Weather Forecast


Hortiscope: African violets need to be divided to stay healthy

Q: I have a Miss Kim lilac bush by that has grown too tall. When is the proper time to prune it back? How low can I cut it back?

A: Anytime next spring after it blooms is when it should be pruned. You can prune it back to just above the crown. These lilacs are not supposed to grow too tall. I think you are the first person to complain about this beautiful plant getting too tall.

Q: I purchased a jasmine plant this past summer from a local greenhouse. It was in full bloom when I got it, but hasn't bloomed since. What can I do to get it to bloom? I brought it indoors for the winter, but could it survive outside in our area? It was heavily infested with mealy bugs, but I have most of that under control now. Any advice would be much appreciated.

A: Good idea bringing the jasmine plant indoors for the winter. It would not survive being outdoors during Fargo's winter months. Reblooming likely will take place later in the spring if it gets enough natural and supplemental light from a plant lighting system. Mealy bug infestations are difficult to control.

It requires the careful use of insecticides, as well as judicious pruning. Monitor the plant carefully. Should the mealy bugs become noticeable again, prepare a solution of insecticidal soap to dip the entire aerial part of the plant into. This will effectively eliminate missing any bugs.

Q: How deep do weeping willow roots grow?

A: This is not a question I can answer with any degree of accuracy. It depends mostly on the type of soil you have and the water situation. The water situation would include the annual rainfall pattern, amount of rainfall and your watering practices.

For the most part, weeping willows spread out more than they go deep. As with most root systems, weeping willows will develop in a soil environment where there is a balance of air and water, although the willow is more tolerant of saturated soils than most tree species.

This species of trees will go where the water is and follow the path of least resistance. If there is a water source under the ground that the roots have picked up in their exploration of the soil and it happens to be a sewer line break or septic leakage, the roots will proliferate in that nutrient-rich area.

Count on the roots spreading 35 to 50 feet from the tree's trunk. The depth of the roots depends a lot on variable factors. This species often is used along stream banks to prevent erosion because of its formidable root system.

Q: I am looking for help with an African violet problem. The plant is healthy, but the violets are becoming overgrown, overcrowded and hard to the touch in the crown. The new leaves and blooms can't force their way out of that tough, hard-leaf overgrowth. What's wrong?

A: The poor thing needs dividing! African violets, despite the popular myth that they are delicate houseplants that need fussing over, are almost weedlike in their native environment.

To divide the plant, allow the soil to dry slightly, then tap the plant from the container and place it on a workbench or open newspaper. Separate as much of the soil from the root mass as possible, then cut through the crown with a knife, scissor or small pruner. Take the divisions and plant them in a pre-moistened soil mixture.

Keep the soil moist for a few days. Then allow the soil to remain slightly dry for the next couple of weeks so the plant can recover from the shock of division and transplanting. If you have a multi-crown plant, divide the multiple crowns by hand and repot.

Q: I mistakenly cut the center leaf of my spider plant. It looks like I snipped off the new growth. Does the plant grow from the center and will it recover?

A: If it was healthy, it will recover and grow new foliage.

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