How to extend the beauty of cut flowers

To keep cut flowers fresh, place them in room-temperature water as soon as possible. Protect the cut flowers from exposure to freezing temperatures outside. With a sharp knife or pruners, make an angled cut and remove a minimum of 1 inch from each stem.

Ideally, make this cut while the stem is under water. Cutting on an angle increases the surface area for water intake. Add floral preservative to the vase water. Most preservatives contain an acid (to neutralize alkaline tap water) and an ingredient to discourage bacteria.

Remove all foliage below water level. Cut flowers prefer a cool, humid environment and should be kept out of bright light and away from heating vents. Do not place cut flowers close to a bowl of fruit or vegetables since the ethylene gas emitted by ripening fruit can damage the flowers, as can cigarette smoke.

• You can cut buckthorn out of your garden and native areas all winter long. There will be less impact on herbaceous native plants when this work is done on frozen ground.

Be sure to treat buckthorn stumps with an herbicide such as glyphosate or triclopyr to kill the root system. Glyphosate needs to be used at a high enough concentration to work as a stump treatment. Some recommend a 50 percent concentration, but Chicago Botanic Garden staff has had success with a lower concentration of around 30 percent. Be sure to completely read and follow instructions on the product label.

Two drawbacks with glyphosate are that it is water-based and will freeze at low temperatures and that it is only effective on the cut surface. Triclopyr is a good alternative because it is effective through the bark and on the cut surface and will not freeze when mixed with oil (diesel fuel, fuel oil or kerosene) or oil/water mixtures. Complete your work when temperatures are above freezing to avoid this extra step of mixing with an oil.

• Many apply too much ice melt to their walks, which then increases the chances for damage to plants, paved areas and walks. Ice melt products with calcium chloride tend to be easier on plants, so this is what I use at home. Try mixing ice melt with sand to control ice while reducing the amount of chemical used.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.