NOVEMBER
2002

 

 

 

By
Beverly Shaw
 
Advanced
Master Gardener
Purdue University

 

 

 

 

 

11-07-02

Question and Answer

Q. I am a resident of Orange County, just outside of Paoli. I recently noticed that my red horse chestnut tree, which had previously lost all of its leaves due to drought, has sprouted several red flowers. Some leaves are coming out and MANY buds are swelling. Many buds are not swelling, and I hope they stay that way.

The drought tricked the tree into early dormancy, and now the recent rains have awakened the tree into thinking it is springtime. The problem is that frost and winter are just around the corner. Will my prized red horse chestnut tree be killed by winter's cold? Should or can anything be done to re-establish dormancy?

Many other gardeners and landscapers may be facing similar problems due to the drought. -- Curtis Thill, Paoli, Ind.

A. Your tree has been tricked! It's fairly common for some plants to jump the gun and bloom. in the fall if the weather is unusual. Last year, many forsythia and magnolias bloomed in the fall. Unfortunately, the buds that bloom prematurely will not be available to bloom next spring. Fortunately, usually only some percentage of the buds burst early, so some flowering may still take place next year. And this doesn't usually damage the plant long-term. It only reduces next spring's flowering. There's little you can do to change the situation.

Q. My neighbor gave me a yucca plant the year before last. It lived but didn't bloom. And guess what? This year, it bloomed and I love it! The yucca plant is now full of seed pods, and I am wondering if it is possible to plant them and get LOTS of yuccas. If so, how do we do this? Indoors? -- June DeSpain

A. Remove the dry seeds from the pod, and store them dry at room temperature until you're ready to plant them. Germination can be aided by soaking the seeds in water for 24 hours. Plant the seeds outdoors in spring in a sunny area with good drainage. If you'd like to start them indoors, choose a flat with drainage holes, fill it with potting mix and plant the seeds. Germination takes place slowly, and it will take 4-5 years before the new plants are old enough to bloom. Yuccas require full sun and sharply drained soil.

Q. We would like to transplant some rhubarb and were wondering when is the best time, what is the best soil type to move it to and what is the proper way to do it? -- Jody Huhn and Kerry Belstra, DeMotte, Ind.

A. You can propagate your own plants by dividing the crown of a healthy plant, preferably in early spring before new growth begins. Leave as many roots as possible with each division. Rhubarb divided in late fall should be protected with a winter mulch of straw or similar material after several hard frosts. Place the crowns 3 feet apart in rows that are spaced 5-6 feet. Use shallow furrows so that crowns will be only 2 inches below the surface. Space the crowns so that each plant will have 12-15 square feet. Do not set the crowns in direct contact with commercial fertilizer.

A fertile, well-drained, sandy loam is best for rhubarb. A well-drained soil will diminish the chances of crown rot. Liberal applications of fertilizer should be included. Broadcast fertilizer over the entire bed surface. A 1:1:1 ratio, such as 12-12-12, should be used at the rate of about 3-4 pounds per 100 square feet.

Plants should be divided and reset every 8-10 years. Use a sharp spade to divide the crown, leaving three or four buds undisturbed in the old location. Old plants that become thick only produce inferior, slender stems.

Q. I have 15-20 Washington Hawthorn trees that are diseased and need help. They are about 20-22 years old. They look healthy with heavy foliage and bloom. The fruit develops well with many berries. While the fruit is still green, each berry develops many spines, turns brown and falls off the tree. No berries for the birds. Any help will be appreciated. -- Preston R. Acres, Elizabethtown, Ind.

A. Your trees are infected with cedar-quince rust, a common fungal disease. Cedar-quince rust affects quince (Chaenomeles), serviceberry (Amelanchier), hawthorn (Crataegus), mountain ash (Sorbus) and many other plants in the rose family and can cause a great amount of damage to the fruits, twigs and thorns of susceptible plants.

The fungus requires two different tree species to complete its lifecycle. On the first host, juniper or red cedar, the fungus infects leaves and soft shoots, becomes perennial in the living bark and causes swellings that girdle twigs and small branches. In damp weather, galls are covered with masses of gelatinous, orange-to-brown spore horns. As they age, they look like orange slime deposits.

The next phase of the lifecycle takes place on the alternate hosts (hawthorn, quince, apple and crabapple). The most common symptom is on hawthorn. Fruits become uniformly covered with small pinkish-white structures, then dry out. Twigs become enlarged and woody.

The rust fungi are dependent upon both hosts for survival. Removal of one or the other breaks the lifecycle of the fungus, thus preventing disease. Unfortunately, the spores can travel a distance of at least one-quarter mile between eastern red cedar and junipers and alternate hosts. Some sources say they can travel a handful of miles! This makes removal impractical. Whenever possible, at least avoid planting the two different host types right next to each other. Remove any orange gelatinous areas from your cedar or juniper twigs during the growing season, and prune out any galls or cankers they may have in late winter. However, even if you are successful in removing all galls, infectious spores can be blown in from other trees.

The best method of avoiding cedar rust diseases is to use resistant plants when installing new trees. However, your Washington hawthorns are susceptible to cedar rusts.

Fungicides are preventive and must be applied several times during early spring to maintain a protective coating on developing leaves, twigs and fruit. When spring weather is dry, fungicide applications may not be required. Read and follow label instructions regarding amounts of fungicide, method of application and safety precautions.

Registered fungicides for rust control are subject to change. Your case sounds like it will require some measure of chemical control. For current control recommendations, consult the Purdue Extension office in your county or Purdue University's Plant and Pest Diagnostic Laboratory, 1155 LSPS, Purdue University, West Lafayette, IN 47907, or call (765) 494-7071.

Pictures of this highly photogenic condition can be found at http://ohioline.osu.edu/hyg-fact/3000/3055.html.

 

Contact: B. Rosie Lerner
Editor: Olivia Maddox,