when to start seed

A Way to Garden when to start seed calculator

NEED HELP remembering when it’s safe and smart to start your first spring sowings of vegetable, flower and herb seeds indoors and out? This tool calculates when. Begin by entering your final spring frost date on the top right of the chart below. (Don’t know? Search by state with the tool at this link.)

The chart dates below suggest earliest springtime sowings, but there is no hard-and-fast rule whether lettuce needs 4 or 6 weeks indoors—or if you never give it a headstart, but simply direct-sow. This is my best guidance, not doctrine; that’s why my website is “A Way to Garden,” not “The Way to Garden.”

Note: Reemay or other protective row covers can “cheat” the earliest transplant dates by as much as 2 weeks, especially helpful with tender things like melons (or insect-prone brassicas and cucurbits).

Many crops (salads, carrots, beets, bush beans, cilantro…) are best sown in succession, a small amount every 2 weeks, starting at the chart date. In some climates, a later sowing timed for fall or winter harvest (e.g., Brussels sprouts) may do better than a spring one, or you can get a second sowing in of peas that you sowed in spring, then pulled.

I’ve added a list of how-to story links below, including some on stashing your harvest. Again: Start by entering your final spring frost date below (mine’s about Memorial Day). You can print your results using the button under the chart (it will be about 5 pages).

a spring garden calculator

how to sow, harvest and store vegetables

seed-starting gear i use for best results

HYDROFARM T5 HOODS: Hoods with T5 high-output tubes range from 2 to 4 feet and with 2 to 8 bulbs. Must be fitted with hardware to raise and lower from a stand or shelf you provide.
GROWEASE SELF-WATERING SEED STARTER: A felt-like capillary mat between cells and lower water reservoir wicks moisture up to seedlings. (Sizes up to 24 cells/flat.)
SOLO 2-LITER ONE-HAND PRESSURE SPRAYER: I mostly bottom-water seedlings, but during germination and when seedlings are tiny I mist them with this handy sprayer.
10-GALLON TRUG FOR SOIL MIXING: A 10-gallon trug or larger plastic bin is a great vessel for slightly moistening germinating mix before filling flats.
SURGE PROTECTOR TIMER: No more one timer per growlight! With 8 outlets, program multiple lights to turn on and off for the required hours per day.
HYDROFARM JUMP START T5 SYSTEM: One 4-foot T5 high output bulb on an adjustable super-lightweight frame= can accommodate two flats. (2-foot size also.)
JOHNNY'S 512 MIX: I've ordered this for germinating purposes for years. Has organic nutrients (fishmeal, not chemicals) added. Works for soil-blocking, too.
SEEDLING GERMINATING MAT: I use single tray-sized mats (approx. 8.5x18.5"), but mats also come in double-wide or double-long (for 2 trays), and up to 5-foot-long pro versions.
LADBROOKE SOIL BLOCKERS: Many experts swear by soil blocking (as opposed to sowing in cells or open flats without blocks). The tools for making blocks, in various sizes. Note: The mix you use must be rated for blocking.
NITRILE-COATED GARDEN GLOVES: I like mine black, and by Atlas or Bellingham. I eventually poke through the right hand middle finger from digging with my hands...but other than that they'd last a long time.
PULLEY HARDWARE FOR GROWLIGHT: To hang and adjust your hood, you'll need to rig S-hooks and chain, or even easier pulley with store-bought hardware. (Shown: Vivosun brand.)