A thick green row of seedlings filled my back raised bed last spring, all from one pinch of seed I planted a quarter inch (0.6 cm) deep and kept watered. No, cilantro from seed is not hard. The plant practically does the work for you once the seed sits in moist ground. I barely touched that row after sowing it, and it still came up dense enough to thin twice.
A month before that row went in, I had a sad tray of cilantro starts on the windowsill. I moved them into the same bed and watched every one wilt and stall within a week. I pulled the dead stems out and scattered fresh seed in the gaps instead. Those scattered seeds outran the transplants without any fuss at all, and they did it in cooler, wetter soil than the starts ever got.
Here is the one catch you have to know. Cilantro grows a long taproot that does not want to be moved. When you direct sow cilantro right where it will grow, that root drives straight down and the plant takes off. Dig it up to transplant and you break or bend that root, which checks the plant or kills it outright. This is why nursery starts often disappoint. The damage happens out of sight, below the soil, so the plant looks fine for a day or two and then quits. Seeds dodge the whole problem because nothing ever moves them.
So skip the trays. Good cilantro seed germination comes down to depth and water more than anything else. Sow your seeds a quarter to half inch (0.6 to 1.3 cm) deep in the spot you want them. Keep your soil steady and moist, not soggy, until the green shows. Dry ground is the main reason your seeds stall, so check it daily in warm weather and water when the top feels dry to your finger.
One trick speeds things up for you. Each round cilantro seed is really a husk holding two seeds inside. Gently crush the husks between your fingers or under a board before you sow, and water soaks in faster. That can shave a few days off your wait for sprouts.
Press the round seed husks lightly to split them so water reaches the seed inside faster.
Plant a quarter to half inch (0.6 to 1.3 cm) deep right where the cilantro will grow, never in a tray to move later.
Water often enough that the top of the soil stays damp until seedlings appear in one to two weeks.
Pull the weakest sprouts so the keepers stand six to eight inches (15 to 20 cm) apart with room to bush out.
Timing matters as much as depth. Cilantro likes cool weather and bolts fast in heat, so sow in early spring or fall when days run mild. Hot summer sun pushes it to flower before you get many leaves, and once it bolts the flavor turns sharp and the leaves go thin and ferny. A spot with afternoon shade buys you a longer harvest in warmer zones. Cool soil also helps the seeds wake up, since they germinate best when the ground sits between 55°F and 68°F (13°C and 20°C).
Thinning feels harsh but it pays off for you. Crowded plants stay small and weak, while a thinned row gives you full, leafy stems. Snip the sprouts you pull and toss them in a salad so nothing goes to waste. Once you grow cilantro from seed this way, you will not bother with starts again.
The smartest habit with cilantro is to keep planting cilantro seeds every two to four weeks through the cool season. Each plant has a short window before it bolts, so a steady stream of small sowings beats one big patch. This rolling schedule keeps fresh leaves on hand far better than fussing with indoor trays you would only have to skip anyway.
Read the full article: Cilantro Plant: Complete Growing Guide
