Monthly Gardening Calendar
Sharon Morrisey, Consumer Horticulture Agent
University of Wisconsin-Extension in Milwaukee Co.

March, 2002

Winter never really arrived so it is hard to tell when spring is truly here.  The fluctuating temperatures are hard on trees and shrubs started to open their buds.  A late freeze will surely nip some spring flowering favorites.

Tulips and daffodils have already sent up several inches of leaves.  A freeze could brown them a little but being early spring flowering plants anyway, they are tougher than they seem.

While you wait for spring, plant some pansies in a pot if you can find them.  They are much tougher than their name implies since they can take what March dishes out including snow and freezing temperatures.

The very first thing gardeners can do is select seeds and get a few vegetables started indoors.  Onions could have been started in February if you were really on top of things.  Otherwise, start now and keep them clipped down to 4” until the end of April when they can go outdoors into the garden.  There are many more seeds to sow indoors in the third and fourth weeks of this month.

Get a jump on spring by setting up a cold frame. Build one yourself or buy one that's a little more high tech. An old storm window supported on straw bales works pretty well, too.  They are great for starting seeds of cole crops and to get very early lettuce and spinach for fresh salads.

If you need more room to garden, consider renting a plot from your community gardening organization.  In Milwaukee County, call the UW-Extension's rental gardening program at 290-2405. 

Use the numbers given after a calendar entry to get more information through the UW-Extension InfoSource educational phone message system.  In metro Milwaukee, dial 290-2450 and follow the instructions.  Check out the daily Dial-A-Garden-Tip, topic #791, for a different timely gardening message every day.

Visit the UW-Extension's Horticulture Web page at www.uwex.edu/ces/wihort/.  InfoSource messages for the garden calendar entries can also be accessed here and downloaded for future reference.

First Week 

Take bulbs out of cold storage for forcing as soon as they have had a long enough cold period.  The smaller bulbs like hyacinth and crocus only need 8 weeks of cold while tulips and daffodils need 12 - 14.  Paper white narcissus do not require this chilling so can still be purchased and potted up to grow and bloom yet this spring.

Tender bulbs of tuberous begonias, caladiums, dahlias, and canna lilies can be potted up in well-drained soil rich in organic matter.  Discard any that have rotted in storage.

If you have been storing geraniums in cool, dark conditions, its time to pot them up, cut them back and start watering again.

Cut back geraniums and coleus that you have kept growing indoors through the winter to only a few buds. This will stimulate new growth and a fuller plant by the time summer arrives.  

The longer days and shorter nights now will stimulate houseplants to grow more rapidly again so you may resume fertilizing. Use fertilizers at only half-strength and only every other watering. If March is cloudy plants will still use less water and therefore less fertilizer.

Continue feeding your holiday plants like Christmas and Thanksgiving cacti, poinsettias, cyclamen, azalea and amaryllis.  After flowering they start actively growing again and therefore need more nutrients.

Second Week  

The end of the dormant season is the best time to prune almost all trees and shrubs.  Pines are about the only exception.  Let their new growth expand until young needles are half of full size before pruning.

Spring flowering shrubs can be pruned now, too, unless you can't stand losing the flower buds on the stems you are removing.

Branches cut from spring flowering shrubs and fruit trees can be brought in and put in warm water to force them into bloom.  

Do not use tree wound dressing or paint on pruning cuts.  These can actually slow the healing process.

Elm, maple, birch, and black walnut ooze sap when pruned in the spring due to water pressure from the moist soil.  It will not harm the plant but you can prune these in early summer or late fall instead if you are bothered by it.

Some insect pests of trees and shrubs are best controlled by spraying with dormant oil.  This includes scale insects of pine, lilac, and euonymus and many of the gall-forming insects.  These insects reside on stems or needles and are smothered by the oil. Galls are mostly a cosmetic problem but scales can weaken plants. Check weather forecasts to be sure temperatures will stay above freezing for 8 - 12 hours after spraying to avoid damaging stems and needles.

Prune out and burn or bury the brown, shriveled "witches-brooms" on honeysuckle.  The leaf-folding aphid that causes these overwinters in these growths.  They feed on new growth as soon as the buds break in the spring.  This one is hard to control since untreated honeysuckles are everywhere.  This may be a good time to consider replacing honeysuckles with less invasive plants with fewer pest problems.

Sow seed for parsley in pots on a bright window sill.

Third Week  

Make St. Patrick's Day a floral holiday with shamrocks and other assorted foliage plants.  Kids get a kick out of making their own "Irish" carnations by using white carnations and a vase of green food coloring and water.  At the same time they learn that plants suck water up and move it through the whole plant.  

Start planning the vegetable garden.  Be sure to include your children or grandchildren in the process this year.

Seeds of the following annual flowers can be started indoors:  ageratum, wax begonia, browallia, dianthus and carnation, dusty miller, impatiens, larkspur, lobelia, dwarf marigold, nierembergia, pansy, petunia, moss rose, snapdragons, and stocks.  Be sure to use a sterile seed starting medium, supplemental lighting, and bottom heat for best results.  Different species also have different requirements for light or darkness during germination.  Look up the varieties you have on the seed packet, in a seed catalog or a good reference book.

Tops of onions seeded last month should be clipped to keep them at about 4 inches.  This diverts energy to bulb growth.

Fourth Week  

Sow seeds indoors for the following vegetables:  broccoli, cabbage, cauliflower, celery, eggplant, and head lettuce.

Sow seeds indoors for the following flowers: alyssum, verbena, calendula, celosia, coleus, dahlia, phlox, and salvia.  

Be mindful of warm days when the sun can cause heat to build-up under rose cones, cold frames, and in other plant protection systems.  However, avoid removing mulches prematurely from plants with tender new tissue forming.  

Examine lawn areas where water may have pooled or snow cover lingered.  Snow mold fungus may develop in these areas.  Also look for meadow mouse tunnels in the browned grass.  Both can be improved by roughing up the affected area with a rake to encourage the adjacent healthy grass plants to fill in.  

Take your lawnmower in for servicing to avoid the rush at the repair shop on that first nice weekend of April.  Get it tuned up, the oil changed, and tighten all bolts. At the very least, get the blade sharpened.

On nice days, go outside and turn the compost pile.  This will get it "cooking" again.  Hopefully, it will also help you resist the urge to start working the soil too soon.
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During inclement weather, clean-up and sharpen garden tools and prepare other gardening equipment for the busy months ahead.  Inventory pesticides, fertilizers, bags of potting soil and amendments.  Finish up last years records.  And there is still time to do a little dreaming and planning.  

If you need more room to garden, consider renting a 20' x 20' or 30' x 30' plot from Shoots 'n Roots, Milwaukee County UW-Extension's rental gardening program.  Call 290-2405.  In Waukesha County, the UW-Extension's rental gardening program can be reached at 548-7775.