If you need to fast track some exotic flair for your garden or deck, hibiscus plants are your answer. Incredibly simple! Available in a wide range of vivid colours, their huge flowers will charm everyone. Choose the varieties and colours that will make your garden sing.
Hardy hibiscus plants
Perennial hibiscus 'Swamp-rose-mallow'(Hibiscus moscheutos) and the deciduous shrub 'Rose of Sharon'(Hibiscus syriacus) are hardy to our climate and can be planted directly into the garden. Plants can withstand winter temperatures of -30ºC! The slightly more delicate Rose of Sharon will, however, appreciate some protection from the wind.
Planting
Hibiscus plants really do thrive in full sun (6 to 8 hours), sheltered from the wind, and in rich, moist and slightly acidic soil. Since they flower in late spring and never before the end of May, plant your hibiscus behind early-flowering perennials in the flowerbed.
Steps
- Plant after all risk of frost has passed.
- Dig a hole twice as big as the plant is wide.
- Place the plant in the hole so that the crown is at ground level.
- Fill in the hole around the plant and water.
- Space plants 2 to 3 feet apart.
Watering and fertilizing
- Water regularly to maintain moist though well-drained soil.
- Add compost around the base of the plant in the spring.
- Throughout the summer, apply a balanced 10-4-12, 9-3-13 or 10-10-10 fertilizer. Do not use fertilizers with extra phosphorous.
What to watch out for and what it may signify
- Lower leaves are falling off: too little water.
- Buds don't open: too little water.
- Not many buds or flowers: too little sun.
- Check for Japanese beetles and treat if necessary.
Fall
- Cut plants back to 10 cm. Never cut back to ground level since roots may freeze.
- Add a generous layer of mulch.
Hibiscus are happiest - and flower more abundantly - in warm temperatures. Place them out of the wind and mulch around the plants.
Annual hibiscus plants
Chinese hibiscus (Hibiscus rosa-sinensis) is a tropical hibiscus shrub and in our northern climate, definitely an annual. Grow plants outside in containers during the summer. You may extend the life of your plants by bringing them indoors during the winter.
Summer
- Use 10 to 12-inch containers and quality potting soil.
- Place in full sun; plants require a minimum of 6 - 8 hours of sunlight per day.
- Ensure moist soil at all times.
- Fertilize with 10 - 10 - 10 or 12 - 6 - 8 fertilizers.
What to watch out for and what it may signify
- Yellow leaves: too little fertilizer, or the fertilizer contains too much phosphorous.
- Buds dropping off: plants require a stable location.
- Insects: spray with water and use an insecticidal soap.
Fall
- As soon as temperatures start to dip, bring your hibiscus indoors. Don't wait for the first frost!
- Leaves will change colour and drop, but that's normal; plants need to adapt to their new environment, then new leaves will appear.
- Let the soil dry out between waterings.
- Towards the middle of winter, repot your plant, prune and fertilize.
