There are more than 900 species and innumerable cultivars of azaleas and rhododendrons. However, only a small number perform well in Iowa. To be successful, the Iowa gardener must select cold hardy cultivars, choose suitable planting…
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…
This is a difficult question to answer because the growth rate of any plant depends on site conditions and maintenance. In most cases, the growth rate given for a particular plant is based on optimal conditions. Quite frequently, however, our…
The majority of roots, especially those roots that are responsible for water and nutrient uptake, are in the upper 6 to 18 inches of soil. Structural roots that radiate out from the tree and provide support and anchorage can reach a…
Fruit trees purchased from nurseries and garden centers are usually 1- to 2-year-old plants. The length of time from planting to fruit bearing varies with the species of fruit, the cultivar, and whether the tree is dwarf or standard.…
Purple, black, and summer-bearing red raspberries that have been badly damaged by rabbits will likely produce little fruit this year. (Purple, black, and summer-bearing red raspberries produce fruit on the previous year's shoots. …
Shade trees endemic to Iowa or similar ecoregions are listed below. These species can be found east of the Rocky Mountains in North America and Canada. Those native to within Iowa's boundaries are noted with an asterisk (*). …
These shrubs are found east of the Rocky Mountains in North America and Canada. They are hardy to USDA Hardiness Zones 4 or 5. Those native to within Iowa's boundaries are noted with an asterisk (*).
Small ornamental trees endemic to Iowa or similar ecoregions are listed below. These species are less than 30 feet tall and are found east of the Rocky Mountains in North America and Canada. They are hardy to USDA Hardiness Zones 4 or 5.…
The Emerald Ash Borer (EAB) is an exotic destructive pest that kills all native ash trees (Fraxinus). The loss of ash trees significantly impacts the urban tree canopy. While treatment options are available, some trees cannot be treated…
Cherries perform best in moist, well-drained, fertile soils. Avoid wet, poorly drained sites. Cherries are susceptible to root rots in wet, poorly drained soils. Trees should also receive full sun. Sites must receive at…
Modern roses, such as hybrid tea, grandiflora, and floribunda roses, are propagated by budding. A single bud is removed from the desired variety and inserted onto a hardy rootstock. The bud union (the knob-like swelling at the base of…
Gooseberries and currants are small to medium-size shrubs that may reach a height of 3 to 6 feet. Gooseberries and currants should be planted 4 to 5 feet apart. Rows should be spaced 6 to 8 feet apart.
When planting a container-grown tree, dig a hole that is 2 to 3 times wider than the diameter of the container. The depth of the hole should be 2 or 3 inches less than the height of the soil ball. Slope the sides of the hole so the…
In March or early April, remove all small, weak canes, leaving only 4 or 5 of the largest, most vigorous canes per clump or plant. Cut back the lateral (side) branches to 12 inches in length.
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 Midwest that produces an allelopathic compound called juglone which is…
Several species of shrubs can help get your spring off to a colorful start. These multi-stemmed woody plants vary in size and often bloom before the leaves emerge in spring.
While most deciduous trees have flowers of some kind in springtime, they tend to be small and not showy. There are several species of smaller, ornamental trees that have showy blooms in the spring.
Noticeable symptoms of emerald ash borer usually appear in the second or third year of the infestation or later. Emerald ash borer infested trees exhibit thinning of the leaf canopy and dieback in the crown. Also, infested ash trees…
Forsythias bloom on the previous year’s growth. The best time to prune forsythias is immediately after flowering. Pruning forsythias anytime from mid-summer until just prior to bloom will reduce flowering in spring. When pruning…
