Caring for Gardenias
Gardenias are a very popular flowering plant for many gardeners. Their popularity is due to the beautiful blooms and scent that these blooms produce. Unfortunately, these plants can be very difficult to care for. So many things can go wrong, and after one plant fails, a gardener may give up on raising them all together. However, there are simple ways to deal with the problems that crop up in caring for these plants. So if you are a gardener that wants to try raising these plants, or you want to give these plants another try, here are some tips for treating the most common gardenia problems.
Gardenia PestsClick thumbnail to view full-size
One of the biggest problems for gardenias are the pests that plague them. The major pests include:
- Aphids - One of the most common pests in the garden on all types of plants. These can be treated by spraying plants with a soap solution (one tsp of liquid soap to one gallon of water). Don't forget to spray on the underside of the leaves as well.
- Mealy Bugs - These can be treated by sprayin the plant with a soap solution or using a fine horticultural oil sprayed on the tops and underside of the leaves and plant.
- Scale - Can be treated with horticultural oil.
- Root Nematodes - There is no cure for plants infected with nematodes. If your plants have wilted yellow leaves and don't respond to the suggested treatments for yellowing leaves, your plant may be suffering from nematodes.
- Spider Mites - Can be identified by shaking leaves onto a white sheet of paper, then folding the paper in half and pressing the sides together. When you open the paper back up, check for red smeared spots. These spots are spider mites. They can be treated with Neem.
- Whiteflies - These small white flies collect on the underside of the plants leaves. Removed infected leaves and any plants that are infested. Treat the plants with Neem.
Yellow Leaves on Gardenias
Next to common garden pests, yellow leaves are the second biggest ailment of gardenia plants. There are three things that will cause yellow leaves on your plants.
- Cold temperatures. Gardenia plants don't like being outdoors in temperatures below 60 degrees Fahrenheit. If you live in a climate where temperatures dip in the evening or at other times of the year, consider keeping your plants in pots that can be moved indoors.
- Drainage problems. Gardenias hate having "wet feet." If their soil isn't well drained their leaves will turn yellow rather quickly. To remedy this problem in potted plants, place the pots up on marbles so the pot base is never sitting in water. Plants in the ground may need to be moved when they are dormant.
- Soil problems. Add a soil acidifier. Use azalea fertilizer, blueberry fertilizer, or MirAcid. Outdoor plants can benefit from pine bark mulch.
Gardenia Bloom Problems
1. Blooms won't open - Nothing is more frustrating to a gardener than when spring arrives and the gardenia blooms are hard and won't open. This problem can be solved by doing the following:
- Check the soil pH - It should be between 5.0 and 6.0. Adjust the soil if necessary.
- Proper drainage - Make sure your plant doesn't have "wet feet."
- Temperature - These plants need warm temperatures to bloom. Bring you plants indoors if they are in pots when the temperatures dip below 60.
2. Bloom drop - Usually happens when a plant is moved right before or when the plant is blooming. Plants should only be transplanted after they have bloomed for the season.
3. No blooms - Happens when you prune a plant too late in the year. The best time to prune the plant is right after the blooms die for the season. Be sure to to know what type of gardenia you have before you prune - some varieties bloom twice in a season.
Brown leaves or brown spots on leaves are usually caused by the following:
- Water splashed on the leaves when watering the plant
- pH of the soil is wrong
- Pests on the plant
- Not enough sunlight - these plants need 6 to 8 hours of full sunlight each day
- Not enough humidity - this usually occurs with house plants
- Poor drainage - check to see if your plant has "wet feet"
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.