OCTOBER
2002

 

 

 

By
Beverly Shaw
 
Advanced
Master Gardener
Purdue University

 

 

 

 

 

10-3-02

Question and Answer

Q.  We need your expert help concerning our Stanley plum tree. We planted the tree four years ago. The catalog said it is self-pollinating. One year we had two plums. Another year we had none. This year, I found 10 on the ground. All were green and small. What is wrong? The closest other tree is an old persimmon, and it is always loaded with fruit. Do we need fertilizer? If yes, what kind? Did we plant the tree too deep? -- Theresa Gilstrap, Orleans, Ohio

A.  At four years of age, your tree is not expected to produce a full crop, so the number of fruits produced is not surprising. The fruit drop can occur for several reasons. Many fruit crops did not do well this year because of late frosts and heavy rains. These are less-than-desirable conditions for pollination.

An insect called plum curculio could also cause the immature fruit drop. If it happens again, inspect the fallen fruit for black, crescent-shaped scars.

Stanley plums are self-fruitful but the more pollen the better! If space allows, you might choose to plant another nearby.

Keep the plant healthy by applying 1 pound of a 12-12-12 fertilizer (or equivalent) for each year of tree age or each inch of trunk diameter, up to a maximum application of 8 to 12 pounds per tree. Apply in early spring. Where trees are making adequate growth and fruiting regularly, no fertilizer application may be required.

Q.  We have an old patch of Redchief strawberries, which we have been babying for years. We do get lots of catalogs but cannot find one that sells Redchiefs. Can you find someplace that sells them? -- Robert Trump, Plymouth, Ind.

A.  Redchief is the old, standard variety for the commercial grower, and it is still considered a good, all-around berry. The Indiana Berry & Plant Co. reports its hardiness and resistance to Red Stele makes it a consistent producer of medium to large, firm fruit that is excellent for freezing. Although it is still widely planted, it has been steadily replaced by Honeoye and Jewel for commercial planting.

Redchief is available from Mellinger’s at http://www.mellingers.com or 1-800-321-7444 and also from the Indiana Berry & Plant Co. at 1-800-295-2226 or http://www.inberry.com.

Q.  My hydrangea bush almost tripled in size this summer. I cut some of the top back as it was covering some of the lower flowers. They are beautiful colors of green, pink and blue. I want to keep this plant healthy. It's almost 4 feet tall. How do I thin it, and is there any way to divide it into smaller sections, like a hosta? -- Joe Holmquest, Winamac, Ind.

A.  Your hydrangea looks beautiful in the photograph you sent. While it appears healthy now, hydrangeas are heavy feeders, so watch for yellowing leaves during the summer, indicating a need for fertilizer.

Hydrangeas do not lend themselves to division like hostas. Instead, they are most often propagated by cuttings. To do this, take a 5- to 6-inch cutting, preferably from a branch that did not flower this year. Remove the lower leaves of the bottom two leaf nodes. Dip the ends of the cuttings in rooting hormone, and insert into damp vermiculite or sterile medium. Water them well, and allow to drain. The soil should be moist but not soggy. Cover them with plastic but keep the plastic from touching the leaves by adding stakes. Place the cuttings in bright light but avoid direct sun. Do not overwater. When roots form in 2-3 weeks, transplant the cuttings into potting soil, and keep them indoors until spring.

Q.  I have seen many hydrangeas blooming abundantly in Plymouth. These bushes have mophead blue or pink flowers that are like my 'Nikko Blue' hydrangeas. What type of hydrangeas are these, and do you know where I could purchase them? I understand hydrangeas bloom on previous year's wood and that our zone is really too cold for hydrangeas. So what's the deal with these bushes? -- Lynn Beauchamp, Plymouth, Ind.

A.  The bigleaf hydrangea, H. macrophylla, is the plant with huge flower clusters whose color can be pink or blue, depending on the soil pH (blue flowers in acidic soil, pink flowers in alkaline soil). Southern Indiana gardeners have had some luck with this plant, but, unfortunately for most Indiana gardeners, this particular species does not flower reliably in our area. It normally blooms on previous year's growth, and, because it breaks dormancy very early, its flower buds are most often killed in USDA hardiness zone 5. The vegetative buds often survive, or new shoots sprout from the roots if killed back to the ground, forming a tidy, little foliage plant, but, alas, no blooms.

Your 'Nikko Blue' hydrangea is a cultivar of the mophead or lacecaps that you're seeing. Larger blooms can be encouraged by fertilizing regularly, providing full morning sun and removing some of the flowers when they emerge, thereby putting more energy into the production of the remaining flowers.

There is plenty of information available online at http://www.hydrangeashydrangeas.com or in an article by Purdue Extension Consumer Horticulturist Rosie Lerner at http://www.hort.purdue.edu/ext/hydrangea.html.

Growers are working on a reliably blooming cultivar for Indiana. A new cultivar called 'Endless Summer' originates from a planting in Minnesota, which appears to bloom reliably and repeatedly on current season's growth. 'Endless Summer' is scheduled for release in spring 2004 by Bailey's Nurseries in Minnesota and may be worth the wait.

 

Contact: B. Rosie Lerner
Editor: Olivia Maddox,