Frequently Asked Questions

Question:
When planting potatoes, do I need to purchase certified seed potatoes?
Answer:

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...

Question:
The flower and vegetable plants that I started indoors getting tall and spindly. Why?
Answer:

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.

...

Question:
How can I minimize plant disease problems in my vegetable garden next year?
Answer:

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...

Question:
What effects will construction activities have on nearby trees?
Answer:

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...

Question:
What are suitable planting sites for creeping phlox?
Answer:

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...

Question:
What are Martagon lilies?
Answer:

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...

Question:
How should I prune my gooseberries?
Answer:

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,...

Question:
When can I plant grapevines in my garden?
Answer:

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,...

Question:
Will standard fluorescent bulbs provide sufficient light for houseplants?
Answer:

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...

Question:
When should I remove the mulch on my strawberry bed?
Answer:

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...

Question:
When would be a good time to move an evergreen tree with a tree spade?
Answer:

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...

Question:
When cutting potato tubers into pieces prior to planting, what is the proper size for the sections?
Answer:

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...

Question:
Some of the seedlings that I start indoors collapse and die shortly after germination. Why?
Answer:

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...

Question:
What is the best way to store an opened bag of lawn fertilizer?
Answer:

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...

Question:
There are several large surface roots around my shade tree. Can I safely cover these roots with soil?
Answer:

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...

Question:
How do I germinate Jack-in-the-pulpit seeds?
Answer:

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...

Question:
There are some white blotches on my African violet leaves. What are they and how can the problem be controlled?
Answer:

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...

Question:
How do you construct a grape trellis?
Answer:

Construction of a grape trellis is similar to constructing a farm fence.  The trellis must be substantial enough to carry the weight of the vines plus a heavy crop during high winds.  Basically, the trellis consists of two or three...

Question:
Dust has accumulated on the foliage of my houseplants. How can I clean the plants?
Answer:

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...

Question:
What would be a good planting site for strawberries?
Answer:

When selecting a planting site, choose an area that receives full sun and has a well-drained soil.  Planting sites should receive at least 6 hours of direct sun per day.  Leaf and root diseases are often problems in poorly drained, wet...

Question:
When is the best time to transplant an azalea?
Answer:

Early spring (before the shrub begins to leaf out) would be the best time to transplant an azalea.  In Iowa, this is normally sometime from late March to mid-April.  An azalea transplanted in fall (after leaf drop) would be susceptible...

Question:
When should I plant potatoes in the garden?
Answer:

Potatoes should be planted in early spring.  Appropriate planting times are late March or early April in southern Iowa, early to mid-April in central Iowa, and mid to late April in northern portions of the state. 

Since potatoes...

Question:
The seedlings that I have started indoors are yellow-green in color. What should I do?
Answer:

The yellow-green color is likely due to a nutrient deficiency. Nitrogen and phosphorus deficiencies sometimes occur when flower and vegetable seedlings are started indoors. Symptoms of a nitrogen deficiency include yellow-green foliage and...

Question:
How do I control water grass in my lawn?
Answer:

“Water grass” is an ambiguous name.  Several plants are occasionally referred to as water grass.  Two common lawn weeds that are sometimes referred to as “water grass” are crabgrass and yellow nutsedge. 

Crabgrass

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Question:
How can I prevent damage to trees and shrubs from deicing salts?
Answer:

Homeowners can minimize salt damage by using deicing salts prudently. Before applying salt, wait until the precipitation has ended and remove as much of the ice and snow as possible. Use deicing salts at rates sufficient to loosen ice and snow...

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