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Mammillaria pilcayensis

Hortiscope: Plant light may cure flowering cactus' odd growth

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Q: I have a Norway maple with longitudinal cracks from the ground up. I know this is normal for this species, but my question concerns structural integrity. Two tree service companies have looked at it and given me removal estimates. However, there was no clear opinion on whether the integrity of the tree is compromised enough to warrant removing it. The tree is at least 50 years old. What are your thoughts?


A: Obviously, the two tree service companies like to take trees down rather than attempt to save them. I would try a company that has an International Society of Arboriculture certified arborist. To get a listing for your area, go to

If the vertical cracks go into the heartwood of the tree, there is a chance the tree is rotting. If that is true, removing the tree would be highly recommended. If the cracks are just in the bark and have healed, then the tree probably is sound. Increment borings taken by the arborist can determine if the interior of the tree has started rotting. Standing and looking at the tree without such a test is not a valid determination because too much of the tree is hidden.

Q: We recently purchased a home that has a row of junipers mixed in with long-needle spruce trees. As a result, the junipers and the spruce are stunted. We would like to move the junipers but are not sure if the roots are too intertwined to move. Do you have any suggestions on how to move them so that all of the trees survive?

A: Trees with intermingled roots that have been in the ground for a long period of time do not transplant well at all. The grafting of roots occurs within species, so a lot of root damage is bound to occur during any transplanting.

This also is something that beginners should not attempt to do. You would be better off hiring a landscape contractor or someone who has a small landscape business to do the transplanting or removing the trees.

The stunting could come from deciduous trees or surrounding structures casting too much shade because spruce and juniper trees are planted adjacent to each other a lot.

Q: What does "when the fruit has set" mean?

A: It simply means that the fertilization of the flower was completed, so the fruit is now developing from an embryonic size to harvestable size. In common parlance, growers often will view a tree, vine, shrub or plant and say there is a good fruit set upon seeing the large number of developing fruits.

Q: I've had a mammillaria pilcayensis for about seven months. For a while, it was growing well. Every few days or so, I would rotate it because it would start to lean toward the sun. However, for the last couple of weeks, I haven't needed to rotate it because it's staying leaned away from the window.

I'm wondering if there's something I can do to help it grow straight again. Having read most of the other e-mails you have answered, I realized that I've probably been overwatering it. Could that cause it to stay leaning? The store where I bought the plant had glued a dried flower on it. After a few months, I carefully removed it because it looked silly once the cactus started growing and I figured it wasn't doing anything for the plant. When I pulled it off, about four groups of spines came off with it and haven't grown back. I read that the spines are important for protecting the cactus from the sun. Could this little bald spot be hurting my cactus?

A: I don't think that would be the cause of your problem. If it is, the problem should correct itself. I would try a plant light directed at the cactus. It could be that the light coming in through your window is too weak to have a tropical effect. I'm assuming you live up north with us where the moonlight is now almost brighter

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 e-mail