Gardenia (cape jasmine), is one of the most beautiful flowers that can grow in the yard, but caring for it is a little difficult. Gardenias require a certain soil acidity, plenty of water and light, cool temperatures and high humidity. This plant is also very susceptible to pests. However, after overcoming this challenge, you will be greeted with beautiful and fragrant flowers, from spring to summer.
Step
Part 1 of 3: Outdoor Planting
Step 1. Find a sunny area for gardenia light shade
Unlike most plants, gardenias are sensitive and picky about the environment.
- Gardenias thrive in bright light, high humidity, and a balanced supply of moisture and nutrients.
- Although it can be grown indoors, heat, dry air and winter can make gardenias spiral downward.
- The ideal season for growing gardenias is during the spring or fall, when the sun's rays are not too hot.
- Flower buds will fail to form if the day temperature is higher than 21 degrees Celsius, if the night temperature exceeds 18 degrees Celsius or below 15 degrees Celsius at night.
Step 2. Test the pH level of the soil to determine if gardenias thrive best when planted
pH is a measurement to determine the acid content of the soil. Acidity that is too high will not be suitable for gardenia roots.
- Acidity is measured on a scale of 0-14, 0 being the most acidic and 14 being the most basic. Gardenias prefer acidic soils, so a pH level of 5 or 6 will be optimal because the acid level is moderate.
- If necessary, add sulfur & white powder which can be purchased at most plant or home improvement stores & to help lower pH levels higher than 6.
- The soil should be rich and well drained. Gardenias need a lot of nutrients, but roots can die if there is too much water in the soil.
Step 3. Dig a hole in the ground about the size of a gardenia root ball
Make sure the hole is 2-3 times wider, as you will be backfilling it with soil once the root ball is planted.
- The root ball is the mass formed by the roots of a plant and the soil around it.
- If the soil is in poor condition, add a little compost to the hole before placing the root ball. Compost is an organic fertilizer and will add nutrients to soil that may be deficient.
- Carefully choose a place to plant the bush. Planting plants close to the house will give the scent of blooms from where the plants are or from a window. But being too close to home also means the pH of the soil becomes too high for plants to thrive.
- Also keep in mind that gardenias need a lot of light, but cannot tolerate heat. Plant plants near the bedroom window rather than the kitchen window.
Step 4. Arrange the gardenia root ball in the hole
Fill the hole half full with soil and water it.
- Doing this will help to settle the soil and remove any air pockets. You want the gardenia roots to fit snugly into the soil so it can absorb lots of water and nutrients.
- To plant a lot of gardenias, make sure you leave a distance of 0.9-1.8 meters between each root ball. Gardenias can grow anywhere from 0.6 to 2.4 meters in height or width. Planting too close can cause overcrowding or competition between root water and nutrients.
Step 5. Fill the remaining hole with soil after the water has drained
Gently pile the plant around the root ball so that it is slightly loose. Thoroughly flush.
Part 2 of 3: Outdoor Care
Step 1. Water the gardenias with 2.5 cm of water once a week
Gardenias usually need 2.5 cm of water to thrive, so adhere to this standard at every watering.
Monitor humidity levels frequently, and water thoroughly as the above-ground water dries up. Avoid over-watering the soil, as roots that are too wet will be difficult to breathe
Step 2. Apply a 5-10 cm layer of organic mulch to the gardenias
Mulch is made from decaying organic matter, such as leaves, bark, or compost, and can be purchased at plant stores.
- Mulch not only enriches the soil, it also keeps the soil moist, reduces weed growth, and maintains a constant soil temperature.
- For best results, choose a mulch made from wood chips, sawdust, or ground bark.
- It is very important to apply mulch, as gardenia roots are shallow and therefore very susceptible to weeds.
Step 3. Apply an acidic fertilizer to the garden every 3-4 weeks
Regular fertilization will increase the growth of healthy gardenia flowers.
- Make sure you apply acid fertilizer. The nutrients in this special fertilizer are formulated for plants that prefer acidic soils. Applying regular fertilizer may not be able to sustain gardenias.
- Do not fertilize too much, because the salt will accumulate salt so that it can damage the plant.
Step 4. Spray gardenias daily with a spray bottle
In addition to providing adequate sunlight, soil, and water, provide moisture for plants.
- Spraying with water will provide moisture around the plant, but only temporarily. Therefore, do it every day to make sure the gardenias are alive.
- In addition to spraying, gardenia can be planted in groups but not too dense. Planting in groups will create pockets of moisture. To increase the humidity even more, you can place a dish of water in the center of the cluster. When the water evaporates it will cover the surrounding gardenias.
Step 5. Prune gardenias in early spring to form a bush
Pruning after flowering will encourage the plant to flower more.
- Pruning young, dormant gardenias will cause the plant to bloom more. Young plants are very hardy and easy to repair stems that are cut because they are not yet actively growing.
- Remove bony branches and faded flowers. Gardenias are woody shrubs, so remove older woody stems to encourage new branch growth.
- Prune the lowest branch that is almost touching the ground. This is dangerous because it can cause infection.
- Do not prune all the leaves. Leave some leaves so the plant can still produce food for the root system.
Step 6. Watch out for whiteflies and mealybugs
These insects are very attracted to gardenias and can interfere with growth or cause the plant to die.
- The mealybug is a gray, segmented pest. These ticks feed on gardenia sap and leave a waxy coating on the plant. This can cause twigs to die, interfere with plant growth, and cause early leaf fall.
- Whiteflies are small white insects that resemble small gnats. This insect produces a kind of honey and black sooty mold that grows on it. This fungus can cause gardenia leaves to turn yellow and fall prematurely.
Step 7. Coat the gardenia with insecticidal soap or horticultural oil in case it is attacked by pests
This solution will kill mealybugs and whiteflies, and can be purchased at most local plant stores.
If large mealybugs attack, cover the gardenias with a good dose of insecticidal soap or horticultural oil. Two days after applying the first insecticidal soap, cover the soil with a fungus called Beauveria bassiana which is useful for killing mealybugs that eat roots. Beauveria bassiana is also available at most home improvement/plant stores
Step 8. Cover the gardenias with a blanket or cardboard box during the winter
Since gardenias are very sensitive to cold, they need adequate insulation and protection from harsh winter winds.
- Secure a cardboard box large enough to cover the bush without bending the branches. Use an old blanket, straw, or bubble wrap to protect the plant while in the cardboard box.
- However, damage from frost or cold can cause the tips of the branches to die and turn black. When this happens, trim the branch a few inches below the damaged area with sharp pruning shears.
- Or, you can put gardenias in pots and keep them indoors during the winter. While plants are at a higher risk for aphids, there are steps you can take to make gardenias better indoors.
Part 3 of 3: Indoor Planting
Step 1. Place the gardenias in an area that receives half a day of direct sunlight
For example near a window facing south.
- It will be difficult for you to keep gardenias indoors during winter when sunlight is rare. You can add light by turning on plant lights.
- Gardenias should be in a room with a temperature of 12.7 degrees Celsius during the day and 17.7 degrees Celsius at night. Adjust the thermostat in your home and monitor the growth of the gardenias.
- Keep plants away from litter and do not place gardenias in places where they can receive direct heat from the stove. Its hot drying properties can cause gardenias to crumble.
Step 2. Water the gardenias once per week and fertilize once in the spring and once again in the summer
Use an acidic fertilizer to promote healthy growth.
- Water the gardenias as needed. If the top of the soil is dry to the touch, water it until the soil is moderately moist.
- Check the soil pH frequently to make sure it stays in the 5 and 6 range. Use food crops specifically designed for flowering plants that prefer acidic soils. A formulation for azaleas will work well.
Step 3. Use a humidifier to increase the humidity in the room
This is especially important in winter.
- As previously stated, you can group potted gardenias into a cluster around a dish of water to increase humidity. Be careful when spraying plants, as using direct water and humidifiers can cause mold growth on gardenias.
- You can also place gardenia roots directly into the gravel and water tray. First, put a layer of gravel on the tray and add water until the gravel is not covered enough. The gravel will hold the plant above the water so the roots don't become submerged. When the water evaporates, the humidity in the air around the plant will increase.
Step 4. Prune gardenias in the spring to keep the plant sized
This will also encourage the flowers to bloom properly.
The best pruning time is after the flowers have fallen. Cut the dead wood until the plant reaches the size you want
Step 5. Check for ticks frequently
Indoor gardenias will attract many other fleas besides mealybugs and whiteflies.
- Among the ticks to watch out for are aphids, tiny pear-shaped insects with long legs and antennae. These lice can be expelled with a solution of one part liquid soap and one part water. Spray the tops and bottoms of the leaves. This treatment is also effective on mealybugs.
- Spider mites are small and difficult to see with the naked eye. To monitor for spider mites, gently pat gardenias on a piece of white paper. If you see red, yellow, brown, or green dots, it may be spider mites. Repel these pests with Mambu Oil, a vegetable oil that comes from the Mambu tree. This oil is available at most grocery or supermarket stores.
- Bamboo oil will also repel all these pests. If gardenia leaves turn yellow during this treatment, nematode root lice may attack. Root nematodes are microscopic parasitic worms that attack plants at the roots. Unfortunately, there is no treatment for this type of pest.
