Growing Together: Truisms to grow by

"Be careful with that pencil or you'll put an eye out." "And never run with scissors." These are truly wise words. Gardening has its own truisms that increase our success with all things green and growing. These "rules to grow by" can be passed a...

Annual flowers, such as zinnias, will bloom longer if spent flowers are removed before they set seed. David Samson / The Forum

"Be careful with that pencil or you’ll put an eye out.”
“And never run with scissors.”
These are truly wise words. Gardening has its own truisms that increase our success with all things green and growing. These “rules to grow by” can be passed along as gardening wisdom from one generation to the next.
Did I hear someone say they don’t have a green thumb? Never true. The first rule of gardening defines a green thumb as simply providing a plant’s needs through instinct, experience or education. And we can all do that.
Tried-and-true gardening wisdom includes the following:

  • More indoor plants are killed by overwatering (meaning too frequently) than any other cause.
  • When watering a potted plant, always apply enough to wet the entire soil ball.
  • Never let a potted plant stand in water more than a few minutes once soil is moistened.
  • Clay pots are more forgiving of watering errors than plastic because they breathe.
  • Flowering plants will bloom quicker if slightly pot bound.
  • When trying to decide pot size, don’t let plants flounder in a too-large pot.

Lawn care

  • Three inches is the optimum mowing height for healthy turf.
  • Deep, less-frequent watering promotes healthy, deep roots. Frequent, shallow watering causes shallow, less-developed root systems.
  • If lawnmower clippings are allowed to filter back into the lawn, their nutrient level equals one fertilizer application per season.
  • Broadleaf lawn weed killers that don’t harm grass can kill or damage shrubs, flowers and vegetables if vapors drift onto non-target plants.

Trees and shrubs

  • Fast-growing trees are usually shorter lived than slow-growing types. There’s a place for both.
  • Overgrown deciduous (leafy) shrubs can be rejuvenated by cutting back to 6 inches above ground level before spring growth begins. Not so with evergreens.
  • Most deciduous pruning is best done in early spring before “bud break.”
  • Prune evergreens in May and June.
  • To determine proper tree planting depth, the widened flare between trunk and roots should be visible above soil level.
  • The “feeder” roots of a tree are much closer to the canopy’s drip line than to the trunk.

Fruit trees

  • Most apple trees require five to seven years from planting until full production, depending on variety.
  • Apples require cross-pollination from a different apple variety to set fruit. Ornamental crabs will work, or a neighbor’s apple tree, providing it’s a different type.

Annual flowers


  • Another name for annual flowers is bedding plants.
  • Annual flowers that grow quickly enough to direct seed into outdoor soil include zinnia, cosmos, nasturtium and four o’clock. Most others require pre-started transplants.
  • Annuals will continue blooming longer if spent flowers are “deadheaded” before they set seed.

Perennial flowers

  • Some types are long-lived; others persist only a few years.
  • Perennials that bloom in spring and early summer are best divided in fall. Conversely, those that bloom in late summer or fall are best divided in spring.
  • The greatest challenge with perennial flower beds is usually weed control.
  • Peony tops should be removed in the fall for disease sanitation.
  • Hosta, daylily, and iris tops are best cut back in fall. They’re too mushy by springtime.
  • Other than those mentioned, most perennials will survive winter better if tops are left intact and cut back in springtime.

Vegetable gardening

  • Soil is ready to work in spring if a handful, when squeezed into a ball, crumbles apart easily rather than staying in a mudball.
  • Overhead sprinkling can spread disease organisms by splashing water. Ground watering and soaker hoses are better.
  • Morning watering is preferred because evening water can cause foliage to remain wet all night, increasing disease chances. 
  • New plantings of rhubarb and asparagus should be allowed to grow two full seasons, and harvesting can begin the third. 
  • Stop harvesting rhubarb by July 4. This allows plants to replenish vigor during the season’s last half. 
  • Asparagus tops are best left on over winter and removed in early spring.
  • The number of days to maturity on a tomato variety tag is from the date of transplanting plants to the garden, not the days from seeding. 
  • Clear plastic warms soil faster than black plastic, when used as a soil mulch to speed growth of heat-loving crops like melons. 
  • If radishes grow into all tops and no bottoms, they usually weren’t thinned early enough, or the weather was too warm. Plant earlier and thin plants to an inch or more apart.
  • Don’t sneeze with your eyes open, or your eyeballs will fly out of their sockets. That has little to do with gardening, and I’m not sure of its accuracy. I just wanted to see if you were still paying attention. 

Do you have a favorite gardening truism? Please email me, and maybe we can publish Part 2 at a later date. Don Kinzler, a lifelong gardener, worked as an NDSU Extension horticulturist and owned Kinzler’s Greenhouse in Fargo. Readers can reach him at .

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