Frequently Asked Questions

Question:
Certain cool-season annuals, like mums, are also sometimes grown as perennials. Can I expect these plants to come back year after year?
Answer:

Cool-season annuals are annual plants that prefer cool temperatures, growing best in spring or fall. Many are tolerant of a light frost often surviving down to 28°F or sometimes even 25°F with little damage to flowers or leaves.

Plants...

Question:
When should I plant cool-season annuals?
Answer:

Cool-season annuals are annual plants that prefer cool temperatures, growing best in spring or fall. Many are tolerant of a light frost often surviving down to 28°F or sometimes even 25°F with little damage to flowers or leaves. They are great...

Question:
What cool-season annuals do well in Iowa?
Answer:

Cool-season annuals are annual plants that prefer cool temperatures, growing best in spring or fall. Many are tolerant of a light frost often surviving down to 28°F or sometimes even 25°F with little damage to flowers or leaves. They are great...

Question:
What are cool-season annuals?
Answer:

Annuals are a great way to add variety and color to the landscape and containers. As temperatures cool in late summer into fall, many of the summer annuals like marigolds, coleus and impatiens are looking “tired”. These annuals can be replaced by...

Question:
How should I prepare woody trees and shrubs for winter?
Answer:

While it may seem tempting, do not prune woody trees and shrubs in the fall. Pruning encourages new growth and when done in the fall, the new growth that develops will not be well hardened off for winter leading to more potential for winter...

Question:
How should I prepare my annual beds and containers for winter?
Answer:

Good fall clean-up is beneficial for containers and garden beds where annuals are grown to help prevent disease and pest issues as well as reduce unwanted reseeding of some annual species in future growing seasons. Consider planting...

Question:
How and when do I bring my houseplants back indoors after spending the summer outside before winter?
Answer:

Many of our houseplants enjoy a “summer vacation” spending the warm summer months outside in a full or part shade location. If you placed some of your indoor plants outside for the summer, you will need to move them back indoors before...

Question:
Can I use woodchips from black walnut as mulch in my landscape?
Answer:

Black Walnut is a common woodland and landscape tree in the Midwest that produces juglone which causes an allelopathic response (inhibition of growth) in other plants. When plants produce a chemical that prevents the growth of other plants, it is...

Question:
How long does juglone last in the landscape after the removal of a black walnut?
Answer:

Juglone is a chemical that inhibits the growth of certain plant species.  When plants produce a chemical that prevents the growth of other plants, it is called allelopathy.  Black Walnut is a common woodland and landscape tree in the...

Question:
What plants are sensitive to the juglone produced by black walnuts?
Answer:

Juglone is a chemical that inhibits the growth of certain plant species.  When plants produce a chemical that prevents the growth of other plants, it is called allelopathy.  Black Walnut is a common woodland and landscape tree in the...

Question:
Do I need to kill the grass or till the soil before starting a raised bed?
Answer:

Before filling raised beds, remove the grass sod, if possible, and work up the existing soil with a rototiller or spade.  Add a few inches of the soil mix, then incorporate it into the existing soil.  Continue to add and incorporate...

Question:
What are some pros and cons to growing vegetables in raised beds?
Answer:

Raised beds provide several advantages over conventional garden areas. Wet, poorly drained sites can be improved by constructing raised beds. A properly prepared raised bed increases drainage, thereby promoting plant growth and increasing crop...

Question:
Do I need to remove the leaves on my lawn?
Answer:

Turfgrass plants utilize light, water, and nutrients to manufacture food.  In fall, lawn areas beneath large trees are often completely covered with leaves.  The leaf debris prevents the turfgrass plants from manufacturing and storing...

Question:
I just seeded my yard, can I spray for broadleaf weeds?
Answer:

Most broadleaf herbicides should not be sprayed on newly seeded turfgrass until after the area has been mowed twice. You can start mowing a newly seeded area once the yard has grown to three inches tall, and you can mow it at 2 to 2.5 inches...

Question:
What organic options exist for controlling weeds in my garden?
Answer:

Mechanical control of weeds through hand pulling and cultivation as well as the use of mulches to suppress weed growth are effective organic options for weed management. 

Pouring boiling water on weeds can be used especially in...

Question:
How and when should herbicides be used for weed control?
Answer:

In certain situations, a gardener can use herbicides to supplement other weed control strategies. Several factors limit the usefulness of herbicides in the home garden. Most home gardens contain a variety of plants in a small area. This restricts...

Question:
How can mulches be used to control weeds?
Answer:

Mulches control weeds by preventing the germination of weed seeds. Established weeds should be destroyed prior to the application of the mulch. In addition to weed control, mulches help conserve soil moisture, reduce soil erosion, prevent...

Question:
How do I control weeds using mechanical means, such as cultivation or hand pulling?
Answer:

Cultivation and hand pulling effectively control most annual weeds. It is very important to destroy these weeds while they are small, before they produce thousands of seeds, guaranteeing a weed problem for many years in the future. Like annual...

Question:
How do I control weeds in my garden beds?
Answer:

Keeping ahead of weeds and controlling them when they are small is essential for good weed management. This requires persistence throughout the entire growing season to remove weeds as they emerge. There are essentially two types of weeds in our...

Question:
How do I store salsify?
Answer:

Harvest salsify in mid- to late November as cool fall temperatures enhance the oyster-like flavor of the roots.  After harvest, trim off the foliage 1 inch above the roots and store the salsify at a temperature of 32 degrees Fahrenheit and a...

Question:
Are there any trees or shrubs that bloom in winter?
Answer:

While most trees and shrubs bloom in spring or summer, witch hazels are a notable exception. Common witch hazel (Hamamelis virginiana) blooms from mid-October to early December.  Vernal witch hazel (Hamamelis vernalis) and...

Question:
Is canned pumpkin actually made from a mixture of butternut and other squashes?
Answer:

The terms pumpkin and squash are rather confusing.  Pumpkins are a member of the Cucurbitaceae family, which also includes squashes, cantaloupes, cucumbers, watermelons, and gourds.  A pumpkin is actually a type of squash.  The...

Question:
Are there ornamental grasses with colorful fall foliage?
Answer:

Several ornamental grasses develop good fall color.  Switchgrass (Panicum spp.) cultivars with colorful fall foliage include ‘Rehbraun’ (reddish brown), ‘Rotstrahlbusch’ (burgundy red), and ‘Prairie Fire’ (wine red).  In fall,...

Question:
I planted fountain grass in the garden this spring. Will it survive the winter?
Answer:

There are several species of fountain grass.  Perennial fountain grass (Pennisetum alopecuroides) is a perennial grass.  It is hardy in much of Iowa.  Annual fountain grass (Pennisetum setaceum) is a widely grown...

Question:
How do I store parsnips?
Answer:

Harvest parsnips in mid- to late November as cool fall temperatures convert starch to sugar and give parsnips their distinctive flavor.  After harvest, trim the foliage back to within 1 inch of the roots.  Store parsnips at a...

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