Mystery flower can be grown outdoors

A: The flowers in the photo are a large-flowered florist strain of Canterbury bells. You're right; they do look like huge lily-of-the-valley blossoms. Canterbury bells can also be grown in our region's flowerbeds. They're considered a biennial, forming a green plant the first year from seed, then flowering the second year. They easily seed themselves once they begin blooming, so a patch of Canterbury bells usually blooms every year with the presence of both first-year seedlings and second year flowering plants.

Q: I brought a Dracaena marginata houseplant with me from Michigan in 2004, when it was about five feet tall and a single stalk. Now one shoot is over 14 feet tall. How tall will this plant get and what's the best way to propagate and prune this plant? I'm concerned about it hitting the ceiling. - Greg Morgan, Ponsford, Minn.

A: Dracaena marginata has several common names including dragon tree, or simply dracaena, or red-margined dracaena. In its tropical native habitat, it grows as a small tree, or shrubby tree, so indoors it eventually becomes tree-like, as it's done for you. The height can easily reach 20 feet or more if light is optimal.

The height of dracaenas can be limited or maintained by pruning the growing tips. If a plant has become very tall, with all foliage growing on the tips of bare trunks, cutting the plant back drastically can stimulate new shoots from the lower stems.

Before performing a drastic cutback, the top, bushy parts can be propagated by air-layering, which involves wounding the stem, wrapping it with sphagnum moss enclosed in plastic, then cutting this 'new' plant from the mother plant, once it's rooted. The mother plant can then be cut way down, and hopefully branches will sprout from it's lower trunks.

Q: I'm writing in response to your column about Epsom salts and tomatoes. I've used them, not in treating blossom end rot, but to affect the tomatoes' flavor. Last year, I forgot and there was definitely a difference. Also, I place crushed egg shells in the soil surrounding the tomato plants to supplement calcium. I have not had a problem since I started doing this. - Dorothy Broste, Bemidji, Minn.

A: I hadn't heard of Epsom salts effect on flavor. Previously I quoted North Dakota State University's view on Epsom salts: "Blossom end rot is caused by a deficiency of calcium. Epsom salts contain magnesium sulfate - no calcium at all. Adding Epsom salts to the soil may create more rot since magnesium and calcium ions compete for uptake into the plant."

Most of our soils have sufficient calcium, but it's the tomatoes inability to absorb the element that creates a problem. My mother always added eggshells to plants, just as you're doing. The sharpness of crushed eggshells on the soil surface helps deter slugs, also.

If you have a gardening or lawn care question, email Don Kinzler at ForumGrowingTogether@hotmail.com. All questions will be answered, and those with broad appeal may be published, so please include your name, city and state for appropriate advice.