Problems and Diseases With Regal Geraniums

  • tải xuống (3) Regal geraniums are a group of plants referred to as Pelagonium domesticum. Regal geraniums are also called Martha Washington geraniums. The plants grow to a mature height of 1 to 4 feet and bloom with single or double flowers clusters in solid or mixed colors. The scented foliage is rounded, lobed or toothed. Regal geraniums are hardy in U.S. Department of Agriculture plant hardiness zones 10 and 11 and are susceptible to a number of problems and diseases common to pelargonium varieties.

Bacterial Blight

  • Bacterial blight is a common problem with geraniums, including regal geraniums, according to University of California’s Integrated Pest Management Program. The bacterial disease is caused by Erwinia, Pseudomonas or Xanthomonas spp. The disease is characterized by the rotting and browning of infected plant tissues accompanied by an unpleasant odor. The deterioration is most evident near the soil line. Infected plants are also stunted. As disease progresses, dead plant tissue falls out giving the plants a jagged look. Management includes using plants from reliable sources. Plant in well-drained soil and do not used overhead irrigation.

Crown Gall

  • Regal geraniums, and other pelargonium, may be affected by crown gall. The bacterial disease is caused by Agrobacterium tumefaciens and is characterized with the appearance of distorted growths on the roots just below the soil line. In severe cases, the galls also appear on the limbs, trunks and foliage. Infected plants lose vigor and become susceptible to other diseases. Use clean pruning tools, good quality plants, and avoid unnecessarily injuring plants to prevent crown gall. Chemical control options includes the use of Agrobacterium tumefaciens K-84, a biological agent.

Deficiency or Excess of Water

  • Too much or too little water is cited as a common problem with pelargonium varieties. When plants get too little water, it leads to wilting and discolored foliage with premature leaf drop. Too much water also causes poor plant growth and is especially damaging to the roots because a majority of bacteria and fungi thrive in excessively moist soil. Management includes planting in well-drained soil and watering according to plant requirements. Avoid overhead irrigation and drip irrigation methods.

How to Identify Wild Geraniums

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The wild geranium (Geranium maculatum L.) is a common flowering perennial plant that is native to the United States. Also known as spotted geranium and cranesbill, it grows in 35 states, including all those of the eastern half of the country with the exception of Florida. Wild geranium is a showy plant, with large flowers and easily identifiable leaves. This makes differentiating it from other wild flowers a simple process.

Difficulty:
Easy

Instructions

Things You’ll Need
  • Measuring tape
    1. Look for a plant with pink or lavender five-petal flowers 1.5 inches in width.
    2. Hold the measuring tape against the plant and measure the height. Wild geraniums stand between 1 and 3 feet tall.
    3. Look at the leaves and count the lobes. Wild geraniums have five-lobe leaves that are pointy and resemble palm leaves. Measure the leaves. They are usually between 2 and 5 inches long.
    4. Pull your finger across the leaf surface. Wild geranium leaves have fine white hairs that you should feel with your fingers.
    5. Examine the flower stem, just below the blossom. You should see thick hairs and three-lobe leaves just below the flower. If the plant meets all these criteria, it is a wild geranium.

Facts of Wild Geraniums

000 Many people hearing the word "geranium," think of the common window box and bedding varieties. These are actually pelargoniums. While they are part of the Geraniaceae—or Geranium—family, they are not geraniums. True geraniums grow wild in many parts of the world, from mountainous regions to the tropics.

Appearance

  • Geraniums are usually branched plants with lobed or dissected leaves.The flowers, which can be white, rose, mauve, purple or shades of pink, are most often simple, with five petals each. The blooms sometimes have veins in a contrasting color. A few species, like the Eurasian Geranium platypetalum, feature double flowers.

Names

  • Wild geranium species have acquired many nicknames, the most prominent of which is "cranesbill." The nickname is derived from the shape of the seedhead, which is bulbous on one end and tapers to a point on the other, resembling the beaked head of a crane.

American Natives

  • Some geranium species are native to North America. Among them is Geranium maculatum, or spotted cranesbill, which has pink flowers. Geranium robertianum, also called "Herb Robert," is found in eastern and central North America. It produces small pink flowers, fern-like leaves and distinctive red stems.

Family Members

  • Wild geranium species are the parents of many well-known hardy geranium varieties. Bevan’s Variety, for example, is a cultivar of the European Geranium macrorhizum, which features pink flowers and apple-scented leaves. Geranium maculatum is a parent of the popular Johnson’s Blue hardy geranium.

How to Preserve Geraniums Through the Winter

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Each spring, many homeowners decorate their porches and flower beds with colorful geraniums. These flowers are an investment and it’s disappointing to have to send them to the compost pile each fall. Fortunately, you don’t have to. You can overwinter your geraniums and bring them back each spring fully restored — giving you a head start on your spring planting and stretching your flower budget.

Difficulty:
Moderately Easy

Instructions

Active Storage

  1. Cut geraniums back to their original size. Inspect them for signs of bugs or disease.
  2. Dig up healthy geraniums from the garden before the first frost. Replant them in containers.
  3. Bring the potted plants indoors and place them in a sunny and bright location. If you do not have a window they can sit near, provide them with artificial light for at least a few hours each day. Place the light about a foot away from the plant.
  4. Water your geraniums occasionally, but not too much. Too much water will cause root rot. Geraniums are much more likely to thrive in dry conditions than wet ones.

Dormant Storage

  1. Store your geraniums in a dormant state by digging up the whole plant and shaking the soil gently from the roots.
  2. Place the plants in open paper bags or hang them upside down in a cool area, such as an attic or garage. Store them where the temperature is 45 and 50 degrees.
  3. Take the plants out of the bags or down from the rafters two or three times during the winter. Soak the roots in water for a couple of hours.
  4. Inspect the stems when you soak the roots. The leaves will die and fall off, but the stems should stay firm and solid.
  5. Repot healthy geraniums in late March or early April. Water the plants thoroughly and place them in a sunny window to encourage new growth. Replant your geraniums outside or set your containers outside once the danger of frost has passed.

Propagation of Martha Washington Geraniums

Martha

The Martha Washington geranium, or Pelargonium domesticum, blooms differently from other flowers in the geranium family. The Washington variety tends to bloom strong and bright in the early spring and summer, but as the heat increases and summer wears on, it will fade away. This species of geranium can’t stand hot sun or high humidity, so it’s grown as a spring or fall plant or a houseplant only. Like all geraniums, the best way to propagate the Martha Washington is by taking cuttings after bloom.

Difficulty:
Moderately Easy

Instructions

Things You’ll Need
  • Pruning scissors or shears
  • Peat moss
  • Perlite
  • Planting pots
  • Plastic covering
  1. Gently separate the shoots of the plant so you can identify the older shoots. Best cuttings are made from shoots with multiple nodes or joints. Make your cuttings in early autumn–in late August or early September in most areas.
  2. Cut a shoot 4 to 6 inches long just below a node. Take multiple pieces if you intend to propagate more than one geranium. Remove less than half of the shoots from the original geranium to avoid damaging it.
  3. Set your cuttings into a potting mix made of equal parts peat moss and perlite. Insert the cutting only deep enough to ensure that it will stand upright. You can place multiple cuttings into one pot.
  4. Cover the cuttings with protective plastic or polyethylene. Set the cuttings in bright, indirect sunlight. The plants should take root within five weeks.
  5. Plant each rooted cutting in its own potting container with regular potting soil once each has formed its own roots. Water and feed the cutting just like a regular geranium.
  6. Pinch back the growing tips in early January, removing the top half of each shoot. Repeat pinching again in early February. These pinchings, like pruning a tree, will encourage thicker and healthy growth as bloom time approaches.

Tips & Warnings

  • Do not pinch the geraniums again after February, or you will set back flowering by at least one month.