Valentine's Day was just five days ago, and flowers all around Penn State are beginning to wilt in their vases.

But with a little post-harvest care, they might be able to last longer.

"Good quality roses can last at least a week if you take good care of them," Kathleen Brown, professor of post-harvest physiology, said.

When choosing roses, make sure there is a thick stem and head.

If the stem is thin compared to its head, that's a bad sign, Brown said.

The first step in taking care of roses, or any other types of cut flowers, is to get them back into water as soon as possible.

"Once flowers are cut, they are removed from their water source, so they need to get back into water as quickly as possible," Robert Berghage, associate professor of horticulture, said.

Usually a packet of preservatives comes with flowers and should be mixed with warm water inside the vase.

A homemade recipe for vase water is to fill it halfway with water and halfway with Sprite, Brown said.

Before putting the flowers into the vase, the lower leaves should be stripped off.

These lower leaves can cause microorganisms to grow, which will plug up the stem of the flower, Brown said.

In addition to the leaves, at least an inch should be cut off the bottom of the stem.

It is not necessary to make the cut diagonal. This only helps the stems from sealing to the bottom of flat vases, Brown said.

Flowers should be displayed in a cool place, which helps the water to move up into the flowers faster, Brown said.

He added that putting flowers on a television or heater is not the best idea.

Vase water should be changed daily, or whenever it begins to look cloudy.

"The biggest key to keeping flowers fresh, it to keep them clean," Berghage said. "Bacteria and algae that grow in the water plug up the vascular system."

Another tip is to use distilled water instead of tap water. Distilled water is cleaner and has lower ph levels than regular tap water, Berghage said.

Carnations, chrysanthemums and daisies are common cut flowers that come in a variety of colors and last for up to two weeks.

Freesia is a cut flower that smells great but might not last as long, Brown said.

Although freshly cut flowers eventually die, they can be dried and still look beautiful.

"The best way to dry flowers is to hang them upside down," Berghage said. "This is to keep their stems straight more than anything else."

Flower should be dried in a dry place.

Drying flowers in a damp basement would cause molding, Berghage said.

A creative way to dry flowers is to weave them into a wreath.

This should be done when flowers are still somewhat moist, which makes them easier to arrange.

When the flowers in the wreath have completely dried, hairspray can be applied to help the flowers from falling apart, Berghage said.

For more information on the post-harvest care of cut flowers, visit the Society of American Florists Web site at www.safnow.org.