Frequently Asked Questions

Question:
What is cat grass?
Answer:

“Cat grass” is grown by cat owners to satisfy their cat’s desire to graze on green plants.  Cat grass is usually common oats or a blend of oats, wheat, and rye grass.  It is sold at pet supply stores and garden centers. 

Cat...

Question:
What are some good sources of flower and vegetable seeds?
Answer:

Flower and vegetable seeds can be purchased at local garden centers and other retailers. They’re also available from mail-order/internet companies.

Mail-order/internet sources include:

  • Park Seed Company |...
Question:
My onions don't store well. Why?
Answer:

The storage life of onions is largely determined by the variety (cultivar), harvesting and drying procedures, and storage conditions. 

When selecting onions, choose varieties that store well, such as ‘Copra’, ‘Stuttgarter’, and ‘Sweet...

Question:
How often should I water my poinsettia?
Answer:

The key to watering a poinsettia is the moisture content of the potting soil.  Check the potting soil daily with your finger.  When the soil surface becomes dry to the touch, water the plant until water begins to flow out the bottom of...

Question:
How can I raise the relative humidity indoors for my houseplants?
Answer:

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.  Humidifiers are an excellent way to increase the relative humidity...

Question:
How should I prune a newly planted tree?
Answer:

Trees utilize sugars and other carbohydrates manufactured by the foliage for plant growth.  Therefore, avoid the temptation to severely prune newly planted trees.  Severe pruning reduces the tree’s ability to manufacture food and...

Question:
Which plants are most likely to be damaged by browsing rabbits in winter?
Answer:

Trees and shrubs that are often damaged by rabbits in winter include crabapple, apple, pear, redbud, honey locust, serviceberry, burning bush or winged euonymus, flowering quince, barberry, roses, and raspberries. Small evergreens (especially...

Question:
My acorn squash turn yellow during storage. Why?
Answer:

The problem may be improper storage.  Acorn-type squashes should be stored at a temperature of 50 to 55 degrees Fahrenheit.  Some acorn-type squashes will turn yellow when stored at temperatures above 55 degrees Fahrenheit.  High...

Question:
My poinsettia has lost several leaves. What is the problem?
Answer:

Improper watering may be responsible for the leaf drop on the poinsettia.  Over-watering will cause the lower leaves to turn yellow and drop.  Plants that are allowed to get too dry will wilt and also drop leaves. 

The water...

Question:
How often should I fertilize houseplants?
Answer:

Spring and summer and the best times to fertilize houseplants.  Fertilizers are available in liquid, crystalline, granular, spike, and tablet forms.   Utilize fertilizers specifically formulated for houseplants or use general...

Question:
What is the proper way to prune a large tree branch?
Answer:

To prevent extensive bark damage, use a 3-cut procedure when pruning branches that are greater than 1½ inches in diameter.  Make the first cut 6 to 12 inches from the main branch or trunk.  Cut upward and go about one-third of the way...

Question:
What are the symptoms of deicing salt injury to trees and shrubs?
Answer:

The symptoms of salt injury to deciduous trees and shrubs include stunted growth, marginal leaf scorch, early fall coloration, and twig dieback. Accumulation of salt in the soil over several years may result in progressive decline and eventual...

Question:
How can I prevent rabbits from damaging my roses in winter?
Answer:

The best way to prevent rabbit damage to roses in the home landscape is to place chicken wire fencing or hardware cloth around the plants.  To adequately protect plants, the fencing material needs to be high enough that rabbits won’t be able...

Question:
What should I do with my poinsettia after the holidays?
Answer:

If given good care in the home, poinsettias should remain attractive for 2 to 3 months.  Toss the poinsettia when you grow tired of it or it becomes unattractive. 

Tips to have the poinsettia bloom again:

March to Late...

Question:
Should houseplants be fertilized in winter?
Answer:

Fertilization is generally not necessary during the winter months as most houseplants are not growing during this time.  Indoor gardeners should fertilize their houseplants on a regular basis in spring and summer when plants are actively...

Question:
Is it advisable to paint pruning wounds when pruning trees?
Answer:

Do not apply a pruning paint or wound dressing to pruning wounds.  The application of a pruning paint or wound dressing does not prevent wood decay and may actually interfere with the tree’s natural wound responses.

Oak trees are an...

Question:
How do I prevent desiccation injury to my yews and boxwoods?
Answer:

Narrow and broadleaf evergreens lose considerable amounts of moisture through their leaves or needles, buds, and stems during the winter months.  The loss of water is mainly due to strong winds and sun.  Once the ground freezes, however...

Question:
Which perennials are most likely to be heaved up out of the ground in winter?
Answer:

Repeated freezing and thawing of the soil during the winter months can lift up or heave some perennials out of the soil.  Heaving exposes the plant’s crown and roots to cold, dry air.  Perennials that have been heaved up out of the...

Question:
Is the poinsettia poisonous?
Answer:

The poinsettia has long been regarded as poisonous.  However, research conducted at various institutions has shown the poinsettia is not poisonous.  While the poinsettia is not poisonous, it is not intended for human or animal...

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:
When is the best time to prune oak trees?
Answer:

Winter (December through February) is the best time to prune oak trees in Iowa.  Pruning oak trees in winter greatly reduces the risk of an oak wilt infection. 

Oak wilt is a fungal disease that is lethal to many oaks.  It...

Question:
I have several small evergreens in my yard. Do I need to uncover the evergreens if they get buried in snow?
Answer:

No, there is no need to uncover the evergreens.  The snow will not suffocate the evergreens.  The snow acts like an insulating blanket and protects the evergreens from desiccating winter winds. 

Question:
It's November and I still haven't gotten my tulip bulbs planted. Should I plant them now or wait until spring?
Answer:

Plant the tulip bulbs as soon as possible.  Tulips and other spring-flowering bulbs can be planted as late as December if the soil isn’t frozen.  After planting, cover the area with several inches of straw, pine needles, or leaves....

Question:
I recently received a flowering azalea as a gift. How do I care for it?
Answer:

In the home, place the azalea in a brightly lit, cool location.  An ideal site is one near a window that receives bright light (but no direct sunlight) and temperatures of 60 to 65 degrees Fahrenheit. 

An important aspect of...

Question:
What is the proper care for a moth orchid?
Answer:

Lighting Requirements

Moth orchids (Phalaenopsis spp.) are one of the easiest orchids to grow indoors.  Moth orchids grow best in bright, indirect light.  Direct sun may actually harm the foliage.  Ideal sites are...

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