Before you consider sticking a plant in a container, try to digest a fair share of basic planting advice. (Click here for preplanting information in detail)

Follow these steps for most shrubs, trees, annuals, and perennials:

• Prepare the container.
  
  Soak new terra-cotta pots in water for 10 or 15 minutes before planting to prevent clay from absorbing moisture from the soil mix. If you’re using old pots, clean them to remove salt deposits and rinse with a 10 percent bleach solution to reduce chances of disease. Apply preservative to wood containers before you plant.
• Check the drain hole to make sure that it’s the right size.
  
  Most commercially made pots have drain holes to allow water to flow out of the container. Don’t ask why, but these holes usually are too big, allowing too much water to escape. You need to partially cover the drain holes to keep soil mix from slipping through. Use a piece of fine-mesh metal screen large enough to cover the hole, or cover the drain holes with pot shards (pieces of broken pot). You can also use a rock with an uneven shape that doesn’t completely block the hole.
  
  If your container lacks a drain hole, you need to make one. In the base of a wooden box, drill one 1/2-inch hole for a box up to 12 inches square; two to four 1/2-inch holes for larger boxes or a half barrel. For clay pots, use an electric drill with a masonry bit. Support the pot on a block of wood, and start drilling with a smaller bit, eventually reaching the final size of 1/2 inch; adding water to the drill hole may help.
• Make sure that the nursery plant’s soil is moist enough to hold the roots together when you plant.
  
  If the soil is dry, soak it thoroughly, and let it drain for at least an hour.
• Remove the plant from the nursery container; inspect the root ball.
  
  Wet the soil and then tip plastic containers upside down, taking care not to break branches, and let the root ball slip out, catching it with one hand. Tap the rim of the container upside down on a hard surface if the root ball doesn’t slip out easily. If your plants are in plastic cell-packs, turn the pack upside down and wiggle the base of each cell. Tug gently, taking care not to break the stem or loosen the root ball. For small, root-bound plants, gently loosen the mat of roots with your fingertips. For larger plants, such as 1-gallon or 5-gallon shrubs, use a knife to score some vertical scratches in a tight root ball.
• Incorporate a complete food into your soil if your soil doesn’t include fertilizer.
• Check to see whether the soil mix is moist.
  
  If it’s dry, wet while it’s still in the bag by adding water and stirring or kneading the soil until it reaches the desired level of moisture.
  
  Do not use soil from your yard, because it tends to compact when in a container. Roots can’t penetrate this soil, and drainage becomes a problem.  ....read more