Colorful invasive vine is 'Bittersweet'

I saw this vine growing in my trees when its leaves turned bright yellow. Now it has pretty orange berries but it's strangling my trees! I'm afraid its weight will pull them down in a blizzard. It's the very devil to remove — I hacked away with a machete, brush hook, and shears for an hour and just made a dent. What is this villain? Any environmentally friendly ways to remove it?

Pull it up and you'll see orange roots, too. The vine is Oriental Bittersweet Celastrus orbiculatus, an invasive non-native plant. Other than birds, it is sometimes spread by people who like to decorate with the vines in the fall. Obviously this should be avoided.


Pull young plants. Cut others' stems near the ground and within 5 minutes apply a systemic herbicide containing glyphosate or triclopyr to the cut surfaces. You can use a sponge or paint brush to target the chemical precisely.

After this kills the roots, you do not need to remove all the upper vine unless its weight threatens the tree. It will decompose in place. Cut stems without a chemical application will repeatedly try to grow again, but if you keep at it some day you would exhaust the roots.  Refer to our website's publication Invasive Plant Control in Maryland:

Two years ago I bought an orange tree. Since then it has grown but has not flowered or produced fruit. Is there anything I need to do to help?

Happy orange trees flower in summer, though the exact time can be variable. Orange trees like four hours or more of direct sunlight daily. Normal room temperatures are fine. Enhance humidity by placing the plant on a water-filled tray with pebbles in it. Do not allow the pot to actually sit in the water.

From spring to fall water moderately, allowing the top inch of soil to dry between waterings, and feed with a high-potash, "tomato-type" fertilizer every two weeks. The tree must have a rest period (usually in the winter) during which you water only enough to keep the soil from drying out and do not fertilize. To force flowering, keep it cool and dry for about a two-month period. Fruiting requires cross-pollination between blossoms, so if there are no insects to pollinate, you must do this over a few days with a soft brush.

University of Maryland Extension's Home and Garden Information Center offers free gardening and pest information. Call 800-342-2507 or send a question from the website at

Plant of the Week

Red Maple 'Red Rocket'

Acer rubrum 'Red Rocket'

Want a columnar shade tree that cools you in the summer, turns heads in the fall and fits in limited space? 'Red Rocket' red maple does it all.

Fast growing, yet with strong wood, all red maples are a top choice for native deciduous shade trees due to their sturdiness and tolerance of soil types, conditions, and being transplanted.

There are many desirable cultivars of red maples, so be careful to select the one with the growth characteristics that best suit your site.

Red maples can grow over 100 feet in height and width, whereas 'Red Rocket' is much shorter and narrower, closer to 35 feet tall and 8 feet wide.

—Ginny Williams