Help with yellowing Gardenias?

I have a Certificate as a Master Gardener, and Horticulture was my major in college.

The condition you describe with your gardenias sounds like "chlorosis." The plants are in need of NITROGEN.

Give them an acidic fertilizer, such as is used specifically for Azaelas and rhododendrons. Gardenias need an acidic soil.

Your gardenias need a lot of TLC at this point. Here's what I would do for them:

1) Make sure they are in indirect light, or at least where they can get about 3 hours of shade per day.

2) Water them well BEFORE applying high-nitrogen fertilizer, and water them well AFTER applying the high-nitrogen fertilizer.

3) Since they are already stressed, do not prune them.

4) Do not give them anything except high-nitrogen fertilizer until green leaves come back and fill the plant. Once recovery has taken place, feed only high-nitrogen according to package instructions. Bandini and Vigoro are the best brands. Do not give them iron---they are chlorotic and need NITROGEN. Gardenias like to have used coffee grounds worked lightly into the soil, if you can manage it, once a week.

I hope it's not too late for your gardenias. If it is, buy a couple more plants and start over the right way. Give them a high-nitrogen fertilizer from the start.

I sincerely hope this helps.

PAMELA J.

Where do you live? What is the weather like there now, and is that 'normal' for this time of year, or warmer or colder? The gardenia is a TROPICAL plant that doesn't do well as an outdoor plant in most of the U.S. I've seen some growing in the 'greener' parts of Southern California, and have heard they grow well in Georgia and Alabama, but that's about the ONLY places they do well. Your leaves are falling off, and your flowers are yellow and falling off because your bushes are either getting way too much water or not nearly enough water. They also need a good deal of 'shade' ... Gardenias don't do well in 'full sunlight' at all, and usually getting two hours of full sun is 'too much' if it's not 'morning sun.' Unfortunately, Gardenias also HATE being 'moved' ... and it's that moving that may be responsible for the plants doing 'well' at first then 'going bad' on you. If they die over the winter, buy some more plants, but keep them indoors as house plants, and once you put them in a spot (be sure it's a 'good spot' DO NOT MOVE THEM again! They'll thrive and bloom every OTHER year for at least ten years, and I've had one that lasted 20 ... but Gardenias are 'difficult to grow' even for most 'professional gardeners' ... try planting a Camellia with white flowers instead. They don't have much 'aroma' but they look nearly the same and are MUCH hardier as an outdoor plant.

Fertilizing Gardenias

FERTILIZING

Gardenias are sensitive to high salt levels in the soil which results from using hard water and fertilisers. To prevent salt buildups, do not over fertilize and periodically leach the soil with rain water to wash out excess salts. Gardenia plants require to be fed through spring, summer and autumn with Azalea & Camellia food.

GARDENIA PESTS & PROBLEMS

Yellow leaves

One of the most ask questions about Gardenias is the yellowing of older leaves in late winter and spring. This is usually a sign that the plant is moving its magnesium to the new growth. In the beginning of spring feed with Epsom Salts (Magnesium sulphate) will usually solve this problem.

To avoid getting other nutrients out of balance, only apply Epsom Salts no more than once a year.

Gardenia plants that are healthy will grow vigorously and are less likely to be affected by fungus problems. Planted in an ideal position, kept mulch and well fertilised regularly, will help most gardenias to stay robust. Always keep a close examination of the plants and deal with problems as soon as they materialize.

Use good soil. Treat the soil with fertilizer for gardinias. Unlike most plants, they need special soil with acid. Water well but the soild is the key. They need full sun to bloom well, otherwise you will have a nice green plant and no flowers.

Check that your soil is acidic. Gardenias simply cannot uptake nutrients from an alkaline soil. A good feed every three weeks with an acidic food will help them. They also yellow as they age.

If the leaves are yellow, they need iron chelate.

Actually gardenias are very hard to grow. We usually enjoy them one summer, throw them out, buy new ones the next summer.

Click this link:

http://www.uri.edu/ce/factsheets/prints/gardeniapt...

Probable too much watering -- I love gardinas-- mom and dad had a huge bush in back of the house and the fragrance was outstanding... We Lived in Toledo Ohio