Eliminating Rose of Sharon Seedlings – A Complete Guide

The rose of Sharon is a popular flowering shrub grown for its abundant blooms that appear in late summer. But one downside of this plant is that it readily self-seeds, resulting in sometimes hundreds of volunteer seedlings emerging all around the garden. As fast growing and adaptable plants, these rose of Sharon seedlings can quickly get out of control.

In this comprehensive guide, we will explore the reasons for the rampant spread of rose of Sharon as well as detail various methods for effectively eliminating these unwanted seedlings.

Why Rose of Sharon Spreads Aggressively

There are two key reasons why rose of Sharon or shrub althea (Hibiscus syriacus) tends to spread invasively via self-seeding:

• Prolific blooming – Few flowering shrubs can match the sheer number of blossoms produced by rose of Sharon from early summer into fall. More flowers mean more seeds.

• Efficient seed dispersal – The small seed pods that form below each bloom split open when ripe, allowing seeds to drop near the parent plant. Winds and rain also spread seeds further afield.

Once on the ground, rose of Sharon seeds germinate readily to produce fast-growing seedlings. Within a season or two, they can reach over 6 feet tall Left unchecked, rose of Sharon will form large thickets or colonies

While some may appreciate self-seeding shrubs for their low maintenance, most gardeners view the seedlings as weeds. Fortunately, there are effective control methods.

Hand Pulling and Digging

Manually uprooting seedlings is labor-intensive but avoids herbicide use. Small seedlings can be hand pulled, while larger ones will need digging out with a trowel or shovel.

Tips for manual removal

• Wear gloves to protect your hands from thorns on stems.

• Use a garden fork to loosen soil if seedlings don’t pull out easily.

• Shake or rinse all soil off roots to prevent regrowth.

• Focus on seedlings growing in lawns or garden beds. Remove those in natural areas only if invasive.

Hand pulling is easiest when soil is damp but not soggy. Use a weeding tool for leverage on stubborn seedlings. Removing them as soon as they appear in spring is best.

Smothering Seedlings

Covering areas where seedlings are growing deprives them of light and smothers them within a month. Options include:

• Tarps or plastic sheeting
• Cardboard or layered newspaper (wetting paper speeds the process)
• Natural materials like wood chips, mulch, or pine needles

You can even solarize areas by moistening soil then covering with clear plastic for several hot weeks. Just be sure to remove desired plants first.

Applying Pre-Emergent Herbicide

Pre-emergent herbicides like Preen prevent seeds from sprouting but don’t kill growing plants. Use around established rose of Sharons to stop seedlings from emerging.

Key tips for pre-emergents:

• Apply in spring before seeds germinate. Time a late summer application for any new seeds.

• Reapply after heavy rains which can wash away products.

• Avoid spraying near wanted plants—herbicide will prevent those seeds from sprouting too.

• Read and follow all label directions carefully to avoid lawn or plant damage.

While pre-emergents offer effective control, hand pulling may be a better choice for gardens with frequent seed starting.

Using Post-Emergent Herbicide

Non-selective, post-emergent brush killers will destroy any existing woody seedlings. Glyphosate products like Roundup are effective. Other options include triclopyr and 2,4-D.

How to safely use post-emergent herbicides:

• Spot treat individual seedlings rather than broad spraying, which can harm other plants.

• Apply carefully to leaves with a paint brush or targeted sprayer to avoid drift.

• Never use near desired trees or shrubs—these products kill any plant they contact.

• Follow all label precautions to avoid environmental or personal harm.

Repeated hand pulling is labor intensive but eliminates the need for herbicides in home gardens. Consider removal options first.

Prevention Is Ideal

Stopping seeds from forming in the first place is the best approach. Here are two simple preventive methods:

• Grow sterile cultivars like the Chiffon series that don’t produce seeds.

• Deadhead spent blooms and developing seed pods before they mature seeds.

Vigilant deadheading through the season will halt self-seeding. But existing seedlings also need removal using techniques above.

Be Persistent and Patient

Eliminating unwanted rose of Sharon seedlings requires dedication over time. Hand pull emerging seedlings each spring before they get large. Herbicides provide chemical control but should be used judiciously. Combined with prevention measures, your effort will pay off in stopping the spread.

While rose of Sharon can be invasive, totally banning a beloved flowering shrub is not always necessary. Instead, control self-seeding around your property and in natural areas where it could crowd out native plants. With smart integrated management, you can still enjoy the beauty of rose of Sharon blooms without the nuisance of its progeny.