Many peony plants produce few, if any, flowers the first spring. In fact, it’s advisable to pinch off any flower buds that develop the first spring to promote root and foliar growth. Flower bud development requires a great deal of the…
The roots of trees continue to grow until the ground freezes. If the weather is dry, continue to water the newly planted trees until the soil freezes in winter.
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…
During the first growing season, all the blossoms should be removed from June-bearing strawberries. If the flowers are allowed to develop into berries, their development will reduce plant growth, runner production, and the size of next year…
The hydrangeas found in flower shops are bigleaf hydrangeas forced into bloom out of season. These plants are intended to be enjoyed as a temporary potted plant indoors, much like poinsettia, and are not intended for planting in the landscape.…
In the home, place the mum 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 70°F.
Tulips, daffodils, hyacinths, and other spring bulbs are frequently available from florists and garden centers in winter. When purchasing these potted forced spring bulbs, select those that have fully developed buds but have not yet opened…
Early spring (before leaves emerge) and fall (after leaf drop) are the best times to transplant deciduous trees. Evergreens are most successfully transplanted in early spring and late summer (late August to mid-September).
Pollination and fertilization are necessary for fruit development. Pollination is the transfer of pollen from the anther to the stigma. Fertilization is the union of the male sperm nucleus from the pollen grain and the female egg…
Purchase virus-free raspberry plants from a reliable garden center, nursery, or mail-order company. Plants obtained from an old patch are often diseased. Virus-infected plants may appear healthy, but grow and yield poorly. …
Using a well-drained growing medium, sow onion seeds in flats approximately 8 to 10 weeks before you intend to plant them outdoors. As soon as the seeds germinate, place the onion seedlings under artificial lighting. An ordinary…
Many lily enthusiasts don’t grow tiger lilies (Lilium tigrinum) because they are often infected with lily mosaic virus. Lily mosaic virus causes little harm to tiger lilies. Oftentimes, you can’t tell that they have the…
Determinate and indeterminate refer to the tomato’s growth habit. Determinate tomatoes are small, compact plants. They grow to a certain height, stop, then flower and set all their fruit within a short period of time. The…
Pollination is the transfer of pollen from the anther to the stigma. After pollination and fertilization, fruit set occurs. There are two types of pollination. Self-pollination occurs when the pollen is transferred from the…
The browning of the peony buds is likely due to botrytis blight. Botrytis blight is a common fungal disease of peonies. The fungus Botrytis paeoniae attacks stems, leaves and flower buds. It is most common in cool, rainy weather.
In the past, some gardeners used salt to control weeds in their asparagus plantings. However, salt is not effective in controlling many weeds, especially grasses. Plus, continued use of salt over several years may result in high salt…
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.
Deadheading is the removal of spent flowers. While tulips should be deadheaded immediately after flowering, it is not necessary to deadhead daffodils. The vigor of tulip bulbs quickly declines if tulips are not promptly deadheaded and…
Peonies do not need to be divided on a regular basis. Peonies can be left undisturbed in the garden for 50 or more years. However, large peonies can be divided if you want additional plants.
Cannas are normally grown from rhizomes. However, it is possible to grow cannas from seeds. Canna seeds have hard seedcoats. Prior to sowing, soak the seeds in water for 24 hours. Sow the seeds in a commercial germination…
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…
The frequency of mowing should be based on the growth of the grass. As a general rule, mow as often as needed so that no more than one-third of the total leaf area is removed in a single mowing. Removing more than one-third is detrimental…
After freezing temperatures, some gardeners express concerns about the edibility of rhubarb. Rhubarb is a tough plant. Temperatures in the upper twenties or low thirties usually cause little or no damage. A hard freeze (…
Don’t worry. The balloon flower (Platycodon grandiflorus) is slow to emerge in spring. Other late emerging perennials include hardy hibiscus (Hibiscus hybrids), butterfly weed (Asclepias tuberosa), and…
The rose-of-sharon (Hibiscus syriacus) can be successfully grown in the southern half of Iowa. (It’s hardy in USDA Hardiness Zones 5 to 9.) The rose-of-sharon leafs out late in spring. In Iowa, plants may not leaf out until…
The symptoms are those of peach leaf curl. Peach leaf curl is a fungal disease. The disease is caused by the fungus Taphrina deformans. Infections occur as the peach tree buds begin to swell in spring.
Forsythias bloom on old wood. Unfortunately, the flower buds on some varieties are not reliably cold hardy in Iowa. For example, the flower buds on 'Lynwood Gold' and 'Spring Glory' are hardy to minus 10 degrees Fahrenheit. Since most areas…
The leaf drop is probably due to anthracnose. Anthracnose is a common fungal disease of trees in Iowa. Anthracnose may occur on ash, sycamore, maple, oak, walnut, and other deciduous trees (see encyclopedia article…
