Jan’s online garden hints

Jan’s March Tips

-Top all mulches with a fresh layer to stop overwintering fungus diseases such as gray mold and leaf spot from spreading to new growth.

-Flush the soil in areas near sidewalks, driveway or street with water to wash away any deicing salts left over from winter’s snow and ice storms.

-If snow still covers the garden, scatter a light sprinkle of wood ashes saved from the fireplace on the snow.  Besides hurrying the melting, ashes add nutrients.  But add no more than a light sprinkle: too many ashes, like too much lime, make the soil too alkaline.

-Give tuberous begonias and caladiums an early start indoors.  Cover caladium tubers with an inch of potting soil.  Just press begonia tubers into the soil, hollow side up.  Water, then set the pots in a warm spot.

-If your roses aren’t disease-resistant varieties, apply a dormant lime-sulfur spray before new leaves unfurl to kill any overwintering black spot spores. Gradually remove soil mounded over tender roses in the fall.

-Remove last year’s withered foliage of iris, daylily and other perennials before new growth begins to prevent pest and disease problems. Also cut and remove dead tops of asparagus plants, if you didn’t do the job in late autumn. Delay raking mulch off perennials, though, which might encourage your plants to grow too soon and thus risk damage in a cold snap.

-Postpone digging and dividing chrysanthemums until nighttime temperatures stay consistently above 25 degrees Fahrenheit.

-Repair damaged trellises or other garden structures.  As soon as the frost is out of the ground, reset wobbly bricks or pavers in garden paths.

-Rake bare spots in the lawn as well as matted “snow mold” areas.  Add topsoil to any low spots, then reseed with a disease-resistant grass-seed blend.

-Repot houseplants that have outgrown their pots as the plants begin a growth spurt in response to longer days.  Trim away any roots that are too long to fit easily in the new pot.  Cover the drainage hole with a coffee filter or piece of paper towel or newspaper to keep the soil in place.

-If you have houseplants that haven’t yet outgrown their pots, wash away excess salts in the potting soil: Remove plant saucers and let the water run freely through the soil for a couple of minutes.  If the pot is too heavy to carry, scrape away the top several inches of potting soil and replace it with fresh.  Also resume fertilizing houseplants now that longer daylight is encouraging new growth.

-Root cuttings of houseplants such as wandering jew and purple heart to use in outdoor containers this summer.


-Suspend a large sweet potato in a jar of water, stem end up, with three toothpicks stuck into its “waist” to keep its “head” above water.  As shoots grow, take cuttings to root for the vegetable garden.

-If trees or shrubs such as euonymus or lilac have been plagued with scales, aphids or mites in the past, spray plants now with dormant oil.  Wait for a day when the temperature is over 50 degrees Fahrenheit and not expected to drop below freezing for 24 hours.

-Don’t panic if your evergreens look discolored.  Wait until late spring to give new growth a chance to cover any damaged needles.

Garden planting:

-As soon as a squeezed fistful of soil crumbles apart easily without caking, sow seeds of cool-season flowers and vegetables, including bachelor button, calendula, larkspur, lettuce, onion, pea, poppy, radish, spinach, and sweet pea. Also set out onion plants and sets. (Wait until next month to plant sugar snap peas; their high sugar content makes them more likely to rot in cold soil than other peas.)

-Prepare new beds by digging a 2-inch layer of compost into the soil.

-Plant a mix of salad greens in one bed, then cover with a floating row cover such as Reemay to boost the temperature and speed up the first harvest.  Anchor the fabric with large metal staples pushed through the cover and into the ground.

-If your soil routinely stays too wet for early spring planting, plan to build a raised bed where the soil can dry out and warm up faster.

-Provide stakes or branches for pea vines to climb.

-Save tedious hand weeding later on by hoeing or tilling the soil two times, starting several weeks before you plant, particularly where you’ll be planting small or slow-growing seeds such as beets and carrots.  Before tilling, spray the tiller blades with vegetable oil to reduce sticking and help prevent rust.

-Plant asparagus and rhubarb.  If you have old rhubarb plants that are no longer producing large stalks, dig and divide those plants.  If emerging rhubarb is exposed to freezing temperatures, discard any stalks that show signs of damage.


-Delay pruning lavender, butterfly bush, blue-mist shrub, and Russian sage until after new shoots appear.

-Prune established summer-blooming clematis vines back by half.  Prune autumn-blooming varieties back hard, to 3 feet or less.  (Postpone pruning spring-blooming clematis until after its flowers fade.)

-When pruning trees and shrubs, save small limbs to prop up floppy garden plants later in the season.


-Cut off everbearing raspberries such as Heritage at ground level and remove old canes from the patch.  (To avoid sacrificing the whole crop of a summer-bearing variety such as Latham, delay pruning of those raspberries until after the crop is harvested.)

-Clip ornamental grasses back almost to the ground.  If you’d like to skip tedious raking, tie all the top growth of each plant together with twine before you cut.  Dig and divide any grasses that have died out in the center of the clump.

-Inspect apple, cotoneaster, hawthorn, mountain ash and pear for the blackened branches typical of fireblight.  Prune 10 inches below any visible signs of the disease, sterilizing the pruners between cuts by dipping the blades in a 10 percent solution of chlorine bleach.

-To keep the lower branches of hedges healthy, prune so the shrubs are broader at the base than at the top.

-If you have old-fashioned roses that bloom only once a year, postpone pruning until immediately after the flowers fade this summer. If you have roses that bloom all summer, prune them when their leaf buds begin to swell. Remove canes that are weak, crossed, or damaged.  Make cuts at a 45-degree angle, one-fourth inch above an outward-facing bud.  Seal cuts with white glue to keep out carpenter bees and other boring insects.

-Control black knot in plum, cherry
and other Prunus species by pruning
2 or  3 inches below any black, swollen area.






Starting seeds indoors:

-Using a ready-made, soil-less mix formulated for seedlings, plant seeds indoors of tomatoes, peppers, and warm-weather annuals such as impatiens, petunias and flowering vinca.

-As soon as indoor seedlings sprout, provide plenty of light from a sunny window or, even better, a shop-light fixture with fluorescent tubes.  Adjust the fixture so the tubes are only 2 or 3 inches above the tops of the plants, and leave the lights on 12 to 14 hours a day.

-Keep young indoor seedlings healthy by avoiding the four things that encourage damping off: overwatering, poor air circulation, containers with no drainage, and crowded seedlings.

-If indoor seedlings grow too tall and leggy, decrease heat and increase light.  Another possibility: Move the seedlings outside to a cold frame.