Q: The medicinal plant comfrey is taking over our septic field. Are these good for something?
Virve Martinoff,
Langley
A: Comfrey is a nutritious accelerant that helps compost decompose quickly. A cream made from the leaves has also been used as a healing gel for external use only. This is sometimes sold in natural health stores.
In past centuries, the young leaves were eaten in spring by country people and sometimes used as medicine for stomach ailments. This isn't done now because in recent years studies found it could cause liver damage.
However, certain comfrey species are reputed to be useful as animal fodder, though my personal feeling is caution should prevail here, too.
It's important to remove and garbage all seed heads before composting the comfrey. It's horribly invasive and the roots are tenacious, too, so you may have several years of mowing on your septic field to get rid of all the new shoots.
Q: I live in a condo that has a spot under cover by the door, which is not dark but never gets direct sunlight. Most flowers, such as impatiens, seem to fade and wither. I planted coleus there in a large deep pot and they seemed to thrive. Then half died. I uprooted them, changed the earth and added new ones. Some are dying again. I don't believe I have over-watered.
Marlene Wilson,
Vancouver
Q: It's more likely you've under-watered. Containers dry out fast and the situation under cover means they don't get any water aside from what you give them. Also, heat from the house wall and ambient temperatures in summer have a drying effect.
I wonder what potting mix you used when you changed the soil. Most commercial mixes are peaty and once peat dries out it's almost impossible to re-wet. If your container dried out completely, even once, it could create a chronic drought problem.
When pots dry out, the soil tends to pull away from the inside of the pot. Much of the watering may then fail to penetrate the plant roots because it's flowing down the inside of the pot and out of the drainage holes.
Next time it would help to add commercial compost or sea soil to the potting mix.
I've seen hostas, epimediums and ferns growing in difficult shady situations under roof overhangs and decks. The easiest-to-get epimediums grow about 30 centimetres and have yellow or occasionally white flowers in spring. The leaves die in fall but remain until early spring when gardeners usually cut them away. If you don't cut them away, the flowers peek through the dead leaves and before long, the new, green leaves overflow the old ones.
With epimediums, you want a vertical element-perhaps tall, curly branches from a florist. I've seen effective contorted willow branches spray-painted white for a shady door-side container.
