Frequently Asked Questions

Question:
Can I grow an apple tree from a seed?
Answer:

It is possible to grow an apple tree from an apple seed.  However, in most cases, apple trees don't come true from seeds.  For example, a seed taken from a Red Delicious apple will not produce a Red Delicious apple tree.  Seedling...

Question:
How do you care for a cineraria?
Answer:

The cineraria (Pericallis x hybrida) is a flowering plant typically sold at floral shops and other retailers from mid-winter to early spring.  Plants produce clusters of 1- to 3-inch-diameter, daisy-like flowers.  They...

Question:
What is the proper way to prune grapevines?
Answer:

Grapevines produce fruit clusters on the previous season’s growth.  Before pruning, a grapevine may have 200 to 300 buds capable of producing fruit.  If the vine is not pruned, the number of grape clusters would be excessive and the...

Question:
What are the benefits of compost?
Answer:

Incorporating compost into garden soil improves the physical, chemical, and biological properties of the soil. For example, adding compost to garden soil increases the moisture-holding capacity of sandy soils and improves the drainage and...

Question:
When should I apply a dormant oil spray to my fruit trees?
Answer:

Dormant oil sprays are highly refined petroleum products that are mixed with water and applied to trees and shrubs to control aphids, spider mites, and scale.  Dormant oils destroy pests by suffocating them.  When applied properly, the...

Question:
When would be the best time to prune potentillas?
Answer:

Summer-flowering shrubs, such as potentilla and Japanese spirea, bloom in summer on the current year’s growth.  Prune summer-flowering shrubs in late winter or early spring (March or early April in Iowa).

Question:
When can I divide rhubarb plants?
Answer:

Early spring is the best time to divide rhubarb plants.  Dig up plants as soon as the ground can be worked in spring.  Divide each plant into sections with a large knife or spade.  Each section should have at least 2 or 3 buds or...

Question:
What is the optimum temperature when germinating seeds indoors?
Answer:

Most flower and vegetable seeds germinate best when the temperature of the germination medium (potting mix) is 70 to 75 degrees Fahrenheit. 

Question:
How should I prune hybrid tea roses in spring?
Answer:

The upper portions of hybrid tea, grandiflora, and floribunda roses typically die due to exposure to low winter temperatures and extreme temperature changes.  When the winter protection is removed from these roses in early spring (late March...

Question:
Should I fertilize established trees and shrubs?
Answer:

It is generally not necessary to fertilize healthy, vigorous trees and shrubs in the home landscape.  Most landscape soils in Iowa contain adequate levels of nutrients for trees and shrubs.  Plus, trees and shrubs that are growing in...

Question:
What are some good, long-lived perennials?
Answer:

When selecting perennials for the home landscape, it’s important to consider their size, bloom period, hardiness, and cultural requirements.  Another consideration is their longevity.  Some perennials are short-lived.  Short-lived...

Question:
Should blueberry plants be fertilized?
Answer:

Established blueberry plants benefit from an annual application of an acid-producing fertilizer, such as ammonium sulfate.  In early spring, apply ½ to 1 pound of ammonium sulfate per 100 square feet of garden area.  Ammonium sulfate...

Question:
How do you care for a gloxinia?
Answer:

The gloxinia (Sinningia speciosa) is a flowering houseplant related to the African violet.  Plants produce large, velvety, bell-shaped flowers that may be white, pink, red, purple, or blue.  Gloxinias are commonly sold at...

Question:
How can I propagate a grapevine?
Answer:

While grapevines can be propagated by several methods, they are most commonly propagated by hardwood cuttings.  Hardwood cuttings are made from the dormant canes of the preceding year’s growth. Cutting material should be collected in late...

Question:
Can I dispose of my wood ashes in the garden?
Answer:

Wood ashes contain small amounts of several plant nutrients. The nutrient content of wood ashes depends on the type of wood burned, the thoroughness of its burning, and other factors. Generally, wood ashes contain 5 to 7 percent potash, 1 percent...

Question:
When should I prune my fruit trees?
Answer:

Late February to early April is the best time to prune fruit trees in Iowa.  Summer pruning of fruit trees is generally not recommended.  However, water sprouts (rapidly growing shoots that often develop just below a pruning cut) can be...

Question:
My potentillas have gotten scraggly. What is the best way to prune them?
Answer:

Mature potentillas are often scraggly in appearance.  The best way to renew or rejuvenate scraggly potentillas is to prune them back to within 3 to 4 inches of the ground in late winter/early spring (March or early April in Iowa).  The...

Question:
What are the best rhubarb varieties for home gardens?
Answer:

These cultivars have attractive red stalks and are good choices for Iowa gardens: 

  • ‘Canada Red’
  • ‘Crimson Red’
  • ‘MacDonald’
  • ‘Valentine’

In addition to the previous four, there is a reliable...

Question:
How do I prevent rabbits from damaging plants in the vegetable garden?
Answer:

The most effective way to prevent rabbit damage in the vegetable garden is by placing chicken wire fencing or hardware cloth around vulnerable plants. Fencing material that is 2 foot tall should be adequate. Support the fence with wooden stakes...

Question:
I placed soil around the base of my hybrid tea roses in fall. When should I remove the soil?
Answer:

Remove the soil in late March or early April in southern Iowa, mid-April in northern portions of the state.  A frost or freeze in early spring shouldn’t harm the roses. 

After removing the soil, prune out any dead wood. ...

Question:
What are some good low-growing groundcovers?
Answer:

Plant heights vary somewhat based on the growing conditions at the site.  However, there are several groundcovers that are 12 inches or less in height. 

Shade Groundcovers

Low-growing groundcovers for shade include:...

Question:
What is the proper way to prune blueberries?
Answer:

Early spring is the best time to prune blueberries.  In Iowa, late March or early April would be an appropriate time to prune blueberries. 

Young plants require little pruning.  Pruning of young plants mainly consists of...

Question:
I recently purchased a primrose at a florist. How do I care for it?
Answer:

Primroses (Primula species) are typically sold at florist shops and greenhouses in late winter or early spring.  Plants produce attractive, 1- to 1½- inch-diameter flowers above a rosette of leaves.  Flowers may be white,...

Question:
Are there any peach varieties that can be successfully grown in Iowa?
Answer:

Peaches are not reliably cold hardy in most parts of Iowa.  It is possible to grow ‘Reliance’ (yellow flesh, freestone) and ‘Polly’ (white flesh, clingstone) in the southern one-third of Iowa. 

Growing peaches in Iowa is...

Question:
How do I have my garden soil tested?
Answer:

Soil testing services are provided by neighboring universities and private laboratories.  Information on how to collect good soil samples for testing and recommendations for how to find testing laboratories can be found at ...

Pages