Frequently Asked Questions
Hot, dry weather may be responsible for the leaf drop on the river birch. River birches shed some of their leaves in hot, dry weather. Leaves in the interior of the river birch turn yellow and drop to the ground. Healthy, well-...
“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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Proper pruning of purple raspberries promotes high yields, helps control diseases, and facilitates harvesting and other maintenance chores.
In March or early April, remove all small, weak canes, leaving only 4 or 5 of the largest,...
While marigolds are seldom bothered by insects and diseases, they are not problem free. Spider mites can devastate marigolds in hot, dry weather. Grasshoppers can also cause considerable damage. Aster yellows is an occasional...
Chinese cabbage performs best when planted in summer for a fall crop. (Chinese cabbage frequently goes to seed when planted in spring.) Sow the seed of Chinese cabbage at a depth of 1/4 to ½ inch in July. Rows should be spaced 2...
Cut back peony foliage after it has been destroyed by a hard freeze. In Iowa, late October or early November is generally a good time to cut back peonies. Cut off the stems near ground level. If the peonies experienced foliar...
The small size of “baby” corn suggests that it’s a special variety. However, most baby corn is actually grown from regular sweet and field corn varieties. The ears are harvested when they are 2 to 4 inches long and 1/3 to ½ inch in...
The magic lily (Lycoris squamigera) is a rather intriguing plant. Other common names include resurrection lily, surprise lily, hardy amaryllis, and naked lady. The life cycle of Lycoris squamigera is different from...
The moisture content of popcorn determines its popping quality. The ideal moisture content of popcorn is 13 to 14.5 percent.
Popcorn should be left on the stalk until fully mature. Harvest the ears when the husks are...
Bagworms are caterpillars that live inside spindle-shaped bags. (The bags somewhat resemble small Christmas tree ornaments hanging from the tree.) Bagworms feed on the foliage of a wide variety of trees and shrubs. However, they...
After seeding, keep the upper 1 inch of soil moist by watering once or twice a day. With adequate moisture and warm soil temperatures (55 degrees Fahrenheit or above), the seeds of most turfgrasses should germinate in 2 to 3 weeks....
Early in the 1900's, white pine blister rust (Cronartium ribicola) became a serious disease problem in the United States. White pine blister rust requires both a currant or gooseberry (Ribes species) and white pine to...
In Iowa, the foliage of the river birch (Betula nigra) often turns a sickly yellow-green. The yellow-green foliage is due to a deficiency of iron. The problem is referred to as iron chlorosis. (A close examination of chlorotic leaves...
Before applying any herbicide, carefully read and follow label directions. When applying liquid formulations, potential spray drift problems can be avoided by following simple precautions. Don’t spray when winds exceed 5 mph....
Suggested raspberry varieties for Iowa include:
Summer-Bearing Red Raspberries for Iowa
- ‘Boyne’
- ‘Latham’
- ‘Killarney’
Fall-Bearing Red Raspberries for Iowa
...Marigolds do not repel rabbits, deer, or other animals. In fact, rabbits occasionally browse heavily on marigolds. Erecting a chicken wire or hardware cloth fence around the vegetable garden is the best way to keep rabbits out of the...
Harvest cucumbers every 2 to 3 days and promptly pick the fruits when they reach the desired size. Pickling varieties should be harvested when the fruits are 2 to 4 inches long. Slicing cucumbers should be 6 to 8 inches long and 1.5...
Powdery mildew is a common disease of garden phlox (Phlox paniculata). The fungal disease produces a grayish white coating on the leaves. Infected leaves eventually turn yellow and then brown. Initial symptoms appear on...
Poorly filled ears are usually the result of poor pollination. Hot, dry winds and dry soil conditions may adversely affect pollination and fertilization and result in poorly filled ears. Water sweet corn during pollination if the soil is...
Individuals wishing to save their Easter lily (Lilium longiflorum) should place the plant in a sunny window after flowering. Continue to water the plant when needed. Fertilize once every 2 weeks with a dilute fertilizer...
It would be best to place weeds that are producing seeds and diseased plant debris in biodegradable bags and have the material picked up and composed by a municipal or commercial composting facility. The temperatures in home compost piles...
The browning of the honey locust foliage is probably due to the mimosa webworm. Damage occurs when the caterpillars tie honey locust leaflets together and feed on the foliage inside the tightly compressed, protective webs. Affected...
A newly sodded lawn should be watered once or twice a day for the first 7 to 10 days. Apply enough water to moisten the sod and upper 1 inch of soil. The sod should root to the soil in about 10 days. At this point, gradually...
Jostaberries are a cross between black currants and gooseberries. Plants are vigorous and may grow to a height of 6 to 8 feet. Jostaberry fruit are similar in size to gooseberries and black in color. Plants possess excellent...
The browning of the inner foliage is probably due to seasonal needle drop. It’s normal for evergreens (pine, spruce, fir, juniper, arborvitae, etc.) to shed their oldest (innermost) needles in fall. The innermost needles gradually turn yellow or...