Bulbs are harbingers of spring, says Barbara Pierson, nursery manager for White Flower Farm in Connecticut. Theyll flower before the leaves are on your trees. And theyre really a good return on investment, because they come back every year.

But dont wait forever to bury those bulbs, which gets more difficult as ground temperatures drop. To assure spring color, grab a spade and follow this advice:

Timing: The window of opportunity to plant bulbs is limited. Plant too soon, summer heat will turn bulbs to mush; plant too late, bulbs wont lay dormant long enough to store energy for brilliant spring blooms. The best time to plant is six weeks before the ground freezes. Or follow this rule of thumb: If you can still dig, you can still plant a bulb.

Soil: Sandy, acidic, and alkaline soil are fine homes for bulbs, which are not finicky growers. But bulbs dont like to sit in water; place bulbs in well-drained soil (hills are better than valleys). To increase drainage and lighten heavy clay soil, add humus and leaf mold.

Sunlight: Bulbs do best in bright, open spaces, but theyll flower in partial shade. The earliest bulbs, like crocus and galanthus, will bloom anywhere because most trees are still bare when they put on their show.

Planting tips

  • Select a firm, not mushy, bulb.
  • Dig a hole 2 to 3 times the height of the bulb, and insert the bulb pointy end up.
  • Cover.
  • Compact the soil (pressing with your shoe or boot works fine).

If youre long on time and short on funds (10 crocus bulbs cost $10), space bulbs 8 inches apart, and wait a couple of seasons for them to divide and fill in. Also, plant bulbs in irregular shapes; formal rows arent found in nature.

More bulb advice

  • If you miss the planting season, you can force bulbs to bloom indoors. Chill them in your fridge for 10 to 12 weeks; pot them in soil or water; and place in a sunny place.
  • Resist the temptation to cut drooping foliage after blooms are spent, which weakens bulbs. Instead, pair bulbs with annuals, like pansies, that will hide unsightly leaves. Trim foliage only after it turns brown.
  • For the earliest color, plant crocus and muscari, which can peek through snow.
  • If youre plagued by deer, plant daffodils, which they wont eat. Repel other critters by planting bulbs in chicken wire cages.
  • Use a hand-held bulb planter ($3) to place a few bulbs in the ground; if youre planting hundreds, use a spade ($15-$35) to dig wide holes that will hold dozens of small bulbs.