University of Vermont Extension 
Department of Plant and Soil Science

Summer (late) News Article
Dr. Leonard Perry, Extension Professor
University of Vermont
Have you ever wished you could enjoy the beauty of summer flowers year-round? You can, if you preserve garden flowers now while they're in their peak of bloom. Because flowers and plant parts respond differently to drying and preserving methods, you may need to experiment for best results with method and time of harvest. More than one method may work with many flowers.
Start with top quality plants. Choose fresh, unwilted, undamaged flowers and foliage from your garden, farmer’s market, or cutting field at a farm stand. Collect plant materials on a warm, sunny morning after the dew has dried. Dampness encourages mold and slows the drying process.
Try to cut flowers just before they are fully opened. Always gather more material than you think you'll need for your arrangements and wreaths since some shrinkage and loss of plant material will occur. Tall artemisia or wormwood is useful as filler in arrangements and wreaths.  Harvest when the seedhead is fully developed, and air dry.
Air drying is the easiest and most popular method of drying flowers. It is generally the best method to use for flowers with strong stems such as cockscomb or celosia, globe thistle, sea lavender, liatris, sunflower, tall sedum like ‘Autumn Joy’, Joe Pye, and yarrow.  Air dry those with small flowers in clusters such as baby's breath, larkspur, statice, salvia, or lavender.  Also air dry dock, goldenrod, grasses, dusty miller, sedges, cattails, and hydrangea.  Pick hydrangea when it is getting a papery feel, as picking before this stage may cause it to wilt.
After cutting the flowers, strip the foliage from the stem, then tie a few stems together with a string or rubber band. Hang upside down on a hook, clothesline, or coat hanger for several weeks in a warm, dry place with good air circulation, such as an attic, garage, or old barn. Keep out of direct sunlight, and preferably below 85 degrees (F).  Flowers such as hydrangea and yarrow dry best when placed upright in a jar filled with one-half inch water that is then allowed to evaporate. If an enclosed or indoor space, you may need to use a dehumidifier on humid days.
To dry dahlias, plumed celosia, zinnias, roses, marigolds, and other flowers with thick heads or delicate blooms, use a drying agent--borax, white cornmeal, rice, or silica gel (available at craft shops). These materials draw the moisture out of plant tissues while still retaining flower color.  Others good for such such preservatives include salvia, annual larkspur, and delphinium.
Spread the drying agent about an inch thick in the bottom of an airtight container.  Don’t use wooden or cardboard containers, as they will allow moisture inside.  You may want to use a mask if working with silica gel, and don’t reuse the same container later for food. 
Select blooms approximately the same size and type, and remove the foliage and most of the stem except for about an inch. Place the blooms on top of the layer, and cover completely with more drying agent. Seal the container, and place in a cool, dark place.  In about a week's time, the flower petals will be dry and crisp. Gently pour off the agent, and remove the dried flowers, or remove with a slotted spoon.  Some then spray blooms with a fixative, such as hair spray.  Store preserved blooms in an airtight container with just a bit of drying agent on the bottom.  To hold the blooms upright in arrangements, use 20 or 22 gauge florist's wire.
If you want instant results, you can microwave the flowers with silica gel in an oven-proof or glass container. Preheat one inch of the silica gel on high for one minute or until crystals turn blue. Place a flower on the warm crystals, and cover completely with silica gel. Cook for one to three minutes, then let stand for up to 25 minutes (time depending on flower type).
Or preserve summer flowers by pressing them between layers of paper towels or newspaper, in a wooden flower press or between heavy books. Flowers with fine, delicate flowers or a single row of petals lend themselves to pressing.  Examples include fennel, pansy, viola, wild roses, dianthus, lavender, and alyssum. Foliage such as fennel and ferns can be pressed too.  Pressed and dried birch leaves can be strung with fine wire into a fall garland.
Select only perfect specimens for pressing, but keep in mind that while orange and yellow blossoms will retain their vivid color, most blues, purples, and pinks will fade, and reds may turn a muddy brown.  Leave your flowers in the press for four to six weeks. If the material is very fleshy, you may need to change the paper after the first 24 to 48 hours to prevent mold growth.
To preserve woody stems of leaves and fruit, cut the ends and place the bottom four to five inches of basal stem in a glycerine mixture until the plant has a glossy appearance and a leathery feel to all its leaves. To make the mixture, combine two parts water with one part glycerine (available at most drug stores), and blend thoroughly. Save the glycerin solution for future use by adding a few drops of bleach.
While collecting and preserving flowers and foliage, don’t forget to collect non-flower items too for later decoration such as cones, acorn caps, milkweed pods, and seeds. 

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