Learn About Lemongrass

Posted in: Other Herbs
Learn About Lemongrass

How To Sow    How To Grow    Tips    Common Pests    FAQ

How to Sow and Plant

Sowing Directly in the Garden:

  • Sow in full sun in average soil after danger of frost in spring.
  • Remove weeds and work organic matter into the top 6-8 inches of soil; then level and smooth. 
  • Sow seeds evenly and thinly and barely cover with fine soil.
  • Firm lightly and keep evenly moist.
  • Seedlings emerge in 14-21 days.
  • Thin or transplant shipped plants to 12 inch apart when seedlings are 1-2 inches tall.

Planting Potted Plants in the Garden:

  • Select a location in full sun with average soil.
  • Prepare the bed by turning the soil under to a depth of 8 inches. Level with a rake to remove clumps of grass and stones.
  • Dig a hole for each plant large enough to amply accommodate the root ball.
  • Carefully remove the plant from its pot and gently loosen the root ball with your hands to encourage good root development.
  • Place the top of the root ball even with the level of the surrounding soil. Fill with soil to the top of the root ball. Press soil down firmly with your hand.
  • Use the plant tag as a location marker.
  • Thoroughly water and apply a light mulch layer on top of the soil (1-2 inches) to conserve water and reduce weeds.

How to Grow

  • Mulches also help retain soil moisture and maintain even soil temperatures. For herbs, an organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
  • Keep plants well-watered during the growing season, especially during dry spells. Plants need about 1 inch of rain per week during the growing season. Use a rain gauge to check to see if you need to add water. It’s best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
  • Fertilize regularly with an all purpose fertilizer.
  • Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.

Harvest and Preserving Tips

  • Harvest leafy tops when they are about 10-12 inches tall. The leaves may be used to flavor teas and soups.
  • Collect stalks at the end of the season before frost when they are about a half inch in diameter.
  • Snap stalks off at their base. Only the bottom of the stalk is edible.
  • Use the inner part of the stalk, slice into rings or strips and bruise segments to release their flavor.
  • Chopped pieces of stalk may be frozen in ice cube trays for future use.
  • Lemongrass may be dried for storage. Place stalks in a 120 degree F oven for 2-3 hours, with the oven door cracked open. Check to make sure the stalks are not getting singed.

Common Disease Problems

Blight: Early Blight is a very common disease which causes brown concentric rings to appear on the lower leaves. The spots coalesce; the leaf turns brown and may drop off the stem. Leaf drop moves up the stem. This fungus overwinters in plant debris and weeds. Late blight is another fungus disease that causes defoliation and fruit rot. Greasy, greenish-black, water soaked spots appear on the lower leaves. The spots enlarge and if the weather is wet they will look mildewed. Rainy or cloudy days with temperatures of 70-80 degrees F and nights at 40- 60 degrees F provide ideal conditions for the rapid growth of this fungus. It is retarded by hot dry weather. The fungus is air-borne and can spread from diseased plants growing nearby. Burpee Recommends: Practice good garden hygiene at the end of the season and discard, do not compost, possibly diseased plants. Space plants to allow for adequate air circulation. Avoid overhead watering which may spread fungus spores. Plant in at least a 3 year rotation, do not alternate with plants in the same family (potatoes, peppers or eggplants).

Rust: A number of fungus diseases that rust colored spots on foliage, stalks and husks. Burpee Recommends: Plant early as these diseases tend to be worse later in the season. Plant resistant varieties. Practice crop rotation. Remove infected plants.

Common Pest and Cultural Problems

Aphids: Greenish, red, black or peach colored sucking insects that can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap. .

Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.

Whitefly: These are small white flying insects that often rise up in a cloud when plants are disturbed or brushed against. Burpee Recommends: They are difficult to control without chemicals. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for pesticide recommendations.

October 29, 2021
©2023 W.Atlee Burpee & Co