more I've had problems posting pictures but I'll try again.
As for iron I do know that my well water is high in iron. Let's see what the pictures say...

Hastings, FL(Zone 9a)

These are pictures I just took. I hope we have a solution!

Thumbnail by yeye5 Thumbnail by yeye5 Thumbnail by yeye5
Broward County, FL(Zone 10b)

The leaves look like iron deficiency, could be another one like magnesia,too. Try a combined fertilizer with iron and magnesia and all the other necessary nutrients.

Hastings, FL(Zone 9a)

Thanks for the feedback. My water here is iron heavy so perhaps it is magnesium deficiency? I will look for magnesium heavy fertilizer. I was just worried about over fertilizing too. Do you have any recommendations for products I might look for?

Dublin, CA(Zone 9a)

I would check your soil pH first--if your soil pH is too high the plant can't absorb iron that might be present. Gardenias prefer acid soil also so if your soil is on the alkaline side I would definitely address that before you do anything else. If the pH is fine then I wouldn't add any more regular fertilizers--since you already fertilized, if you go adding more fertilizer (particularly with nitrogen in it) you could burn the plant's roots. If it is deficient in magnesium then I would look into something like Epsom salts--that will add Mg without all the other stuff that comes in the fertilizer you already gave it.

It's also probably worth checking your watering. The leaves that are yellowy-green with green veins are consistent with iron deficiency, but the leaves that have gone completely yellow could be something different. Gardenias are a bit temperamental about watering--they don't like to dry out too much but they also don't like to sit there in heavy wet soil so it's a very fine balance.

mid central, FL(Zone 9a)

those spikes are useless (imho). when you do decide to feed again, try something granular and all purpose or one for azaleas (more acid). whatever you use, make sure it isn't just N-P-K. get one with all the micro-nutrients added. ace carries a good selection for florida gardeners. our florida sand is deficient in almost everything......:-(

Hastings, FL(Zone 9a)

Thank you both. I will figure out how to test the ph of my soil. I may be over watering too since other plants near the gardenia seem to be thriving on lots of water. I am going on monday to look for test supplies and mag fertilizer. I do have epsom salts but I see first I have to test the ph. I appreciate this advice!

Prairieville, LA(Zone 9a)

Yeye5, you can also use Ironite to add iron and trace minerals. It is a 1-0-1 NPK and will not burn the plants and has 9 additional minerals.

http://www.ironite.com/

Also, here is an interesting article that touches on the things Ecrane told you about pH and too much water.

http://www.ehow.com/way_5849665_rusty-water-nourish-plants_.html

Hastings, FL(Zone 9a)

Thank you for the new links. I went looking for the magnesium fertilizer and was told it was all sold out. Since I was riding in a taxi I decided not to go all over looking at other stores. I will check the new links and hopefully be able to aquire the right products. Thanks again.

Hastings, FL(Zone 9a)

That was truly helpful. I am going to see if I can buy ironite online.
The reason I mentioned the iron in the well water is simply because , for example, white tile or porcelain tends to get red-stained if left untreated in my house so I assumed that iron was the same kind of iron...silly me.

Beautiful, BC(Zone 9b)

I'm with ecrane3 - check the PH of the soil first. If that's out-of-line, it causes other problems.

Prairieville, LA(Zone 9a)

Glad it was of use to you. You can usually find ironite at most garden centers, Wal-Mart, Lowe's Home Depot, etc. or on-line.

Hastings, FL(Zone 9a)

Thanks. Walmart had just sold out. Next question: how do I test the ph of my soil?

Beautiful, BC(Zone 9b)

Take a look at this video: http://www.ehow.com/video_8473283_test-ph-garden.html

Magnolia, TX(Zone 8b)

Needs a litmus plant, chuckl

Dublin, CA(Zone 9a)

There sort of is one...Hydrangea macrophylla blooms will be pink in alkaline soil and blue in acid soil. But, there are much faster ways to test your pH than planting a hydrangea and waiting to see what color the flowers turn!

Magnolia, TX(Zone 8b)

Was a tongue in cheek joke, chuckl, knew there was one tho,

Hastings, FL(Zone 9a)

well I watched the video and I found that I already had a little store-bought tester kit from a few years ago, unopened so I trust it will work fine.
Before finding this kit, and because the gardenia was looking yellower and yellower I ended up digging it up and moving it to a different area. This idea came because the mimosa tree that I've been bending/sculpting was taking over the area with its roots. Maybe that was relevant, maybe not. When I dug the new hole I filled it with potting soil and then replanted the gardenia. I will test the soil where it was and also test the soil where it is. I'm guessing that the move is traumatic but the new soil is beneficial. (I did this yesterday).. Now testing the soil will be helpful in the long term.

On a side note, the hydrangeas that I planted last fall came to me with white blooms. I over pruned them in the winter--my bad. They are growing back nicely but because I wanted hydrangea blooms this year I bought another one. This plant (and All of the hydrangeas that were for sale) has pink blooms.
I am guessing that the nursery used different soil for these. One question: how many times will a hydrangea bloom in one spring-summer-fall season? And is it safe or practical to play with the soil around it to change the color of the next blooms?

Magnolia, TX(Zone 8b)

Most folks who want hydrangea plants watch their soil and VHF it to keep it the color they wanted, just do it in steps

Dublin, CA(Zone 9a)

Most of the hydrangeas that have the pink or blue flowers bloom on old wood and will only bloom once per year. There are some reblooming varieties in the Endless Summer and Forever and Ever series which will rebloom. Those would have come with a tag listing the name and if it doesn't have one of those trademarks on the tag then it's most likely not a rebloomer.

Hastings, FL(Zone 9a)

Thanks.
New questions: the hydrangea I bought says it blooms late summer to early autumn. (It also calls the plant a hydrangea paniculata). Because of buying it with these early blooms, will it not bloom again this season (it sees like the answer is above...?)
question 2 is: how can I buy some of the varieties that bloom several times per year?

Dublin, CA(Zone 9a)

Hydrangea paniculata blooms on new wood, so it's possible you could get some more blooms later in the year. I don't think you'd typically see blooms on them this early, although your climate is very different than mine so maybe they bloom earlier there. Most of them have white blooms, some have pink but this species doesn't change color based on soil pH, so if you have a pink one it'll be pink regardless of the pH of your soil.

As far as the pink/blue ones that rebloom, look for ones in the "Endless Summer" and "Forever and Ever" series. Those are all reblooming cultivars of H. macrophylla; they bloom on both old & new wood so you'll get some blooms earlier in the year on old wood, and then some more later on newer growth. I expect your local nurseries would carry some of them, although if you have your eye on a particular one you may have better luck online. The H. macrophylla's are the ones that change color due to soil pH--pink in alkaline soil and blue in acid soil.

I wouldn't worry too much about reblooming though--hydrangea blooms last for quite a long time so even if you get one that only blooms on old wood, you'll be able to enjoy the flowers for quite a long time. The main benefit of the reblooming cultivars is for people who live in colder zones where the flower buds on old wood tend to get zapped by spring cold snaps. For people in those zones, if they want to have flowers they need to take the time to protect the shrub over the winter so that doesn't happen, but with a rebloomer even if the buds on old wood get zapped, it'll make more buds on the new growth and still bloom without having to put effort into protection.

Hastings, FL(Zone 9a)

Sorry for going missing! I had a terrible toothache and huge abscess that took 2 weeks to deal with...
I did the Ph test and it is very high just as everyone suggested. Now that I know this, what can I do locally to bring the ph to a better level? I may try simple "home remedies" like used coffee grounds. I sure hope I can make this plant happier.

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