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Pear Slug Pear Slug
Ron Smith answers questions about flowers, trees, gardens and shrubs.

By Ron Smith, Horticulturist

NDSU Extension Service

Q: I bought my jade plants a couple of months ago here in Alabama. I'm noticing that some of the leaves are taking on an abnormal clubfoot shape at the tip. It is almost a trilobite look. Are you familiar with this? I thought that it could be from underwatering. However, I have underwatered jades before and never had these symptoms. I'm beginning to worry. Also, it seems that my jades have a rough time in my house during the cold months. One winter, I lost my favorite plant when it sort of melted at the base of the stem/trunk. My jades seem to have a significant yellowing and leaf drop the week they come inside. This seems to last until the week they get to go outside again. Is this normal? I must be doing something wrong. Do you have any suggestions on indoor jade care? Thank you so much for allowing me to take up some of your time. (email reference)

A: There are a couple of gaps that many people overlook in caring for their jade as a houseplant. Hot or cold drafts could cause problems. Leaking natural gas or some other indoor air pollutant that cannot be picked up by the human sense of smell could be a problem. Two of the major problems for any houseplants are underlighting or overwatering. It could be something in the water, such as a chemical, or the water is too cold. Try watering with distilled water a few times to see if the plants improve. Plants kept in a container that has bad drainage will develop anomalous forms and, as the root zone becomes more anaerobic, leaf drop begins. When a plant is moved from indoors to outdoors or the other way around, there often is the reaction you described.

Q: We live in north-central Minnesota. In the fall of 2010, I purchased a hopa crab tree from our local garden store. It leafed out fine this spring, but it never produced blossoms. Is this normal or was the tree possibly mismarked and isn't a flowering crab? (email reference)

A: It could be that this is an establishment phenomenon. Wait and see what happens in 2012. Hopa crab should be perfectly hardy in your part of the state unless it is planted in a microclimate situation that would impact flowering. The tree may need another year of maturity to produce flowers. Some flowers should show this spring.

Q: I moved into a house about two months ago. There are several hydrangea bushes in our backyard that have dead blooms and green leaves on the top of the bushes. The bottoms of the bushes look very dry and dead. I cut a couple of the bottom branches off and saw that they were green inside. How do I revive them? I don't know much about gardening, and this is the first time I've had a yard. I would love to have beautiful, healthy hydrangeas. From doing a little research online, they look like mop head hydrangeas. I appreciate any advice you could offer. (Charleston, S.C.)

A: Your hydrangeas will be OK. Cut the plants back to about 6-inch nubs. When spring arrives in your part of the country, new growth will emerge from the base and produce new blooms for you. If the plants are the type that will produce blooms on new growth only, they will be covered with flowers. If they are the type that blooms on the previous season’s growth, only a few flowers will show up. Some of the newer cultivars will do their blooming on new and previous season’s growth. In that case, you will have more flowers than you can count.

Q: My slug problem consists of these slimy creatures making their way into my garage. My garage is attached to my home that was built off the ground. They are making their way in the garage from under my home. When I see the slugs, I pour salt on them and it seems they die an excruciating death. Am I doing the correct thing? What else should I do? Where are they coming from and why are they staying? Sorry for asking so many questions and the lengthy email. (email reference)

A: Slugs like a combination of cover and continuous moisture. Where these conditions exist on your property is where they are originating. There are a number of options for controlling these slimy pests. Your salt treatment is 100 percent effective when they cross that barrier. Another idea is to use hydrated lime, which also will dehydrate the slugs. You could use diatomaceous earth, which is ground-up diatoms from reefs. It will lacerate their soft tissue, causing fluid loss and eventually killing them from dehydration. There are poisons and slug motels where the slugs check in but never check out. Slug motels are good for minor slug control. From your description, you'd probably go bankrupt collecting all the motels from your property. If your own attempts are not effective to your satisfaction, then I'd suggest getting in touch with a professional pest control company to do the job. Most will guarantee their results.

Q: I have a flowering crab tree in my yard. For the first time in 25 years, gray squirrels are eating the bark. I do not want to lose this tree because I get so much shade from it in the summer. However, I also do not want to kill any squirrels. Is there anything I can do to keep this from happening? (email reference)

A: Be sure access to the tree is not from adjacent trees or a roof. Then, cut as many branches as possible from the bottom to keep access to the tree by jumping somewhat limited. I’ve seen squirrels jump 4 feet, so don’t be too shy about cutting some of the lower branches off. Make a mushroom-shaped barrier that is the same type used on ships to keep rats from getting on board. You can try repellents such as fox urine. It comes in a granular form that you can sprinkle under your tree. This is said to scare them off. Some success has been documented with grease or Vaseline mixed with a hot pepper liquid (be sure to protect your hands) and smeared on the branches and trunk of the tree. Finally, there is the Hav-A-Heart trap. Bait it with peanut butter and crackers. You then can transport them to the country if euthanizing is not an option for you. If you visit some local hardware stores, you will find a selection of ideas, equipment or supplies that can work to protect your tree from further squirrel damage. Q: I just happened across you website and am very impressed. I hope you are happy to answer questions from Australia. I have small slugs on my cherry trees. Can you give advice on what to do to eradicate this problem? Thanks. (email reference)

A: I think your problem is pear slugs. The name is a total misnomer because these are not slugs and have nothing to do with pear trees. This is an indiscriminate feeder that skeletonizes the foliage and is the larval stage of a sawfly. Left unchecked, they can denude a tree or shrub in a short time. You need to get it under control with whatever insecticides are legal to use in your country.

Q: I followed the instructions for getting my Christmas cactus to flower. It looked lovely but only had 10 blooms. All the other buds fell off. Every branch had a bud on it. Any ideas as to what the problem could be? I gave it Miracle-Gro once and did not overwater. (email reference)

A: There is no rational explanation for this inconsistency that I am aware of. We like to blame ourselves for what we did or didn’t do even though there is no basis for accepting the blame. All I can advise you to do is be consistent with the location and watering regime. Keep the plant away from heating or air conditioning vents. Keep in mind that the plant needs a cooling period and reduced water input to bloom.

To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or email

NDSU Agriculture Communication – Dec. 21, 2011

Source:Ron Smith, (701) 231-7971,
Editor:Rich Mattern, (701) 231-6136,
Prairie Fare: Prairie Fare: De-stress with Gardening  (2019-05-23)  According to researchers, gardening can be beneficial for mental, physical and social health.  FULL STORY
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