Frequently Asked Questions
Browning of yews in late winter or early spring is usually the result of desiccation injury. Evergreen foliage continues to lose moisture during the winter months, particularly on windy or sunny days. However, once the soil freezes, the plant’s...
Tree peonies are small woody shrubs. Unlike herbaceous peonies, the stems of tree peonies do not die back to the ground in fall. Tree peonies can be successfully grown in USDA Hardiness Zones 4 to 8.
Cold winter...
Grape hyacinths (Muscari spp.) are spring-flowering bulbs. They produce urn-shaped flowers on 6- to 9-inch-long, upright spikes. (The flower spikes somewhat resemble clusters of grapes, hence the common name.) Flowers...
The asparagus foliage can be cut back to the ground after it has been destroyed by cold temperatures in fall. However, it is generally recommended that the dead foliage be allowed to stand over winter. The dead debris will catch and...
Many houseplants prefer a relative humidity of 40 to 50 percent. Unfortunately, the humidity level in many homes during the winter months may be only 10 to 20 percent.
Misting houseplants is not an effective way to raise the...
Late March or April is the best time to plant dormant, bare-root raspberry plants in Iowa. If the planting of dormant, bare-root raspberry plants must be delayed after purchase, moisten the packing material around the roots of the raspberry...
As the name suggests, bare-root trees and shrubs have no soil around their roots. Bare-root nursery stock is dug in late fall, placed in cold storage, then shipped to garden centers or gardeners in early spring. Bare-root trees and...
Since potatoes are susceptible to several serious diseases, buy certified, disease-free potatoes at garden centers and mail-order nurseries. Potatoes that remain from last year's crop may carry undetectable diseases. Potatoes...
Tall, spindly growth is a common problem when growing transplants indoors. Poor (insufficient) light, excessive watering, high temperatures, excessive fertilization, and crowded conditions are factors that contribute to spindly growth.
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Several steps can be taken to minimize disease problems in your garden next year.
Fall Clean-Up
An important task is to clean up the garden in fall. Carefully remove and destroy the infected plant debris. Many of the...
Construction of buildings, patios, garages, driveways, sidewalks, and roads often compromises the growing environment of nearby trees. The majority of a tree’s roots are located in the top 12 to 18 inches of soil and often extend well...
The brightly colored flowers of moss phlox (Phlox subulata), oftentimes referred to as “creeping phlox,” are a common sight in many home landscapes in spring. Moss phlox forms dense, carpet-like mats. Plants are 4 to 6 inches...
The Martagon lily (Lilium martagon) is one of the most widely distributed lilies in the world. It grows naturally in most of Europe and parts of Asia. It is also referred to as Turk’s cap lily.
The Martagon lily...
Gooseberries should be pruned to maximize fruit production. Gooseberries produce the majority of their fruit on two- and three-year-old shoots. Shoots 4 years old and older produce very little fruit. Pruning of mature,...
For the indoor gardener, a fluorescent light fixture containing two 40 watt tubes (one cool white and one warm white) provides adequate light for houseplants. Plant lights, developed specifically for growing plants indoors, are another...
To reduce the chances of crop damage from a late frost or freeze, leave the mulch on as long as possible. Removing the mulch in March may encourage the plants to bloom before the danger of frost is past. Temperatures of 32 degrees...
Early spring (before bud break) is the best time to transplant evergreens. Evergreens can also be transplanted in late summer (late August to mid-September). Evergreens transplanted after mid-September may not have adequate time to...
Small potato tubers may be planted whole. Large potatoes should be cut into sections or pieces. Each seed piece should contain one or two “eyes” or buds and weigh approximately 1.5 to 2.0 ounces. After cutting the tubers into...
Damping-off is probably responsible for the collapse and death of your seedlings. Damping-off is caused by several different fungi. Environmental conditions associated with damping-off are poorly drained potting soil, overcrowding, and excessive...
Store lawn and garden fertilizers in their original bags or containers so you will know the content and analysis of the product next season. Store granular fertilizers in a protected location where they will remain dry. Granular...
Trees have shallow roots. The vast majority of a tree’s roots are located in the top 12 to 18 inches of soil. As the tree roots grow, some of the larger roots near the soil surface may emerge from the ground. While many individuals regard...
Jack-in-the-pulpit (Arisaema triphyllum) seeds can be sown directly outdoors or started indoors. Harvest the cluster of berries as soon as they turn red in late summer. Each berry usually contains 4 to 6 seeds. Remove...
The white material on the foliage of your African violets is probably powdery mildew. Powdery mildew is a fungal disease that is common on indoor plants, such as African violets, begonias, and poinsettias. Outbreaks of powdery mildew...
The best time to plant dormant, bare-root grapevines in Iowa is early spring (late March and April). If planting must be delayed for several days after purchase or their arrival in the mail, moisten the packing material around their roots,...
Cleaning houseplants improves their appearance, stimulates growth, and may help control insects and mites. Large-leaved plants may be cleaned with a mild dishwashing soap solution (add a few drops of dishwashing soap to lukewarm water) and...