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Sphaeropsis Tip Blight

A common cause of tip dieback (end of branches turn brown and die) on pines is the fungal disease Sphaeropsis tip blight. It is most common on Austrian pine, but also damages mugo, Scots and red pine. Other conifers are sometimes affected, especially when water stressed. This disease tends to be a problem on older, well-established trees, and rarely affects trees that are under 15 years of age.

Control:

• Minimize tree stress: plant properly on a good site; water deeply during dry periods; mulch.
• Prune out infected branches 6-8” below the point of infection, only when weather is dry.
• Remove pine cones which harbor spores that can cause new infections.
• Apply fungicides every 14 days from bud break until the new growth is fully expanded.
• Avoid planting susceptible tree species where the disease is prevalent.

Chinch Bug

Chinch bugs are small insects that feed on turfgrass. Damage is usually first noticed during hot, dry weather when irregular patches of grass begin to turn yellow, then straw colored. The patches increase in size in spite of watering.

The immature insects are first bright orange, eventually changing to black. Adults are black and white. They spend the winter in lawn thatch and become active when temperatures reach 70°F. The bugs feed on grass stems, blocking water and food movement so the leaves withers.

Control:

• Watering the grass helps drown immatures and encourages growth of fungi that kill the bugs. It will also help slightly damaged turf recover.
• Avoid planting perennial ryegrass and fine fescues that chinch bugs prefer.
• Use insecticides when populations reach damaging levels and chinch bugs are identified.

Why Mulch?

Mulches provide many benefits to plants, as well as making landscapes more attractive, usable and reducing maintenance.

• Controls weeds. You spend less time weeding and your plants don’t have as much competition for water and nutrients.
• Keeps the soil moist.
• Keeps soil temperatures more even — warmer at night and in the fall, cooler during the day, and in the summer.
• Adds nutrients as it decomposes.
• Reduces top soil loss by wind and rain erosion.
• Prevents soil compaction.
• Help to reduce some plant diseases.

Some good materials to use as mulch include shredded bark, compost, newspapers, untreated grass clippings, leaves, cocoa shells, and pine needles.

Peppers

There are many different varieties of peppers, ranging from sweet to very hot. Sweet bell peppers lack the capsaicin that gives hot peppers their pungency. Hot peppers (chiles) come in many colors, shapes and heat levels.

Peppers are temperature sensitive, so wait until the soil has warmed to at least 65°F (2-3 weeks after the last frost) before setting transplants out in full sun. Peppers are shallow-rooted, so cultivate carefully.

Peppers are ready to harvest when the fruit is glossy, firm and the desired color (they will not change color after picking). Stems should be firm and green and the skin should not be wrinkled. Picking the fruit will encourage the plant to set more fruit. Hot peppers develop the strongest flavor under hot, dry conditions and if allowed to remain on the plant until fully ripe.

Oak Wilt

Oak wilt disease is caused by a fungus (Ceratocystis fagacearum) that plugs the waterconducting tubes in a tree, preventing the transportation of water. Individual branches or the entire tree may wilt and die usually from late June through July. Leaves in affected trees turn dull green or bronze starting at the leaf tip.

Trees in the red oak group (black, northern red, northern pin and others with pointed leaf margins) are highly susceptible and usually die in less than one year. Members of the white oak group (white, bur, swamp white and others with rounded leaf margins) die slowly, often taking several years to succumb to the disease.

The disease is spread by insect vectors (small beetles) and root grafts. Do not injure, prune, or cut oaks during the growing season. It is during this time that insects can carry the disease to fresh wounds on oaks. Apply tree wound paint to any wounds incurred during this time.

Spider Mites

The most common spider mites that attack plants are two spotted spider mite (Tetranychus urticae) and spruce spider mite (Oligonychus ununguis). These tiny arachnids feed by piercing individual plant cells and removing the contents. This causes tiny yellow or white speckles on infested leaves. When a large number of these feeding spots occur near each other, the foliage takes on a yellow or bronzed appearance. Heavily infested plants may be discolored, stunted or even killed.

Control

• Knock spider mites off the plant with a forceful stream of water from a hose.
• Apply insecticidal soap, being sure to cover both the upper and lower leaf surfaces.
• Use a pesticide. Spider mites are not killed by regular insecticides, so be sure the pesticide is reccomended for spiders.

Roses

Everyone loves roses, but they can be a challenge to grow. Hybrid teas, grandifloras and floribudas, although not as easy as landscape roses, can be successfully grown in Wisconsin.

Location. Roses do best in full sun, but can tolerate afternoon shade. Choose a spot with well-drained soil.

Watering. Roses require about 1 inch of water each week. Reduce the chance of disease by applying water only to the soil rather than overhead sprinkling.

Fertilization. Apply a complete fertilizer in early spring (late April) and again when the plants approach their peak flowering (mid to late June). Stop fertilizing by August.

Pests. Learn to recognize the symptoms of insects and diseases. Begin fungicide treatments early on roses with a history of developing diseases.

Garlic

Garlic (Allium sativum) is one of the best known herbs in the world. Garlic varieties are categorized as either hardneck or softneck. Hardneck types produce a woody flower stalk– called a scape – while softneck types do not. Hardneck types typically have four to 12 cloves in a single circle surrounding the stiff stalk (which can’t be braided) and generally do not store well. Softnecks usually produce 10-40 cloves, can be braided, and may be stored for 6-9 months.

Garlic does best in full sun in well-drained soil high in organic matter. Plant garlic in fall, a week or two after the first killing frost. Early the following spring shoots will emerge. Harvest garlic in mid-summer after half of the leaves turn brown. Store as whole bulbs in a cool place.

Watering Plants

Water is critical for plant growth but too little or too much is not good.

Outdoor plants. In-ground plants need an inch of water each week, either from rain or supplemental watering. A thorough weekly watering is much more effective than more frequent light waterings. Be sure to water the entire root zone, not just around the base of the plant (for trees, this is to or beyond the dripline). Place a rain gauge or other container in the watering zone to measure the amount of water applied.

Indoor plants. Many factors determine how often to water your houseplants — temperature, the container, amount of light, etc. Generally, water when the soil surface feels dry to the touch. Provide enough water to thoroughly moisten ALL of the soil in the container – it should run out of the bottom (but not sit in the water).

Cucumber Beetles

Striped and spotted cucumber beetles are a problem on cucumbers and melons mainly because they transmit a bacterial wilt. The first symptom of this disease is a distinct wilting of individual leaves. Eventually, the entire plant wilts and dies. Plants infected with bacterial wilt will not recover. It is therefore important to control the beetles early in the season to prevent infection.

Control

• Cover plants with floating row cover to keep the beetles out (but you must uncover flowering plants for the bees to pollinate).
• Remove diseased plants immediately to prevent the spread to other plants.
• Use insecticides to control the adults, following label directions. Do not apply carbaryl when bees are present.

Dwarf Conifers

Evergreens are a great addition to a landscape, but they often outgrow their space after a number of years. Garden (dwarf) conifers may be the answer for gardeners with limited space. These are slower-growing evergreens that stay smaller in size with minimal pruning. Garden conifers are grouped according to growth rate. Miniatures grow less than 1“ per year; dwarves grow 1-6” per year; intermediates grow 6-12” per year; and large grow over 12” per year.

Cultivated dwarf conifers are available in a variety of colors, including blue, gold, silver, and variegated, in addition to the typical green. They need the same care and maintenance as other conifers — regular watering if rainfall is insufficient and proper mulching.

Broccoli

Broccoli is one of the most nutritious of the cruciferous vegetables. The head we eat is clusters of unopened flower buds.

Set out transplants or direct seed in early spring (and late summer for a fall crop), planting 18” apart. Harvest the central head when buds are developed but still tightly closed; side shoots will then develop.

In addition to traditional green broccoli, you can find purple broccoli; broccoflower which is a cross between broccoli and cauliflower; and broccoli rabe which is more pungent and bitter.

Three species of cabbage worms commonly infest broccoli and its relatives. Control with Bt or other insecticides, or by covering the plants with floating row cover. Aphids may also be a problem. They can be managed by hosing off the plants or with insecticides.

Walnut Toxicity

If you’ve ever tried to grow tomatoes near black walnut, then you know the devastating effect the chemical juglone (produced by black walnuts) can have on certain plants. Juglone causes wilting and yellowing of leaves, and sometimes death in susceptible plants. Its effect is worst at the edge of the tree’s crown, or dripline, but, in general, the toxic zone around a mature walnut tree is within 50-80 feet of its trunk. The following plants are very vulnerable to juglone and should be grown away from a black walnut tree.

The best way to prevent the problem is not to plant a black walnut tree in your yard. If you already have one, grow sensitive plants well away from walnut trees.

Eastern Tent Caterpillar

Conspicuous white masses in the forks of tree limbs in early spring are the tents of the native eastern tent caterpillar, Malacosoma americanum. A colony of hairy caterpillars lives in the tent, coming out to feed at night. Trees most commonly affected are fruit trees, such as apple, cherry, flowering
crabapple, plum, and chokecherry, but the caterpillars may also defoliate other hardwood trees.

Infestations rarely kill trees – the damage is primarily cosmetic. Even if completely defoliated, most trees will produce new leaves within two or three weeks.

Control

• Remove and destroy eggs masses in winter.
• Remove small tents by hand (wearing gloves).
• Remove larger webs with a broom or stick.
• Use insecticides only for caterpillars less than one inch in length; do NOT use products that can kill bees if the tree is flowering.

Oregano

An essential flavoring in Italian cuisine, this herb is also used in Spanish, North African and Greek cooking. There are several different species of oregano. In Wisconsin many species are not hardy and are better grown as annuals or pot plants. Greek oregano (Origanum heracleotium or O. vulgare subsp. hirtum) is more flavorful but less hardy than European or common oregano (O. vulgare). The related sweet marjoram, O. majorana, is not winter hardy here and tastes different than oregano.

Greek oregano, the most common type available, grows low to the ground, rooting as it grows outward. It is a vigorous spreader, but not invasive. Grow oregano from seed or purchased plants in well-drained soil with full sun. Harvest a few sprigs at a time after the shoots are 4-5” tall. To dry, tie in bunches and hang in a warm, dry shaded place until crisp. Then strip the leaves from the stems and store in an airtight container.

Onions

Onions are biennial plants grown as annuals for their edible bulb. This is a cool season crop that can tolerate some frost. Although many varieties are available, choose long or intermediate day types for our growing conditions.

Onions are grown from transplants or sets (small bulbs). Both should be planted in late April or early May. Planting close together results in earlier, smaller bulbs. Plants spaced farther apart will allow bulbs to grow bigger and mature later. Onions have shallow roots, so cultivate carefully when weeding. Reduce watering 2-3 weeks before harvest.

Dig onions for storage when 50-80% of the tops have fallen over. Avoid bruising that may cause rotting. Cure bulbs at 85-90°F for one week before storing at a cool temperature (32-40°F).

Fire Blight

Fire blight is a destructive bacterial disease (caused by Erwinia amylovora) that kills blossoms, shoots, limbs, and, sometimes, entire trees. It affects many plants including apple, pear, crabapple, hawthorn, cotoneaster, mountainash, and spirea.

The most noticeable symptoms of this disease are browning of all the leaves on a branch, and wilting of the affected branch to form a “shepherd’s crook.” The blighted blossoms and leaves tend to stay on the tree instead of falling, giving the appearance of being scorched in a fire.

Control

• Choose plants with resistance to fire blight and avoid applying high nitrogen fertilizer.
• Prune diseased branches when dormant and dry, cutting 6-8” below the visible symptoms. Disinfect pruning tools by dipping them for at least 30 seconds in 10% bleach solution.
• Treat with copper sulfate before buds open.

Dandelion

This common yellow flower seems to spring up overnight. Dandelion is a short-lived perennial that is excellent at spreading its numerous seeds. It can also reproduce from pieces of taproot. Dandelions are generally only a problem in thin, slow growing lawns that cannot out-compete the weeds.

Control

• Prevent dandelions (and other weeds) from getting started by creating a thick, healthy lawn with correct mowing, fertilizing and watering.
• If you only have a few dandelions, use a digging stick or other garden tool to remove the dandelion and most of the root.
• Spot treat with an herbicide individual plants in lawns instead of making broadcast treatments.Herbicide applications made in late summer and early fall are most effective.

Geraniums

Geraniums have long been popular decorative plants for indoor and outdoor use. These are actually members of the genus Pelargonium and are usually grown as annuals since they do not overwinter outdoors in Wisconsin. (Members of the genus Geranium, called “hardy geraniums” or cranesbills, are winter hardy garden perennials). There are many forms, types and species available, with great variation in leaf and growth characteristics, and with red, pink, orange or white flowers.

When purchasing geranium plants, look for sturdy plants with good leaf color and a bushy habit instead of a single, top-heavytem. Plant outdoors after all danger of frost is past. Geraniums best with 6-8 hours of sunlight per day and can be grown in the ground or in containers. Keep the soil evenly moist but not wet.

Lettuce

Lettuce is one of the oldest known vegetables, with hundreds of varieties to choose from in a wide range of sizes, colors, textures and tastes.

Lettuce is one of the easiest, fastest and earliest crops for the home gardener. It doesn’t require a lot of space and does best in cool weather – spring and fall in Wisconsin. Plant seeds in the garden as early as 4 to 6 weeks before the average date of last frost in well-worked soil with good drainage and moisture retention. For a fall crop plant seeds in late August and September. Sow seeds ¼ inch deep and space rows 12 inches apart. Thin to 4-6” apart when the seedlings are large enough to handle.

As lettuce grows you can selectively harvest outer leaves, leaving the inner leaves to develop, or harvest the entire plant at maturity by cutting it off at ground level.