Weather Forecast


Ask the Master Gardener: The right and wrong ways to water orchids

Orchids should be watered weekly, but don't use too hot or too cold water. Photo by Jennifer Knutson

Dear Master Gardener: I purchased an orchid and the directions say to water it with an ice cube each week. Since it's a tropical plant I wouldn't think putting ice on it would be a good way to water it. How should I water my orchid?

Answer: Most house plants originate in the tropics or subtropics and can be injured by icy water. Use room temperature water for all your houseplants. Never use cold or hot water to water your orchids. Orchid cells close when cold, therefore the roots do not efficiently absorb cold water. Hot water damages them. As a general rule, an orchid in a 6-inch plastic pot is watered weekly. However, if it is hot and dry in your house and the orchid is completely drying out in a few days or if you have it in a humid spot and the orchid stays damp for more than a week after watering it, then you need to pick up the pot to check whether it actually needs to be watered. Water drainage is crucial for an orchid, so it doesn't get overwatered. It can be tricky to tell if an orchid has been over or under-watered as the symptoms can look similar. If an orchid is under watered the roots will dry and collapse, leading to shriveled buds and leaves that turn brown and drop. When an orchid is overwatered, the root system can rot and collapse and the buds will also shrivel and the leaves drop. In either case, you should change the watering schedule.

Many orchids come double-potted, so remove the inner pot to give your orchid a good watering. Take it to a sink, make sure the water is at room temperature, and water the plant thoroughly, allowing the water to drain out for a few minutes. Make sure no water has collected on the leaves or in the crown, where the new leaves are emerging because this can rot new growth or create black rot spots on the leaves. Tilt your orchid on its side and allow the water to drain out or blow into the crown to drive the water out. If there is still water on the orchid, wipe it off with a soft cotton cloth. Orchids prefer a humid environment. To increase the humidity around your orchid, place a pebble tray with water in it under the pot, but make sure the pot is not sitting in water.

Dear Master Gardener: I keep hearing that I should mulch in the fall. Why should I mulch, what should I mulch, and what should I mulch with?

Answer: The purpose of mulching is to insulate soil so that it freezes gradually in the fall and thaws slowly in the spring. This reduces the heaving of plant crowns caused by freeze-thaw cycles. It also reduces soil moisture loss in dry autumns and open winters. Mulch is best applied after there is frost in the ground and removed in spring when temperatures have warmed and new growth becomes evident. Perennials, particularly tender perennials, are the primary beneficiaries of winter mulching. Tender shrubs can benefit, too, but mulch can also provide winter homes for voles and mice, who then grow fat on shrub bark. Usually 2-4 inches of mulch are recommended. Unlike some summer mulches, which are used to look pretty and can be costly, most winter mulches are free. Common ones are pine needles, straw, evergreen boughs (easy to remove in the spring), and shredded leaves. Unshredded leaves, particularly oak and maple tend to mat and mold. An often-unheralded benefit of mulch is that you can walk on it in the garden without getting your shoes muddy.

Dear Master Gardener: I still haven't planted my tulip bulbs. Since it is probably too late to plant them in the ground I was wondering how to force them to bloom inside.

Answer: Of all the spring-blooming bulbs to plant in the fall, tulips can be planted the latest. According to North Dakota State University Extension tulips can be planted up until the ground freezes, so go ahead and plant your tulip bulbs if you prefer to have them in your garden. However, forcing tulips to enjoy inside during the long, dreary days of winter is also fun. Place bulbs close together in a pot, but not touching. Cover with soil so the bulb tips are at the surface. Water well. Place the pot in an unheated garage (32-50 degrees) or refrigerator for about 12-14 weeks. When the bulbs begin to sprout, set them in a warmer spot (50-65 degrees is ideal) with bright, indirect light for one to two weeks. When the sprouts are 2 inches, set the pot near a sunny window. Plants will bloom in two weeks. Keep the pot out of direct sunlight when the plants are blooming to prolong blooms. Discard the bulbs after the plants have bloomed.

November Garden Tips

• Protect your tree trunks and shrubs from rabbit and vole browsing during the winter with plastic tree guards or hardware cloth tall enough to accommodate deep snowfalls. Bury the bottom edge in the soil 2 to 3 inches to prevent rabbits from digging underneath. Remove them in the spring.

• It's time to take your amaryllis out of the dark and place in a bright window. Cut back any dead foliage and water it. Flowers typically develop in four to six weeks. Or, start amaryllis by potting new bulbs in containers just a little wider than their diameter. Water thoroughly and place them in a sunny window. Move them out of direct sun once buds open so they last longer.

• Rake, bag, blow and/or mow leaves to remove them from your lawn. Excessive leaf cover of more than 20 percent may smother grass and inhibit spring growth. It may also promote snow mold disease and create a nice habitat for mice and voles. Use the leaves as mulch over bulb and perennial beds or chop them up and put them in a compost pile.

• Mulch bulbs and flowering perennials by mid-November, even if the soil hasn't frozen yet. You can even spread straw, leaves or partially finished compost on top of snow. The most important function of mulch is to insulate roots from fluctuating temperatures. Snow is an excellent mulch but there is no guarantee it will remain in place all winter.

• Clean bird feeders, install squirrel guards and stock up on seed and suet. Birds add color and activity to your yard all winter and often stay in the spring to nest and raise their babies.

• Help reduce the spread of buckthorn by removing it from your property. They are easy to identify this month because they hold onto their leaves longer than other shrubs. Also, look for clusters of dried, blue-black berries and sharp barbs or thorns spaced sparsely on the branches. You may be able to pull up young seedlings with a strong pair of pliers; larger plants will require potent woody brush killers next spring.

• Move houseplants to brighter locations within your home to compensate for reduced light levels as the days grow shorter and cloudy weather increases. South or west facing windows are not too bright for low-light plants this time of year. Clean windows also let in more light. Pull shades or close drapes at night to protect houseplants from cold air near window panes. Rotate plants regularly to keep them growing symmetrically.

• Rake up infected leaves. Fungi survives the winter in infected leaves. Rake up and remove leaves from trees and shrubs suffering from leaf diseases, such as, apple scab, anthracnose, tar spot, black spot and powdery mildew.

• Store liquid garden products indoors where they will not freeze and change their chemical composition.

University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. All information given in this column is based on university research. To ask a question, call the Master Gardener Help Line at 218-454-GROW (4769) and leave a recorded message. A Master Gardener will return your call.