How to keep your Valentine's Day flowers vibrant

To keep Valentine's Day cut flowers fresh, protect them from freezing outdoor temperatures as you bring them home. Place them in room-temperature water as soon as possible. With a sharp knife or pruners, remove a minimum of 1 inch from each stem with an angled cut. Ideally, make this cut while the stem is under water. Cutting on an angle increases the surface area for water intake.

Add a 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 so it does not rot.

Cut flowers prefer a cool, humid environment and should be kept out of bright light and away from heating vents and areas with cold drafts. 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. Cigarette smoke can also damage cut flowers.

• So far this winter, there has not been an unusual amount of cold weather, but there is still plenty of the season left. The more recent cold weather may damage plants that are at the edge of or out of their hardiness range, but should have little to no effect on other plants.

Many gardeners like to push a plant's limits in order to have more unusual specimens in their collection. There is nothing special to do now to help these plants. The good snow cover we currently have will help plants get through the winter.

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