The Agent's Observations Nov 1997

Question: What is the proper care of an amaryllis houseplant?

Answer: The amaryllis houseplant is in the genus Hippeastrum, not be confused with the outdoor Amaryllis bella donna. Both are native to South Africa. Amaryllis should have several hours of sunlight or bright light all day. Keep the soil evenly moist and feed every other week, except during fell. What the strap like leaves turn yellow, dry out the plant for at least two months after removing the dried leaves. Keep the plant in a cool, dry, dark place, after this rest period repot the amaryllis, during late fall or early winter, in a sandy soil mix with bonemeal or super phosphate. Set the upper half of the bulb above the soil surface. Firm the soil and lightly water until growth restarts. Too much water can cause rotting. When leaves begin yellowing start the procedure over again. The large flower stock topped with two to six huge trumpet-shaped flowers make this long lived houseplant worth keeping!

Source: House Plants. 1980. The American Horticultural Society. Franklin Center, PA. Page 86.

Question: Should I fertilize and water my trees during the winter? How about my house plants?

Answer: Fertilizing of trees and shrubs during the winter in the high desert should not be done. Fertilizer could stimulate plants to come out of dormancy, new growth to begin and then winter damage could occur. These plants are "resting" above the ground but do have activity in the roots if soil temperatures are warm. Normally trees and shrubs that go into winter with adequate soil moisture do not need watering during the winter. Usually winter rains or snow provide enough water. With cold air and soil temperatures evergreens will use little water. Deciduous plants will not use any water because leaves have fallen and are not transpiring. However, if winter moisture is not sufficient to keep the roots moist they will die. Over the past two dry winters supplemental irrigation has been needed in Cochise County. If no winter moisture occurs for a month or six weeks then water. Many evergreen trees have died from winter moisture stress. The plant actually dies in the late spring as temperatures and water demands increase but the roots died during the winter. Without an adequate root system plants will not live.

Houseplants are generally tropical in origin and survive best in warm humid environments. Houseplants need to be watered because of the limited soil volume they are confined to. House temperatures are warm and allow plants to continue to grow. The best way to determine soil moisture is to stick a finger in the soil one to two inches. If the soil feels dry, water; if soil feels moist, don't water. Fertilizing houseplants during the winter months is not encouraged because of reduced light from the sun. However, if you are "spoon feeding" your plants, that is giving a little fertilizer at each watering, cut back on the fertilizer by giving to 1/4 to 1/2 the normal amount.

Many house plants need high humidity to be "happy." This is especially true with ferns. With forced air heating in many homes, house humidity can be lower during the winter than during the hot summer because of swap cooler use. Humidity can be created by placing the potted plant on top of a pebble filled shallow dish. Fill the dish with water as needed, maintaining the water level near the top. The dish should have a diameter nearly as large as the plant diameter. The pebbles are important so that the potted plant is not sitting in water which will cause soil saturation, and thus root rot. As the water evaporates a humid environment is created in which a tropical plant will grow and thrive. This is much better than using a squirt bottle three times a day to try and humidify the plant!

Author: 
Rob Call
Issue: 
November, 1997