Frequently Asked Questions
The best time to divide perennials varies with the different plant species. While most perennials are best divided in early spring, late summer/early fall (September in Iowa) is a good time to dig and divide peony, daylily, garden phlox, hosta,...
There are different ways to classify or categorize plants and plant structures. Botanically, the typical plant has roots, stems, leaves, flowers, and fruit. The root is the edible portion of carrots, radishes, beets, and parsnips....
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 ...
Bell peppers are usually harvested when large, firm, and dark green (immature stage). They may also be allowed to fully ripen to red, yellow, orange, or other colors. Fully mature bell peppers are slightly sweeter and contain higher...
Blueberries can be successfully grown in Iowa. However, they do have special growing requirements.
Blueberry plants require a sunny location and a well-drained soil high in organic matter. Avoid wet, poorly drained sites...
Oak wilt is a serious disease that can infect many oak species. It is caused by the fungus B. fagacearum. Red and pin oaks are very susceptible to the oak wilt fungus and can die within 4 to 6 weeks. White and bur oaks...
Kentucky bluegrass lawns should be mowed at the height of 2½ to 3 inches in spring and fall. Set the mower blade to a height of 3 to 3½ inches during summer.
As a general rule, never remove more than 1/3 of the total leaf...
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...
American holly (Ilex opaca) and English holly (Ilex aquifolium) are prized for their glossy, green leaves and brightly colored fruit. Sprigs of both hollies are often used in wreaths, centerpieces, and other Christmas...
The yellow-green bugs are probably the adults of the northern corn rootworm. The larvae of the northern corn rootworm feed on the roots of corn plants. The adults (yellow-green beetles) appear in mid-summer and are present until frost...
In windy, exposed areas, straw mulches can be kept in place by placing wire or plastic fencing over the area. The fencing can be held in place with bricks or other heavy objects.
Peas are members of the legume (Fabaceae) family. Through a symbiotic relationship with a soil bacterium (Rhizobium), peas are able to “fix” atmospheric nitrogen in nodules on their roots.
Peas will grow and produce a crop...
The iris borer is a serious pest of bearded irises. The mature stage of the iris borer is a grayish moth. Female moths lay eggs on iris foliage and other nearby plants in late summer/early fall. The eggs hatch the following...
Radishes can be planted as soon as the ground can worked properly in spring. This is often late March in southern Iowa and mid-April in northern counties. Successive plantings can be made every 7 to 10 days through May. Radish...
The growth in your perennial bed is probably a slime mold. Slime molds are types of fungi. Slime molds feed on bacteria and other organisms in the mulch. They do not harm plants.
Slime molds are usually a temporary nuisance. Within a few...
The curling of the tomato leaves may be a physiological disorder referred to as leaf roll. Affected leaves roll upward and inward. The leaves may also become thickened, giving the foliage a leathery appearance.
Leaf roll...
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...
Drying peppers is a simple procedure. Harvest mature peppers (the fruit of most varieties turn from green to red at maturity), wash to remove any dirt, then allow the fruit to dry for a few minutes on the kitchen counter. Once the...
Birds are the biggest threat to the blueberry crop in the home garden. If not controlled, hungry birds may devour most of the crop. Scare devices are sometimes helpful. However, netting is the most effective way to protect the...
The ‘Sunburst’ honeylocust has distinctive yellow-green foliage. Unfortunately, it is not a vigorous tree. It grows slowly and is susceptible to cankers and mimosa webworms.
Cankers, caused by fungal pathogens, are localized...
When the lawn is mowed properly, grass clippings do not need to be removed or bagged. Small clippings filter down into the turf and quickly decompose, returning essential plant nutrients to the soil. Lawn clippings do not...
Brown rot is a common fungal disease of peaches and other stone fruits. Affected fruits develop circular light brown spots that expand rapidly and rot the fruit. Sometimes the fungus that causes this rot is visible as ash-gray tufts....
The large, hard growth is probably crown gall. Crown gall is caused by the bacterium Agrobacterium tumefaciens. The bacterial disease can infect roses, grapes, apples, raspberries, willows, euonymus, and many other woody...
In the midwest, yield is largely determined by weather conditions. Lima beans grow best when temperatures are between 70 and 80 degrees Fahrenheit. They also require 1 inch of water per week (either from rain or irrigation) during...
September is the best time to divide peonies. By September, peony plants have been able to store adequate food reserves in their roots. Also, the replanted divisions have several weeks to get reestablished at their new sites before...