Exercise your green thumb in winter with 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 at least 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 because the ethylene gas emitted by ripening fruit can damage the flowers, as can cigarette smoke.
• Continue cutting buckthorn out of native and garden areas during the winter. There will be less impact on herbaceous native plants when this work is done on frozen ground, which means you may need to curtail work in some areas if the ground is wet and unfrozen.
Working on soil that is soft and wet will damage the soil structure and any dormant plants that are present. Treat buckthorn stumps with an herbicide such as glyphosate or triclopyr to kill the root system or the buckthorn will vigorously grow back as a shrub.
Glyphosate needs to be used at a high enough concentration to work as a stump treatment. Some recommend a 50% concentration, but Chicago Botanic Garden staff has had success with a lower concentration of around 30%. One of the drawbacks of glyphosate is that it is water-based and will freeze and is only effective on the cut surface.
Triclopyr herbicide formulated for oil dilution works very well in winter, as it is effective through the bark and on the cut surface and will not freeze.
• Keep any logs you save for fireplace burning outside of your home until you are ready to use them, as insects can come in with the firewood. Never treat firewood with an insecticide.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.