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September 2011 Gardening Q&A
Wild onions in the daylily bed
 by B. Rosie Lerner
Purdue Consumer Horticulturist
Controlling weed may require relocating lilies for awhile
Q: I have raised daylilies for several years. I am having a major problem with wild onions in my beds. I have tried glyphosate on a paper towel with rubber gloves and wiping all the onions I can see. Seems to be getting worse rather than better. I also cut off the seed heads so as not to reseed each season. Any suggestions? — J. Kaiser, Orleans, Ind.
A: Wild onion is difficult to control in any situation; their narrow waxy leaves repel herbicide sprays such that very little chemical gets into the plant. This perennial weed is particularly troublesome when growing amongst herbaceous perennials, since there is no herbicide that can be applied that would control the onion without also damaging the daylilies. In fact, it would do much more harm to the daylilies than the onions!
Hand pulling the onions does little good, as the underground bulbs will sprout new foliage. Hand digging the bulbs is likely the only solution but may also damage the daylily roots. Cutting the onion foliage just before spot applying glyphosate may improve control.
If the bed is badly infested, it might be wise to dig up and relocate the daylilies either permanently or temporarily until the onions can be removed or controlled. Be sure to clean the daylily roots and soil from onion bulbs before replanting in the new location.
 Q: Perry County has catalpa trees with long pods; however, I have a tree that has most features of the catalpa with the exception of nut-like pods. Can you please identify this tree? The leaves are about 6-8 inches wide; nuts are about 1 inch and very sticky when cracked. Would they be dangerous for our cattle to eat? — Violet Brown, Tell City, Ind.
A: This tree is known as the Royal Paulownia or Empress Tree, Paulownia tomentosa and is NOT related to Catalpa. The fruits are capsules that open to release many winged seeds in the fall. In northern Indiana, Paulownia dies back to the ground each winter and resprouts the following spring with rather impressively dramatic annual foliage growth. The tree may form what appear to be flower buds, but it usually does not flower, and I have never seen it fruit this far north. I have seen it in full bloom while traveling elsewhere and it is rather pretty in flower. It can be a messy nuisance with dropped flowers and seeds and is considered invasive in many areas where it is hardy.
None of my poisonous plant references list this specie and some articles mention using the foliage as livestock fodder. I don’t imagine that the empty fruit capsules will be of much value.
Q: The property I moved to a year ago has a full-grown peach tree in the front yard. It is full of little baby peaches, but they are mostly all emitting a little hardened clear gel-like material. I can see from some branches that at one time there were diseased darkened spots where the limbs meet the trunk. Do you have any idea what it needs so I can salvage it and get healthy fruit? — Connie Mitchell, via e-mail
A: This sounds like Oriental fruit moth, a primary pest of peach that will also infest plum, apricot, nectarine, cherry, apple and pear. This pest has two or more generations of young during the growing season. The early generation larvae enter young twigs and may also feed on and enter the side of the fruit. If the fruit remains on the tree, a clear, gummy exudate will ooze from the wound, eventually turning black. Additional generations of larvae are more likely to enter nearly ripe fruit from the stem end, tunneling and feeding down to the stony pit.
The pest overwinters in litter around the tree as well as on the bark; immediate removal of infested fruits and fall clean up of leaves and dropped fruit can reduce next year’s woes. There has been some success of mating disruption with pheromone products as well as parasitic braconid wasps. Multipurpose fruit spray or an insecticide containing esfenvalerate or carbaryl labeled for home orchard use can provide effective control of this pest, but timing of the sprays is critical, beginning at petal fall (when 75 percent of the petals have dropped) and an additional two-three applications every 10-14 days.
For more information on controlling pests in the home orchard, have a look at Purdue Extension Publication ID-146 Managing Pests in Home Fruit Plantings, http://extension.entm.purdue.edu/publications/ID-146.pdf.
The darkened spots on the trunk could indicate a canker disease or possibly insect borer damage, but I am not able to diagnose just from that description. Consider taking digital images of the injury, both close up and overall tree to submit to the Purdue Plant & Pest Diagnostic Lab, www.ppdl.purdue.edu.
Q: I planted a Stanley plum tree in the spring of 2005. I chose this tree because it is considered a self-pollinator. The tree is well established and flowers bountifully. Then when the fruit is about the size of a large grape, it drops every single plum off the tree. There is no sign of a pest problem. I have seen other readers ask about their trees dropping some fruit, but my tree drops every single fruit, not even leaving me one plum to enjoy. Do you have any thoughts on what would make the tree drop off every fruit for the last 3 or 4 years? Any suggestions would be greatly appreciated. — Jennifer Gibson, Dubois County
A: This certainly sounds like inadequate pollination (or, more correctly termed, fertilization of the ovules). Stanley is supposed to be self-fruitful, but even those cultivars benefit from cross-pollination. It would not hurt to plant another compatible cultivar, such as Damson or Green Gage.
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