How to Plant Tomatoes: 8-Step Beginner Guide

Six weeks before your last frost is the sweet spot for starting tomato seeds. Fill a plastic cup with quality potting mix that already has a bit of fertilizer in it. Cut a few holes in the bottom for drainage.

Sprinkle the seeds on top, give them a pinch of mix to cover, and mist with water. Set the cup on a seedling heat mat (tomatoes want 70-80 F to germinate) and cover with a plastic dome or bag to hold humidity. You'll see sprouts in 5 to 8 days.

Once each seedling has its first set of true leaves, move them into a cell tray filled with potting mix. Tease the seedlings apart gently - the roots are fragile at this stage.

Tomatoes grow new roots all along their stems, so bury each seedling as deep as you can in the new cell. The deeper the stem, the bigger the future root system. Label each cell so you remember which variety is which.

About a week before you plan to plant outside, start hardening off. Move the seedlings outdoors for a few hours a day, picking up sun exposure gradually.

The first day might be just an hour in dappled shade. By the end of the week they should be tolerating most of a day in direct sun. Skip this step and the leaves will scorch the moment you put them in the garden full-time.

Pick a spot that gets at least 6 to 8 hours of direct sun. Amend the bed with compost, aged manure, and bone meal so the soil is rich and loose - tomatoes are heavy feeders.

Dig a hole deep enough that two-thirds of the seedling stem will sit underground. Mix a scoop of granular fertilizer into the bottom of the hole - one that's higher in phosphorus and potassium than nitrogen. Too much nitrogen gives you a leafy plant with no fruit.

Snap or pinch off the lower branches of each seedling so the bottom two-thirds of the stem is bare. This is the part that's about to go underground.

Don't skip this. The buried section will sprout new roots wherever the stem makes contact with soil, and that extra root mass is what lets a tomato plant pull water and nutrients through a hot summer without wilting.

Drop the seedling into the hole so the bottom two-thirds of the stem is buried. Backfill with the amended soil and firm it down around the base.

Space plants 2 feet apart for staked single-stem varieties, or 3 feet apart if you're letting them grow as a bush. Give each one a deep drink of water immediately to settle the roots and eliminate any air pockets in the hole.

Cage, stake, or trellis - pick one and install it the same day you plant. Tomato plants get 4-9 feet tall depending on variety, and trying to add support after they've grown means breaking branches and disturbing roots.

Cages are the easiest option for beginners. Stakes work for indeterminate varieties pruned to a single stem. Either way, a fallen tomato plant on the ground is a magnet for slugs, fungal disease, and rot.

Tomatoes want a deep soak once a week, not a daily sprinkle. Shallow watering trains roots to stay near the surface where they dry out fast. A long deep drink sends them downward.

Water at the soil level, not the leaves. Wet leaves invite fungal disease. Mulch the base of each plant with straw or compost to hold moisture, suppress weeds, and stop soil from splashing onto leaves when you water.