How to Grow Cimmaron Romaine Lettuce From Seed

Cimmaron is a red-tinged romaine lettuce with upright leaves and crisp ribs. It can be harvested young for salad leaves or left to form a fuller romaine plant. Plan for cool weather, give each plant room, and keep water consistent while the center develops.

Cimmaron Romaine Lettuce Seeds

Choose the romaine harvest you want

Cimmaron combines the upright structure of romaine with red or bronze coloring over green leaves. The amount of color varies with growing conditions. Expect a romaine plant rather than a dense, round iceberg head. The crisp central ribs are a useful clue to its type.

For baby leaves, sow a small patch and harvest it early. For larger romaine plants, start in rows or cells and thin to 10–12 inches. Trying to grow full plants at baby-leaf density leads to crowding and makes the center harder to inspect.

Work backward from cool harvest weather

In many places, sow in early spring or late summer for fall. Warm-winter gardeners may have their best results in fall and winter. Allow the packet’s 55–70 day estimate while recognizing that weather and harvest size change the actual date.

Heat and long days can encourage flowering, even in a variety described as slow to bolt. Morning sun and some afternoon shade may help during the shoulder season, but no lettuce stays in prime condition indefinitely. Our Parris Island romaine guide provides a useful comparison with a green romaine.

Sow shallowly and establish uncrowded plants

Prepare a fine seedbed and sow about ⅛–¼ inch deep with a light covering. Keep the seed zone moist using a gentle spray. If soil is too warm for good emergence, start cells in a cooler bright place and transplant young seedlings when conditions improve.

Thin promptly to the spacing needed for your goal. Harden indoor seedlings gradually and plant them at the same depth as in their cells. Water the root ball into the surrounding soil. Keep the growing point above ground instead of mounding soil into the center.

Support crisp growth with even moisture

Check the root zone often enough to prevent repeated wilting. Water thoroughly when needed and let the soil drain. A thin mulch between established plants can slow evaporation, but damp material should not be packed against the crowns.

Feed according to a soil test or the needs of the potting mix. Excess nitrogen does not fix heat stress, and fertilizer salts can become a problem in a repeatedly dried-out container. Our lettuce watering guide explains practical moisture checks.

Watch the center as the plant fills

Inspect the folded inner leaves for aphids and developing brown edges. Leaf-tip browning can have physiological causes and is not automatically a fungus. Keep irrigation steady and examine the pattern before deciding on treatment. Ragged holes suggest a different problem, such as slugs or chewing insects.

Good spacing makes these checks easier. If the center starts stretching into a tall stem, the plant is moving toward flowering. Do not wait for it to become a large decorative tower if your purpose is tender salad leaves.

Harvest young leaves or a whole romaine

For repeated picking, remove a few mature outer leaves and preserve the central growing point. For a whole plant, cut at the base when the upright center has filled to the size and firmness you prefer. You do not need to wait for the tightness of a supermarket-trimmed romaine heart.

Cool the harvest promptly and rinse before use. A container at least about 8–10 inches deep can work if plants have room and water drains freely. Sow a small replacement group while the first planting is still useful so the next harvest does not depend on an aging, bolting plant.

Growing questions

Are Cimmaron and Cimarron different names?

Both spellings are used for this romaine type. This guide follows the Cimmaron spelling on the Gardeners Basics product.

Why is the center greener than the outer leaves?

Newer, shaded leaves can show less red coloring. Evaluate the whole plant’s health rather than treating the green center alone as a problem.

Do I need to tie the leaves together?

No. Grow the plant naturally and harvest at the size you want. Tying is not necessary to produce a useful romaine crop.

Ready for another planting? See Cimmaron Romaine Lettuce Seeds for the current packet options.