This is "commencement weekend" for gardeners, and it comes not a moment too soon. For most, it has not been an easy year, starting with a topsy-turvy winter that defied explanation, followed by an equally troublesome spring when disease struck many Washington-area gardens. Probably, every diehard gardener deserves an award for fighting every inch to keep things going.
Murphy's Law was always in the wings. You experienced the usual midsummer drought (remember late July?), followed by August downpours from the Shenandoah Valley. Japanese beetles and gypsy moths ravaged lawns and trees, as did lace bugs, black vine weevils and spider mites on evergreens and shrubs. April weather triggered unusually severe outbreaks of leaf spot disease on lawns, followed by June rains that caused more lawn damage. Finally, there was September and the 0.75 meager inches of precipitation that almost cost you your lawn; if you hadn't been sprinkling your renovated lawn every day, you would have lost it for sure.
Eight months of strenuous labor come to an end this weekend with a final mowing of the lawn, then tackling last-minute chores to safeguard vulnerable plants for the winter. Here is a list of chores from which to choose:
June-bearing strawberry plants have just finished forming the dormant buds for next June's harvest. Ever-bearing plants did the same, but that harvest is minuscule by comparison. What's needed now is a fluffy mulch of three- to four-inch thickness over the soil around strawberry plants. Shredded mulch is fine, but the preferred mulch is sawdust. If you use sawdust from any source, pick up a bottle of fish emulsion at the garden shop, cut the recommended rate in half, use a sprinkling can to apply the solution over the soil around strawberry plants, then mulch with sawdust. These wood fibers will absorb nitrogen from the soil come next April, so applying fish emulsion now "satisfies" the appetite of the sawdust. An organic compound, fish emulsion will remain in place through the winter.
Blackened foliage of begonias, dahlias and canna lilies reminds us that tubers and rhizomes should be carefully spaded from the soil, dried and stored for the winter. Dead foliage can first be pruned away, after which plants are dug without cutting into the tissue. Massage them to remove soil clinging to the tubers or rhizomes, then let them dry for a week before storage. Dust the rootstock with powdered sulfur to avoid disease outbreak, then store them in buckets or pots filled with dry sphagnum peat moss in a cool basement. Tuberous begonias should be resurrected in January, dahlias and canna lilies in early spring. Other tubers that should have been spaded from the garden and stored include tuberose, zephyr lily, coral-drops and acidanthera.
Wield the bamboo rake a last time and remove all leaves and debris around and under fruit trees, grape arbors and berry plants. Bits and pieces of dead leaves now harbor disease spores for scab (apples, hawthorn and mountain ash), and leaf spot on cherry trees; diseased apples on the ground are next year's source of black rot while anthracnose overwinters on diseased peaches. All should be removed for sanitary reasons. Grapes littering the soil around the arbor will convey black rot to the vine next year, as will mummified grapes clinging to canes.
Even though ornamental cabbage and kale border the flower garden, a final cleanup is necessary to eliminate disease problems next year. If your plants always seem to be under disease attack, chances are the spores have been spending each winter in the mulch. Using a steel rake, unearth as much mulch as possible in the bed, disposing of it with the trash rather than strewing on the compost pile. Don't be shocked to find several inches of woody fibers decaying in the soil as a result of many years' applications of mulch. Make a fresh start next year by mulching with salt hay in early June instead of shredded mulch.
Sanitation around trees is a priority because, apart from spraying with appropriate fungicides as leaf buds break in the spring, it is the only proven way of breaking the disease cycle. Leaf spot tarnishes the foliage of maples in the form of "tar spot" and "purple-eye," but both problems are easily halted by meticulous cleanup of the area now.
Hawthorn is disfigured by leaf spot, particularly English hybrids, but this, too, can be overcome with a sanitation effort now. Similar diseases strike crab apple, hickory, magnolia, oak and fruit trees, sanitation efforts for which would be very rewarding.
While premature leaf-drop doesn't occur that often with shrubs, November cleanup can only contribute to healthier plants next year. If your pyracantha (firethorn) shows black rather than orange berries, the problem rests with diseased plant material left on the ground a year ago. Check the soil or mulch now for withered leaves already infected with scab disease. Render the soil spotless now, also pruning away all blackened berries, and the shrub won't have the problem next year.
Of all garden areas, ground covers are traditionally the most neglected, and probably for good reason. Who wants to go tiptoeing through the ivy, pachysandra or vinca for fear of desecrating plants? If ground covers have been blighted and spotted these many years, you have reason to waltz through the plants now. Bring a trash can liner with you to bag all withered plant materials. A preventative fungicide spray next April will work wonders.
The much-publicized disease (anthracnose) overtaking dogwoods can be halted by thorough sanitation efforts. If your dogwood exhibited blighted leaves on lower branches last June or early July, chances are that the diseased materials are still within walking distance of the tree. The disease shows as irregular tan-to-brown areas along the veins and outer margins of the leaf blade; in cool, damp spring seasons the leaves frequently twist out of shape and are deformed.
Dogwood cleanup now will break the anthracnose disease chain for next year. Rid the soil of everything, including mulch applied earlier this year. The soil should be spotless for 25 feet in all directions. If you fertilized the tree earlier this month (except those newly planted), so much the better. The best defense is a healthy, vigorously growing dogwood that is neither over-watered or over-fertilized.
Raise the humidity now, not only for your family's personal health, but also for the winter survival of indoor plants.
If your humidifier is built into your home heating system, activate it now by opening the valve supplying water to the unit, then plugging in the electric cord. Make sure the drain plug is seated properly in the pan.
Other homes and apartments should activate portable humidifiers, especially in rooms where indoor plants are grouped.
Lacking a humidifier of any sort, you should double-pot indoor plants now. Fill the bottom tray with pebbles or stones to serve as a reservoir for moisture evaporation. Check water levels in bottom trays often over the winter to make sure there is a constant humidity source.
Remember, humidity levels below 20 percent offer perfect environments for mealybugs and spider mites to attack plants. If you pick up static electricity as you walk over carpets and rugs, humidity is already below 20 percent and the pests are about to happen. Raising the humidity stops the attack.
Use low humidity settings (one through three) on humidifiers when outdoor temperatures drop into the 20s, otherwise windows will ice up quickly.
Jack Eden is the host of "Over the Garden Fence" Sundays from 10 a.m. to 1 p.m. on WTOP Radio (1500 AM).