Gather your seeds and supplies: It’s nearly prime time to start seeds for this year’s garden. Most seeds are best planted somewhere around six to eight weeks before the last spring frost.

Nothing is more disappointing than beginning the garden season by starting seeds with high hopes and dreams of a wonderful garden, only to have just a few seedlings emerge and even fewer plants survive into May. Follow these steps to grow healthy seedlings indoors:

• Use only soilless mix, not potting soil, garden soil or previously used potting mix.

Seeds and young seedlings are easily killed by a plant disease known as damping-off, which is caused by soil-borne pathogens. These pathogens occur in mineral soils, such as the black soil in that bag of potting soil or soil from the garden.

Damping-off kills seeds before they emerge from the ground, but it can also cause small seedlings to rot and die. These seedlings often collapse at the ground level as if they need water, but in fact the damping-off pathogens have rotted the roots and stems.

Avoid damping-off by using only sterile, soilless mix, such as seed-starting mix.

• Don’t start seedlings too early.

Some seeds need to be started very early in the season, such as geraniums, which should be started 10-12 weeks before the last frost. Most seeds, however, perform best when planted six to eight weeks before the last frost.

And some, like cosmos or marigolds, perform just as well when planted directly in the garden in mid-May.

Seeds planted too early tend to get weak, and don’t outperform younger, sturdier plants started with ideal timing.

Not sure when to start those tomato or lupine seeds? Check the back of the seed packet for all the details.

• Don’t reuse containers until they’re clean.

Containers previously used to grow plants are most likely contaminated with the pathogens that cause damping-off.

Planting in dirty containers is a perfect way to introduce pathogens to clean soil, so wash all containers with soap and hot water, then rinse them in a solution of one part bleach to 10 parts water.

• Clean all other items used in seed starting.

This includes small watering cans, planting tools or reused labels. While you’re at it, wash the seed-starting area, including trays and shelves, with the bleach/water solution.

• All containers need drain holes.

As cute as it may look to plant seeds in a coffee cup or cereal bowl, it’s almost guaranteeing failure by water-logging plant roots. Roots need air spaces as much as they need water, so be sure all containers have drain holes. Add holes to yogurt containers or other recycled containers.

• Keep seedlings under fluorescent lights.

Although it might seem bright on the kitchen windowsill, this location rarely provides enough light to encourage healthy, even plant growth. Seedlings perform best when grown under fluorescent lights.

These fixtures can be suspended from a shelving unit to be about three inches above emerging seedlings. As plants grow, raise the lights to maintain the intensity.

Special grow bulbs aren’t necessary to start seeds; basic shop lights will suffice.

• Harden seedlings before planting them outdoors.

The warm, sheltered life seedlings lead inside does little to prepare them for the harsh realities of garden life. To help seedlings make this transition, harden them gradually over seven to 10 days.

Cut back on water and fertilizer, and expose plants to increasing amounts of sunlight, rain and wind each day. Tender plants need time to adjust to real-world conditions; the hardening helps them get ready for the move to the garden.