How to deal with a weed vine
Still thoroughly enjoying your column. The problem is a “weed, vine,” growing in a patch of iris. These have been here decades and we pulled them, but they have come back with a vengeance. Is there anything we can do to get rid of them without destroying the iris bulbs? Keep up the good and informative articles. Stay healthy and safe.
— Judith Hausman
Judith sent a picture
and I believe what she has is Bishop’s weed (Aegopodium podagraria, aka ground elder or goutweed). It is an intruder, from Europe, Northern Asia and Siberia. Brought in as an ornamental, it is resistant to deer, insects and disease, spreading quickly as a ground cover.
Bishop’s weed escaped cultivation and has been spreading from Rhode Island since about 1863. While easy to grow and attractive, it is considered invasive in Pennsylvania.
Within the iris bed, your only alternative is persistent hand pulling and lots of patience.
Hibiscus with yellow leaves
I would like to thank you for your column which always has such helpful tidbits. I am hoping you can answer a question I have about my potted hibiscus. It has done well with many flowers until last week. Suddenly, all the leaves are turning yellow. I had fertilized with a seaweed product and wonder if this was too much for the plant. I have continued leaf growth but no blossoms. I trimmed it several inches hoping to
restore its flowering on new wood. So far that has not happened. I am so impatient for it to recover that I plan to use a blossom booster fertilizer this week.
Last year I had a beautiful healthy full and many blossomed hibiscus in the same location so I think there is plenty of sun. I do allow the soil on the top 2 inches to dry out between waterings.
Thank you for whatever help you may provide, even commiseration.
— Ellen Legg
Fran and I have also grown
potted hibiscus plants. One lasted over 10 years, sometimes almost leafless, sometimes yellow, but mostly full, leafy and covered with beautiful flowers.
Since Ellen is growing
hers in a pot, I’m guessing we are talking about a tropical hibiscus, also called a Chinese hibiscus. They have some specific needs:
Six to eight hours of sunlight.
A well-draining potting mix, preferably with compost (to retain moisture) and perlite or vermiculite (to lighten soil and improve drainage). A soilless potting mix is best.
The container should be only an inch or two larger than the root ball; these plants perform best when the roots are slightly crowded. Make sure there are adequate drainage holes and use a saucer to collect and get rid of excess water.
Water when the top inch of soil is still slightly damp. Water until excess flows
through the pot. Plants may need frequent watering in hot weather or dry, sunny locations. Always empty drainage saucers after watering.
Do not allow to get cold. Although hibiscus will tolerate short exposures to cool temperatures, they do not do well below 45°F., so they must be brought indoors in our temperature zones (5-6).
So what makes leaves turn yellow? Many things:
Too much water or poor drainage will affect the roots — root rot.
Too little water, particularly in hot weather.
Too cold — move indoors; too hot — locate in a place with afternoon shade and keep watered.
Nutrient deficiency — add a micronutrient supplement or fertilize with a weak water-soluble fertilizer or use a slow-release fertilizer.
Too much phosphorus, don’t use a bloom booster formulation or any fertilizer with a high middle number formulation.
Too much sun (burned leaves and white spots); too little sun, pale leaves. Relocate to adjust light.
Ready to go dormant. Cut back on watering, move to a cool, dark place and water only enough to keep soil barely moist until you are ready to return to light in spring.
Insect damage: spider mites, aphids, thrips, scale and whitefly. Treat according to the container instructions with a mild insecticidal soap.
What else should you know:
Root pruning is an option if you want to keep the plant in the same pot but it needs more room. Do not remove more than a third of the roots.
You can prune to remove damage, shape plant, control size, reduce watering needs and encourage branching.
When repotting, allow the plant to rest in light shade for about two weeks after transplanting.
I would recommend more careful watering with attention to removing collecting water in saucers. If you are fertilizing, cut back or find a mixture for hibiscus (9-3-13, 2-4-18, or similar values). Check for pests and examine the roots for rot.
We have had some luck with micronutrient solutions like Ironite or Sprayn-Grow. We are currently testing one on Jack’s tomato patch. So far treated plants are outgrowing and out flowering untreated ones but it is still early.
A reader’s tip for growing ferns
Last week there was a question about ferns in baskets. This is one reader’s solution to watering without a mess:
I’ve had great success over many years in having my ferns thrive outside hanging on my shady front porch. I place the ferns in their original pots in a decorative basket containing a plastic liner. They don’t seem to mind occasional wet feet and the water remains in the pot rather than flowing on the ground if the soil has dried out.
— Sharon Lowe