How do I grow thriving Gardenias (G. jasminoides, G. augusta)?
Mehitabel wrote the following post entitled "One season's lessons about growing gardenias"
Posted by mehitabel z6 MO (My Page) on Wed, Sep 24, 03 at 20:20
What I have found is that gardenias for the most part are vigorous plants that get fat and happy in pots if conditions are the least good. I wanted to share my experience with them this summer, because I was very much hesitant to even try one after reading all the stories of slow decline.
But my experience has not matched that, except with a couple of plants, and I hope this will encourage other people to try them. The blooms are beautiful and fragrant, and cut well.
The one I bought from HD (the first) has not done well, but I attribute that to the source-- several plants in one pot forced into bloom for valentines day. These are bound to drop buds, sulk etc when you get them home and maybe never get going properly.
I found the best plants for getting established quickly as pot plants are vigorous varieties like Belmont or Miami Supreme. Also, potbound plants are harder to get established and you need to check the rootball to make sure they are getting their roots into the new soil. Naturally, in-ground plants would be another matter.
Put them in a pot no more than 2" bigger than the rootball. Use a clay pot if you can. They keep the roots cooler, and I have always found roots in clay to grow much better. Let the roots fill up the pot (but not potbound) before repotting. You can tell because it starts to need water more often.
A good peat based potting soil (I use moisture control miracle gro) with timed release fertilizer and dry ironite in it gives it a good environment. You can add peat, but I've had some without added peat that did fine. The timed release fertilizer evens out the fertilizer, and the dry ironite gives a lot of micronutrients and prevents the leaves from getting chlorotic. You can give it some bloom-booster (10-50-10) maybe once a month or so.
I also give mine epsom salts (source of magnesium) and liquid iron chelate once a month or so to supply micronutrients. You can give it oftener than that if you need to. Keeps the leaves beautiful.
Outside in summer, they get just the right amount of humidity and will thrive. They happily take sun til app 2 in the afternoon all summer.
If you get aphids, just hose them off every couple of days for 3 or 4 times. Or just wash off with soapy water.
Be careful of overwatering, overpotting and overfertilizing. I tend to overwater, so I use a moisture meter to test need for water, or stick your finger in and water when the soil starts to dry. But don't let them get too dry, either. Gardenias are susceptible to root disease, and any of the above no-no's can get it started.
Inside in winter they are going to get stressed because the humidity in the house and perhaps the light you can provide is too low. The way to deal with this is to keep them outside as much as possible. They can be kept out at...