Purple love grass grows from seed in 7 to 10 days and reaches full size in 60 to 90 days

Purple love grass (Eragrostis spectabilis) is an ornamental grass that produces delicate, purple-tinged seed heads in late summer. You can start it from seed indoors 6 to 8 weeks before your last frost date, or direct sow it into the ground after frost danger has passed. The seeds are tiny and need light to germinate, so you press them into soil rather than cover them—burying them will prevent sprouting.

The grass tolerates poor soil, drought, and full sun once established, which makes it a low-maintenance choice for borders, containers, or meadow plantings. Starting from seed is inexpensive and gives you many plants from a single packet.

Key Takeaways

  • Purple love grass seeds need light to germinate, so press them onto moist soil and do not cover them with soil or mulch.
  • Indoors, seeds sprout in 7 to 10 days under consistent moisture and temperatures between 65 and 75 degrees Fahrenheit.
  • Seedlings are ready to transplant outdoors when they have two to three true leaves, usually 4 to 6 weeks after sowing.
  • Direct sowing outdoors works in spring after the last frost date; scatter seeds on prepared soil, press them down, and keep the area moist until sprouting.
  • Once established, purple love grass needs water only during extended drought and thrives in full sun with minimal fertilizer.

Starting seeds indoors under lights

Fill a seed tray or shallow container with seed-starting mix—a sterile blend of peat moss, coconut coir, and perlite that drains well and holds moisture evenly. Moisten the mix thoroughly before you sow. Scatter the tiny purple love grass seeds across the surface and press them gently into the soil with your fingertip or the back of a spoon. Do not cover them. Mist the surface lightly with a spray bottle to settle the seeds.

Place the tray under grow lights or on a sunny windowsill where it receives at least 12 hours of light daily. Keep the soil moist but not waterlogged—check it daily and mist if the surface begins to dry. Maintain temperatures between 65 and 75 degrees Fahrenheit. Germination occurs in 7 to 10 days. Once seedlings emerge, continue the light and moisture routine; they will grow quickly.

When seedlings have two to three true leaves (the second and third leaves that appear after the initial seed leaves), they are ready to thin or transplant. If they are crowded, snip away the weaker seedlings with scissors rather than pulling them out, which can disturb roots of neighbors. Space remaining seedlings about 1 inch apart in the tray, or transplant them into individual small pots filled with potting soil.

Hardening off and moving seedlings outdoors

Before transplanting seedlings into the garden, they need to adjust to outdoor conditions—wind, direct sun, and temperature swings. This process, called hardening off, takes 7 to 10 days. Begin by placing the tray in a sheltered, shaded spot outdoors for 1 to 2 hours. Each day, increase the time outdoors and gradually move the tray into brighter light. By the end of the period, seedlings should tolerate full sun and outdoor temperatures.

Harden off only after your last spring frost date has passed and nighttime temperatures stay above 50 degrees Fahrenheit. Purple love grass is not frost-hardy as a seedling, though mature plants tolerate cold better.

Transplanting into the garden

Choose a location with full sun—at least 6 hours of direct light daily—and soil that drains well. Purple love grass tolerates poor, sandy, or clay soil and does not need rich amendments. Dig a hole slightly larger than the root ball of each seedling, set the plant at the same depth it was growing in its pot, and firm the soil around it. Space plants 12 to 18 inches apart, depending on the mature size you want; closer spacing creates a denser planting.

Water the newly planted seedlings regularly for the first 2 to 3 weeks while they establish roots. Once established, purple love grass is drought-tolerant and needs water only during extended dry spells. Do not fertilize; excess nitrogen causes weak, floppy growth and reduces the intensity of the purple seed head color.

Direct sowing seeds outdoors

If you prefer to skip the indoor step, you can sow purple love grass directly into the garden after the last frost date. Prepare the soil by removing weeds and breaking up compacted areas. Scatter seeds thinly across the prepared bed and press them into the soil with your hand or a board. Do not rake or cover them. Mist the area lightly with a hose or spray bottle to settle the seeds and moisten the soil.

Keep the seeded area moist for the first 2 to 3 weeks while seeds germinate and seedlings establish. Once seedlings are 2 to 3 inches tall, thin them to 12 to 18 inches apart by snipping away the weaker plants. Direct sowing produces results more slowly than transplanting seedlings—you will see flowering plants in late summer of the same year, but they will be smaller than transplants.

Watering and care during the growing season

Water newly planted seedlings or direct-sown areas consistently until plants are established, usually 3 to 4 weeks. After that, purple love grass is very drought-tolerant and needs supplemental water only during extended periods without rain—more than 2 to 3 weeks in hot weather. Overwatering causes root rot and weak growth.

The grass does not need staking or support even in wind. Avoid fertilizing; the plant thrives in poor soil and fertilizer encourages leafy growth at the expense of the ornamental seed heads. If you see weeds competing with seedlings, pull them by hand or use a hoe carefully to avoid disturbing the young grass.

Harvesting seed heads and overwintering

Purple love grass produces its distinctive purple-pink seed heads in late summer and early fall. You can cut the stems for dried arrangements once the color is fully developed. Leave some seed heads on the plant if you want it to self-seed in the garden next year—the grass will drop seeds naturally, and many will sprout in spring.

In cold climates (zones 5 and colder), cut back the entire plant to 3 to 4 inches tall in late fall or early spring before new growth begins. In warmer zones (6 and above), you can leave the dried foliage standing through winter for visual interest and cut it back in spring. The plant will regrow from the base each year.

Frequently Asked Questions

Do I need to soak or scarify purple love grass seeds before planting?

No. The seeds have a thin coat and do not need soaking or scarification. They germinate reliably when pressed onto moist soil and exposed to light. Soaking can actually reduce germination rates.

Can I direct sow in fall instead of spring?

Direct sowing in fall is risky in most climates because seeds may germinate in warm spells, then be killed by frost. Spring sowing after the last frost date is more reliable. If you live in a warm zone where winter temperatures rarely drop below 40 degrees, fall sowing is possible but not necessary.

Why are my seedlings tall and spindly?

Spindly seedlings usually mean insufficient light. Move the tray closer to grow lights or a sunny window so seedlings receive at least 12 hours of bright light daily. You can also lower the lights as seedlings grow. Temperatures above 75 degrees also encourage stretching.

How long does it take to see the purple seed heads?

Seedlings transplanted outdoors in spring will produce seed heads in late summer or early fall of the same year, usually 60 to 90 days after transplanting. Direct-sown seeds germinate later and may produce smaller seed heads the first year, with full-sized heads in year two.

Is purple love grass invasive?

Purple love grass self-seeds readily but is not considered invasive in most regions. It spreads by seed, not by runners, so you can control it by deadheading before seeds drop or by pulling unwanted seedlings. In some warm, dry regions it may spread more aggressively, so check your local extension office if you are concerned.