Q&A: Snags, Money Tree and More
Master gardener Paul James answers gardening questions about mums, horsetail rush, snags, money tree and more.
Q. Are mums perennial?
A. It depends. Most mums — including the vast majority of store-bought mums— are hardy to USDA Zones 4 or 5. But there are a few that are hardy to Zone 2 and there are even a few that hardy only in Zone 10, which means they must be treated as annuals in most parts of the country.
Used in the gardens of China since before 550 BC, mums are extremely popular today. My guess is that at least 90 percent of those sold in the U.S. are planted in containers for fall color, although there are certainly a number of gardeners who plant mums directly into the ground. But those who grow mums as perennials are a pretty dedicated lot because the plants require a fair amount of maintenance. For example, the foliage must be pinched back several times throughout the growing season to maintain a bushy plant from early spring to mid-July, at which time the pinching comes to a halt so that flower buds can develop. Mums are also very shallow-rooted and in areas where hard frosts occur, they must be mulched heavily to prevent heaving or being pushed right out of the ground in winter.
Q. Have you ever grown horsetail rush?
A. Yes, but never directly in the ground because it can take over a landscape faster than you can say Equisetum, which just happens to be the plant's Latin name. In pots, however, whether planted in soil or grown in water alone, horsetail rush is a beautiful upright plant that can reach four feet in height. But just how did this plant get a botanical name and common name that refers to horses? Equisetum is poisonous to horses!
Q. I've heard snags are good for wildlife. How so?
A. A snag is nothing more than a dead tree. And as long as it doesn't pose a threat to people or nearby structures, it's good to let it be. Snags can provide a lot of great benefits to all sorts of wildlife. They're a rich source of food for birds, because a number of insects feed on the decaying wood, and they also provide nesting sites for birds and other critters.
Q. Does the expression "half day of sun" mean morning sun or afternoon sun?
A. There is no hard and fast answer because it depends on where you live. The angle and intensity of the sun varies depending on location. Generally speaking, a half day of morning sun is good for plants if you live in the southern half of the U.S. and either morning or afternoon sun is fine if you live in the northern half.
The real problem is that the afternoon sun in the South can literally cook plants--even those plants that are said to tolerate full sun. In fact, I've often said that the real key to successful gardening in the South--and much of the Midwest for that matter--is to give plants four to five hours of morning sun followed by afternoon shade. And, remember too, that a number of landscape plants--especially those grown in the North and shipped to nurseries in the South, like hydrangea and viburnum--may have labels that say they'll grow in full sun. While that may be true in the North, in the South they'll almost certainly require afternoon shade.
Q. How hard is it to overwinter cacti in the house?
A. It's quite simple actually, assuming that you can provide the plants with enough light. In fact, cacti make excellent low-maintenance houseplants, but during the winter months make sure you don't over-water them. In fact, water only when the leaves begin to shrivel, which may mean watering only every few weeks or months. And don't feed them at all since fertilizers can be fatal to indoor-grown cacti.
Perhaps the best way to answer your question is to show you a cactus that I've not only overwintered indoors but also grown indoors for the last three years. It's a Peruvian cactus that is so healthy I can't actually get it through the door.
Q. Can I overwinter an Alocasia indoors?
A. Yes, these tropical beauties are ideally suited for the indoor environment and their colorful and variegated foliage is a refreshing break from the usual green. Alocasias prefer low-light conditions and temperatures around 70 degrees F even at night. Fortunately, these are conditions typically found in homes during the winter. Alocasias do, however, require frequent misting to maintain humidity; otherwise you'll begin to notice some ugly brown spots along the leaf margins. These plants also require more water than most houseplants do, especially during the winter months, so try to keep the soil moist but never soggy.
Q. Have you ever grown a money tree?
A. Although the expression "money doesn't grow on trees" is at least as old as I am, the money tree is much older. And according to feng shui masters, the money tree symbolizes wealth and prosperity. The money tree's five leaves are said to represent the five feng shui elements—metal, wood, water, fire and earth. This curious and attractive houseplant requires moist soil, medium to bright light—such as that offered by a south-facing window—but little, if any fertilizer. In other words, it's easy to grow, and perhaps best of all, you can pick up a money tree for a few dollars, which means it will give you a whole lot of bang for your buck!