Plant these shrubs in the spring or early fall about two to three feet apart for adequate room. ‘Blue Chiffon’ is sterile and will not self-seed. It grows at a medium rate of about one to two feet per year. Deer are not likely to severely damage this plant but pollinators love it. Mulch the shrubs for weed control and to maintain soil moisture. The bushes are fairly tolerant of dry conditions once established. In fact, yellowing leaves can be an indication of too much water rather than too little.
Light
Grow these shrubs in full sun. Plant the shrubs where they will receive a minimum of six to eight hours of direct sunlight every day. In warmer climates, rose of Sharon prefers morning sun with protection from harsh afternoon rays, but they will likely tolerate a bit of overheating.
Soil
Rose of Sharon prefers well-drained, loamy soil enriched with humus. However it tolerates many types of less-than-perfect soil and polluted surroundings, which makes it a good plant for urban gardens. After planting, add a layer of mulch or finished compost to help keep the soil moist.
Water
This shrub requires consistent weekly watering until it is well-established. Water deeply to soak roots but don’t water again until soil surface is dry. this shrub dislikes extremes and won’t grow well in soil that is constantly wet or constantly dry. Mature plants are drought tolerant.
Temperature and Humidity
Though rose of Sharon is related to the tropical hibiscus, it tolerates a wider range of temperatures and humidity than its tropical cousins. It handles southern heat and northern cold better than other outdoor tropical plants. Rose of Sharon can grow in cooler zones than the typical hibiscus plant, which makes this an attractive shrub for gardeners in colder regions, as cold as USDA hardiness zone 5. This shrub is known to tolerate temperatures below zero Fahrenheit. It is tolerant of just about any humidity level, as well.
Fertilizer
Rose of Sharon is not picky about fertilizing. But don’t overfertilize the plant or it will produce lush foliage at the expense of blooms. When first planting , use a general-purpose, controlled-release fertilizer. Mix it into the soil from the planting hole. Give shrubs a meal of liquid fertilizer in late spring to early summer to boost their blooms. Don’t fertilize too late in the summer or you will encourage new growth which can be damaged by frost.
Pruning
Because it blooms on new wood (this year’s new stem growth), prune the rose of Sharon in late winter or early spring before new growth emerges. Pruning often is not necessary, although you might choose to prune for shaping, to maintain a specific size, remove dead or damaged branches, or to rejuvenate older shrubs. You can train your rose of Sharon shrub into a small tree but it will take a few years to fully accomplish the look. To do this, remove weak stems and branches halfway up the shrub. Then, trim the upper branches to shape the canopy into a tree. Do not trim or prune more than a third of the upper branches or canopy when shaping your shrub. Continue this method of shaping year to year.
Propagating ‘Blue Chiffon’ Rose of Sharon
Rose of Sharon is easily propagated by taking stem cuttings, but gather more cuttings than you think you need because not all will successfully develop into viable plants. Seeds might not result in plants that look like the parent, so if you want a duplicate of the parent rose of Sharon plant, it’s best to propagate with stem cuttings. Take cuttings in June or July as it begins to generate new growth long before the first fall frost. Here’s how:
How to Propagate ‘Blue Chiffon’ Rose of Sharon From Seed
You once could harvest an endless supply of seeds from rose of Sharon shrubs. The shrubs would self-seed readily and unwanted new plants would spring up quite readily. Breeders of ‘Blue Chiffon’ have solved the self-seeding problem: it is sterile and does not produce viable seeds. So, if you want to propagate ‘Blue Chiffon’ from seed, you’ll have to purchase the seeds and plant them in late spring so that the plants grow strong enough to survive the first fall frost.
Planting seeds outdoors
Planting seeds indoors
Potting and Repotting ‘Blue Chiffon’ Rose of Sharon
Though rose of Sharon is more typically grown outdoors in the ground, it can look lovely as a potted plant on the patio with other smaller container plants. This shrub, however, will grow large and heavy and can be a chore to repot. You will need to repot if the roots are growing out of the drainage holes of its existing container or it is getting top-heavy compared to the pot. It’s best to repot when the plant is dormant in the winter months (November through March).
Overwintering
In the northern end of its hardiness range, you’ll likely need to overwinter potted rose of Sharon plants. However, after the growing season, the shrubs might have become quite large. If you can’t move the pots and you live in a cold northern region of the United States, wrap the plants and containers to insulate them and move them to a sheltered location out of harsh winter winds. In warmer southern regions, there’s no need to prepare rose of Sharon for overwintering. For rose of Sharon plants growing outdoors in garden beds in in the northern range of its hardiness zone, you can protect the root zone with a layer of mulch or straw. If you are in a colder climate with outdoor shrubs, protect the plants’ crowns from cold and wind with a plant wrap.
Common Pests & Plant Diseases
Aphids and Japanese beetles commonly attack these plants. To control these pests, spray with neem oil for aphids and remove Japanese beetles manually and drop them into a bucket of soapy water. These plants are susceptible to leaf spot and canker, both of which can treated by removing infected parts before the disease spreads (if you spot the problem soon enough).
