Montana’s short growing season requires starting lemongrass indoors eight to ten weeks before the last expected frost. If you are searching for the best time to plant lemon grass in montana, the answer depends on your local frost dates and your willingness to start seeds indoors. Lemongrass is a tropical plant that hates cold weather, so timing is everything in a state where winter can linger into May.
This guide walks you through exactly when and how to plant lemongrass in Montana. You will learn indoor starting schedules, transplanting windows, and tips to keep your plants alive through our unpredictable seasons.
Best Time To Plant Lemon Grass In Montana
The absolute best time to plant lemon grass in montana is after the last spring frost, when soil temperatures have warmed to at least 60°F. For most of Montana, this falls between late May and early June. But you cannot just throw seeds in the ground in May and expect success. Lemongrass needs a long, warm growing season—often 100 to 120 days—which Montana’s short summers do not provide naturally.
That is why indoor starting is non-negotiable. You should start lemongrass seeds indoors about 8 to 10 weeks before your average last frost date. For example:
- If your last frost is around May 15 (Bozeman area), start seeds indoors by mid-March.
- If your last frost is around June 1 (higher elevations like Butte), start seeds indoors by late March or early April.
- If your last frost is around April 30 (eastern Montana like Miles City), start seeds indoors by late February or early March.
Check your local frost dates using the Montana USDA hardiness zone map. Most of Montana falls in zones 3 through 5, which means a short window for warm-weather crops.
Understanding Montana’s Climate For Lemongrass
Montana has a continental climate with cold winters and warm, often dry summers. Lemongrass (Cymbopogon citratus) is native to tropical regions and cannot tolerate frost. Even a light freeze will kill it. The plant thrives in temperatures between 70°F and 95°F, with high humidity—conditions that are rare in Montana.
Because of this, you must treat lemongrass as an annual or grow it in containers that you can move indoors. Many Montana gardeners grow lemongrass in pots so they can bring it inside before the first fall frost. This extends the harvest season and allows the plant to survive winter indoors.
Key Climate Factors
- Short growing season: 90 to 120 frost-free days in many areas.
- Cold soil: Soil warms slowly in spring, often not reaching 60°F until late May.
- Dry air: Low humidity can stress lemongrass, so regular misting or grouping plants helps.
- Strong winds: Montana’s wind can dry out soil and damage tender leaves. Use windbreaks or sheltered spots.
Step-By-Step Guide To Starting Lemongrass Indoors
Starting lemongrass indoors is the most reliable way to get a head start. Here is how to do it:
- Choose your seeds or starts. Lemongrass is often grown from stalks purchased at grocery stores, but seeds are also available. For Montana, seeds are more reliable because they are less likely to carry diseases.
- Soak seeds overnight. Lemongrass seeds have a hard coat. Soaking them in warm water for 12 to 24 hours improves germination.
- Use seed-starting mix. Fill small pots or seed trays with a light, well-draining mix. Moisten it before planting.
- Plant seeds shallow. Press seeds into the soil surface and cover lightly with a thin layer of mix. They need light to germinate.
- Provide warmth. Lemongrass seeds germinate best at 70°F to 80°F. Use a heat mat if your home is cool.
- Keep soil moist. Cover pots with plastic wrap or a humidity dome to retain moisture. Remove once seedlings appear.
- Provide light. Place seedlings under grow lights or in a bright south-facing window. They need 12 to 14 hours of light daily.
- Harden off before transplanting. About a week before moving outdoors, gradually expose plants to outdoor conditions. Start with a few hours of shade, then increase time and sunlight.
Germination takes 7 to 14 days. Once seedlings have two sets of true leaves, you can transplant them into larger pots if needed.
Transplanting Lemongrass Outdoors In Montana
Transplant lemongrass outdoors only after all danger of frost has passed and soil temperatures are consistently above 60°F. In most of Montana, this means late May to early June. But do not rely solely on the calendar. Use a soil thermometer to check the temperature at a depth of 4 inches.
Here is a checklist for successful transplanting:
- Choose a sunny location with at least 6 to 8 hours of direct sunlight.
- Prepare the soil by mixing in compost or aged manure. Lemongrass prefers rich, well-draining soil with a pH between 6.0 and 7.5.
- Space plants 24 to 36 inches apart. Lemongrass grows into large clumps.
- Water deeply after transplanting. Keep soil consistently moist but not waterlogged.
- Mulch around plants to retain moisture and suppress weeds. Use straw or wood chips.
- Consider using row covers or cloches if a late frost threatens. Protect plants overnight.
If you are growing lemongrass in containers, you can move them outdoors after frost and bring them inside before the first fall frost. This gives you more control over the growing environment.
Caring For Lemongrass During Montana Summers
Once established, lemongrass requires regular care to thrive in Montana’s dry climate. Here are the main tasks:
Watering
Lemongrass needs consistent moisture. Water deeply once or twice a week, more often during hot, dry spells. Check soil moisture by sticking your finger an inch into the soil. If it feels dry, water. Avoid overhead watering to prevent fungal diseases. Use drip irrigation or water at the base.
Fertilizing
Feed lemongrass every 4 to 6 weeks with a balanced fertilizer (10-10-10) or a nitrogen-rich organic option like fish emulsion. Stop fertilizing by late summer to allow the plant to slow down before fall.
Pruning
Remove dead or yellowing leaves throughout the season. This improves air circulation and reduces disease risk. You can also harvest stalks by cutting them at the base once they are about 12 inches tall.
Pest And Disease Management
In Montana, common pests include aphids, spider mites, and grasshoppers. Use insecticidal soap for aphids and mites. For grasshoppers, use row covers or diatomaceous earth. Fungal diseases are rare in dry climates but can occur with overwatering. Ensure good drainage and avoid wetting leaves.
Harvesting Lemongrass In Montana
You can start harvesting lemongrass about 90 to 120 days after planting, depending on the variety and weather. In Montana, this usually means late August to early September. Harvest stalks when they are at least 12 inches tall and about half an inch thick at the base.
To harvest:
- Cut stalks at ground level using sharp shears.
- Remove the tough outer leaves and the green tops (save these for tea or compost).
- Use the tender white base for cooking or drying.
If you plan to overwinter lemongrass indoors, stop harvesting by late September to allow the plant to store energy. Dig up the entire clump before the first frost, pot it, and bring it inside.
Overwintering Lemongrass Indoors
Lemongrass is a perennial in warm climates, but in Montana, it must be overwintered indoors. Here is how:
- Before the first frost (usually late September to early October), dig up the entire clump.
- Trim leaves to about 6 inches tall.
- Pot the clump in a container with drainage holes, using fresh potting soil.
- Place in a bright, sunny window or under grow lights.
- Water sparingly during winter—only when the soil feels dry to the touch.
- Keep temperatures above 50°F. A cool basement or garage works if it stays above freezing.
- In spring, gradually reintroduce the plant to outdoor conditions after the last frost.
Alternatively, you can take cuttings from the stalks and root them in water. This is a good way to propagate new plants for the next season.
Common Mistakes When Planting Lemongrass In Montana
Even experienced gardeners make mistakes. Here are the most common ones and how to avoid them:
- Planting too early. Do not rush to transplant outdoors. A late frost can kill young plants. Wait until soil is warm and frost is no longer a risk.
- Overwatering. Lemongrass likes moisture but not soggy soil. Poor drainage leads to root rot.
- Underwatering. Montana’s dry air and wind can dry out soil quickly. Check moisture daily during hot spells.
- Ignoring wind. Strong winds can damage leaves and dry out plants. Use windbreaks or plant near a fence or wall.
- Not hardening off. Sudden exposure to sun and wind can shock indoor-started plants. Always harden off gradually.
- Forgetting to overwinter. If you want lemongrass to survive, you must bring it indoors before frost. Do not assume it will come back in spring.
Best Varieties Of Lemongrass For Montana
Not all lemongrass varieties are equal. Some are more cold-tolerant or faster-growing. For Montana, choose varieties that mature quickly and handle cooler temperatures better:
- East Indian Lemongrass (Cymbopogon flexuosus): This variety grows faster and is more cold-tolerant than West Indian types. It is the best choice for short seasons.
- West Indian Lemongrass (Cymbopogon citratus): Common in grocery stores, but slower to mature. It works if you start early indoors.
- Citronella (Cymbopogon nardus): Often grown for mosquito repellent. It is similar in care but less flavorful for cooking.
Stick with East Indian lemongrass for the best results in Montana. It matures in about 90 days, giving you a better chance of a harvest before frost.
Frequently Asked Questions
Can I plant lemongrass seeds directly in the ground in Montana?
It is not recommended. Montana’s soil warms slowly, and direct-sown seeds may not germinate or grow enough before frost. Always start seeds indoors for reliable results.
What is the latest I can plant lemongrass in Montana?
If you are transplanting from indoor starts, the latest safe date is early June. Planting later than that reduces your harvest window. For seeds, start indoors no later than early April.
Does lemongrass survive winter in Montana?
No. Lemongrass cannot survive Montana’s freezing winters outdoors. You must overwinter it indoors or treat it as an annual. Some gardeners have success in unheated garages if temperatures stay above 40°F.
How do I know when to start lemongrass seeds indoors?
Count back 8 to 10 weeks from your average last frost date. For most of Montana, that is mid-March to early April. Use online frost date calculators for your specific town.
Can I grow lemongrass in a container in Montana?
Yes, containers are ideal. They allow you to move the plant indoors for winter and control soil conditions. Use a pot at least 12 inches deep and wide, with drainage holes.
Final Tips For Success
Growing lemongrass in Montana is possible with careful planning. Start seeds indoors early, transplant after frost, and provide consistent care. Remember that the best time to plant lemon grass in montana is late spring, but the real secret is starting indoors weeks before. With a little effort, you can enjoy fresh lemongrass for teas, curries, and stir-fries even in our short summers.
Keep an eye on weather forecasts in spring and fall. A sudden cold snap can ruin your plants. Use frost cloth or bring containers inside if temperatures drop unexpectedly. And do not be afraid to experiment. Each season teaches you something new about your local microclimate.
If you follow these steps, you will have a healthy lemongrass patch that provides fresh stalks from summer through fall. And with proper overwintering, you can enjoy it year after year.