Spring bulbs can be planted until December, as long as the ground doesn’t freeze. But the longer they are out of the ground, the greater the risk of rotting. If you can’t plant right away, keep the bulbs in the fridge, not the freezer, and plant early spring bulbs and daffodils before tulips.

Plant between three and seven inches deep, depending on the size of the bulb. If squirrels are a problem, plant tulip and crocus bulbs deeply, at least six inches.

Plant in clumps, or in massed drifts or grid patterns. Don’t plant in single lines; the effect is too weak. A common mistake is planting too few of a given variety; think big.

Daffodils can be planted in grassy meadows that are left unmown until June. For bulbs in lawns, try Crocus tommasinianus.

Perennial bulbs will persist in light shade but will peter out when planted in deep shade or if their foliage is smothered by other plants in May.

A sturdy trowel is fine for planting small bulbs, but for tulips and large daffodils, use a bulb planter. A long-handled planter is the best tool.

Spring bulbs work in containers, but use a large container and make sure it drains freely and is frost-proof. Plastic, fiberglass or wooden containers work fine. Set the bulbs deeply and keep them from touching. Tie netting over the pot to thwart squirrels. Remove it in late winter.

Look for named varieties at local garden centers. Here are a few mail-order sources: Brent and Becky’s Bulbs (www.brentandbeckysbulbs.com); John Scheepers (www.johnscheepers.
); McClure & Zimmerman ( www.mzbulb.com ); White Flower Farm (www.whiteflowerfarm.com).

— Adrian Higgins