Garden Q&A: Goldenrod not ragweed and managing saplings
By Ellen Nibali
Oct 15, 2020 at 8:00 AM
Why do people insist on growing ragweed with otherwise beautiful fall flowers? Saw these at a conservancy. A sign said they were native but, really, ragweed? I have allergies.
It’s a persistent misconception that the yellow sprays of goldenrod are ragweed, the hay fever culprit. They are not.
Seen growing wild this time of year, goldenrod species range from shy shade lovers to rampant sun lovers. “Fireworks” is a good medium height cultivar for home gardens, but it’s worth searching for more garden-worthy goldenrod species.
The other flowers in your naturally color-coordinated bouquet are native black-eyed Susans and purple obedient plant or false dragonhead (Physostegia virginiana). Goldenrod and obedient plant spread by runners to form a bold patch. All are deer resistant or deer-proof.
The dreaded ragweed is native, actually, but has lacey leaves and “meh” greenish flowers. Easy to pull.
A sapling quickly grew two feet tall up against our foundation. We think it’s a tulip tree. We’re afraid the roots will harm the foundation, but my spouse cut it down and didn’t pull up the roots. Won’t it just grow back? He says if he keeps cutting it, the roots won’t spread. Is this true?
Ultimately, it’s often less work to pull or dig out seedlings when soil is moist and be done with it. When cut, a small diameter sapling may or may not have enough stored root energy to resprout. Yes, continually cutting new growth will exhaust the root system, but only provided new leaves aren’t left on long enough to renew the root system. This can go on annoyingly for years.
Happily for you, tulip poplars are not notorious resprouters. However, don’t try that with tree of heaven! Cutting it stimulates a forest of new suckers. This is important to know now, since the invasive insect known as spotted lanternfly has gotten a foothold in Maryland, and tree of heaven (Ailanthus) is a favorite food and attractant for them.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Maryland’s Gardening Experts” to send questions and photos.