Rosie Lerner

Rosie Lerner's website
Extension Consumer Horticulture Specialist
Purdue University
Department of Horticulture and Landscape Architecture
625 Agriculture Mall Drive
West Lafayette IN 47907-2010

Voice: 765-494-1296
Fax: 765-494-0391

705 articles by this author

Article List

What’s killing the oak trees?


Q. In 22 years I’ve had more than a dozen oaks die because of a grub or larvae. Symptoms: First the leaves die and turn brown at the top of the tree. It slowly spreads down the tree until all the leaves are brown and have fallen off. Then the bark begins to peel away from the trunk, and then it falls off pieces at a time. You can see where it cuts off the […]

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December Garden Calendar


HOME (Indoor plants and activities) Check houseplant leaves for brown, dry edges, which indicates too little relative humidity in the house. Increase humidity by running a humidifier, grouping plants or using pebble trays. Extend the lives of holiday plants such as poinsettias and Christmas cactus by placing them in a cool, brightly lit area that is free from warm or cold drafts. Houseplants may not receive adequate light because days are short and gloomy. Move […]


Thankful for Cranberries


The cranberry plant is native to large portions of the northeastern United States as well as the West Coast states and portions of Canada. Cranberry production requires a rather unique acid bog habitat, which restricts its commercial production to just a few states. Wisconsin, Massachusetts, New Jersey, Oregon, and Washington are the leading producers in the US. The ideal soil pH is 4.0-5.5, quite acidic compared to other horticultural crops. A large supply of fresh […]


Honeyvine – a native plant that can be both friend and foe.


Q: This vine has perennially volunteered in my garden for a few years now. I let it grow because it seemed to please the butterflies, and the small white flowers smelled nice. At present it has grown chartreuse seed pods. Can you tell me what this vine is? Is it something I should destroy? – W.B. A: Ah, beauty and function are in the eye of the beholder. I believe your plant is what is […]

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November Garden Calendar


HOME (Indoor plants and activities) As houseplant growth slows, apply less fertilizer and water. If plants are dropping many leaves, move them closer to sunny exposures, such as west- and south-facing windows. Artificial lights may be needed to supplement particularly dark rooms. Pot spring-flowering bulbs with tips exposed to force into bloom indoors. Moisten soil and refrigerate 10 to 13 weeks. Transfer to a cool, sunny location, and allow an additional three to four weeks […]


Cut Back Perennials Now or Later?


Gardeners often ask, “When is the best time to cut back the dead tops of herbaceous perennials (stems die back to the ground each year)? Should we cut them in fall as the tops fade? Or wait until spring, just before new growth begins?” The answers depend, in part, on the specific plant and whether disease or insect pests are a factor. For most healthy plants, leaving plant tops over winter is fine and, in […]


Mystery plant likely a flowering quince


Q: Can you help me identify this shrub that flowered this spring? We’ve lived on this property for over 10 years but have never noticed it because it is on a part of the property that is not mowed. I only noticed it because of the bright red flowers. – T.G., Noble County A: This looks to be one of the flowering quince species, most likely the common flowering quince Chaenomeles speciosa. Although the plant […]

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Fall Leaves Are Treasure, Not Trash


The hot dry weather experienced throughout much of Indiana in late summer is bringing an early leaf drop to many landscape plants. But even under the best weather conditions, the shorter, cooler days of autumn signal deciduous plants to begin their color change and eventual leaf drop. For some, this marvel is overshadowed by the chores of raking and disposing of leaves. What’s needed here is an attitude adjustment! Autumn leaves don’t have to become […]


October Garden Calendar


HOME (Indoor plants and activities) Keep poinsettia in complete darkness for 15 hours each day — for example, between 5 p.m. and 8 a.m. — for eight to 10 weeks until red bracts begin to show. Pot spring-flowering bulbs to force into bloom indoors. Moisten soil and refrigerate 10 to 13 weeks. Transfer to a cool, sunny location, and allow an additional three to four weeks for blooming. Houseplants, especially those grown outdoors during the […]


Don’t let sap-sucking squash bugs get old


Q: We have been battling squash bugs for years. This year we went to preventive measures. Well, they are back. I now need to know what can we do to apply to kill them on contact. We are totally organic here. – T.H., Bremen, Indiana A: Squash bugs can be a persistent pest on all of the cucurbits, but especially on squash and pumpkins. This pest overwinters as adults in crop residue or nearby weeds, then fly to […]