Best Time To Plant Lavender In Colorado

Colorado’s high altitude and dry conditions require planting lavender in late spring after the snow melts completely. If you want a thriving lavender patch, the best time to plant lavender in Colorado is between mid-May and early June, once the soil has warmed up and the risk of frost has passed. This timing gives your plants the longest growing season while avoiding the stress of sudden cold snaps.

Lavender loves Colorado’s sunny days and well-draining soil, but it hates wet feet and freezing temperatures. Getting the planting window right is the most important step for success. Here’s everything you need to know about timing, preparation, and care.

The exact date varies by elevation and microclimate, but the general rule is simple: wait until nighttime temperatures stay above 50°F (10°C) consistently. In Denver and the Front Range, this usually happens around mid-May. In higher elevations like Colorado Springs or Boulder, you might need to wait until early June. In warmer areas like Grand Junction, late April or early May can work.

Why this timing? Lavender is a Mediterranean plant that thrives in heat and dry conditions. Planting too early, when the soil is still cold and wet, can cause root rot. Planting too late, in the heat of July, stresses the plant because it hasn’t had time to establish roots before the intense summer sun hits.

Check Your Local Frost Dates

Colorado’s weather is famously unpredictable. A late spring snowstorm can dump six inches in May. To be safe, check your area’s average last frost date. For most of Colorado, that’s between May 10 and May 25. Wait at least one week after that date to plant.

You can find your specific frost date by searching your county’s extension office website. They have localized data that’s more accurate than generic online charts.

Soil Temperature Matters More Than Air Temperature

Lavender roots need soil temperatures above 60°F (15°C) to grow actively. Use a soil thermometer to check. If the soil feels cold to the touch, wait. Cold soil slows root development and encourages fungal diseases.

To warm the soil faster, you can cover your planting area with black plastic for a week before planting. This simple trick can raise soil temperature by 5-10 degrees.

Choosing The Right Lavender Variety For Colorado

Not all lavender is created equal. Some varieties handle Colorado’s harsh conditions better than others. English lavender (Lavandula angustifolia) is the most reliable choice. It’s hardy to Zone 5, which covers most of Colorado. Popular varieties include ‘Munstead’, ‘Hidcote’, and ‘Lady’.

French lavender (Lavandula stoechas) is not cold-hardy enough for Colorado winters. It might survive in a protected spot in the warmest parts of the state, but it’s risky. Stick with English or lavandin (Lavandula x intermedia) varieties like ‘Grosso’ or ‘Provence’ for better cold tolerance.

Consider Your Elevation

If you live above 7,000 feet, your growing season is shorter and your winters are colder. Look for varieties specifically bred for high altitudes. ‘Phenomenal’ lavender is a newer hybrid that handles cold, humidity, and poor soil better than most. It’s an excellent choice for mountain gardeners.

At lower elevations, you have more options. ‘Munstead’ and ‘Hidcote’ are tried-and-true performers in Denver and the Front Range.

Preparing Your Soil For Lavender

Lavender demands well-draining soil. Colorado’s clay-heavy native soil holds too much moisture, which kills lavender roots. You must amend the soil before planting. Here’s a step-by-step guide:

Choose a spot with full sun—at least 6-8 hours of direct sunlight daily.
Dig a hole twice as wide as the pot but no deeper. Lavender likes its roots near the surface.
Mix the native soil with coarse sand or gravel at a 50/50 ratio. This improves drainage dramatically.
Add a small amount of compost—no more than 10% of the mix. Too much organic matter retains moisture.
Test drainage by filling the hole with water. It should drain completely within 30 minutes. If it doesn’t, add more sand or gravel.

Raised beds are ideal for lavender in Colorado. They warm up faster in spring and drain better than ground soil. If you have heavy clay, build a raised bed at least 12 inches tall.

Adjust Soil PH

Lavender prefers slightly alkaline soil with a pH between 6.5 and 7.5. Colorado’s soil is often alkaline already, so you usually don’t need to adjust. But if your soil is acidic, add a little garden lime to raise the pH. Test your soil before planting to be sure.

Step-By-Step Planting Instructions

Once the timing is right and your soil is prepared, follow these steps for planting lavender in Colorado:

Water the lavender plant in its pot thoroughly an hour before planting.
Remove the plant from the pot gently. Loosen any circling roots with your fingers.
Place the plant in the hole so the top of the root ball is level with the soil surface. Planting too deep is a common mistake.
Backfill with your amended soil mix, pressing lightly to remove air pockets.
Water deeply right after planting to settle the soil.
Space plants 18-24 inches apart for good air circulation. Lavender hates crowding.

Do not add mulch around lavender. Mulch retains moisture, which can cause stem rot. Instead, leave the soil bare or use a thin layer of gravel or pebbles. This reflects heat and keeps the crown dry.

Watering After Planting

For the first two weeks, water your lavender every 2-3 days if there’s no rain. After that, gradually reduce watering. Once established, lavender is drought-tolerant and only needs water every 7-10 days during dry spells. Overwatering is the fastest way to kill lavender in Colorado.

Water at the base of the plant, not overhead. Wet leaves invite fungal diseases. Use a soaker hose or drip irrigation for best results.

Caring For Lavender Through Colorado’s Seasons

Lavender care changes with the seasons. Here’s what to do throughout the year:

Spring Care

Prune dead wood from the previous year once new growth appears.
Do not fertilize. Lavender thrives in lean soil. Fertilizer encourages leafy growth that is less hardy.
Check drainage after winter snow melts. Add sand if water pools around the plants.

Summer Care

Water deeply but infrequently. Let the soil dry out between waterings.
Harvest flowers when they are about half open for the best fragrance.
Deadhead spent blooms to encourage a second flush in late summer.

Fall Care

Stop watering in September to help plants harden off for winter.
Do not prune in fall. Leave the foliage to protect the crown from cold.
Apply a 2-inch layer of gravel or coarse sand around the base for winter insulation.

Winter Care

In colder areas (Zone 4 or lower), cover plants with a frost blanket or row cover during extreme cold snaps.
Do not use plastic covers, which trap moisture and cause rot.
Remove heavy snow from branches to prevent breakage.

Common Mistakes When Planting Lavender In Colorado

Even experienced gardeners make these errors. Avoid them for a healthier lavender patch:

Planting too early. Cold, wet soil kills roots. Wait for warm soil.
Planting too deep. The crown should be at or slightly above soil level.
Overwatering. Lavender is a desert plant. Less water is better.
Using rich soil or compost. Lavender needs poor, gritty soil.
Ignoring drainage. If water doesn’t drain fast, lavender dies.
Planting in shade. Lavender needs full sun to thrive and bloom.

Growing Lavender In Containers In Colorado

If your soil is impossible to amend, or if you want to move plants indoors during winter, containers are a great option. Use a pot with drainage holes at least 12 inches wide. Fill with a cactus or succulent potting mix, which drains quickly.

Container lavender needs more frequent watering than in-ground plants, but still let the soil dry out between waterings. In winter, move containers to an unheated garage or shed where temperatures stay above freezing but below 50°F. Water sparingly—only when the soil is completely dry.

Propagating Lavender From Cuttings

If you want more lavender plants without buying new ones, take cuttings in late spring or early summer. Here’s how:

Cut a 4-inch stem from a healthy plant, just below a leaf node.
Remove the lower leaves, leaving only the top few.
Dip the cut end in rooting hormone powder (optional but helpful).
Insert the cutting into a pot filled with moistened sand or perlite.
Cover with a plastic bag to create humidity. Place in bright, indirect light.
Roots should form in 3-4 weeks. Transplant to a larger pot after that.

This method works well for English lavender varieties. It’s a cost-effective way to fill a garden bed.

Harvesting And Using Lavender

Harvest lavender in the morning after the dew dries but before the heat of the day. Cut stems when about half the flowers on a spike have opened. This is when the oil content is highest.

Bundle 10-15 stems together with a rubber band and hang them upside down in a dark, dry, well-ventilated area. They’ll dry in 2-4 weeks. Once dry, strip the flowers from the stems and store in an airtight jar.

Use dried lavender for sachets, potpourri, culinary recipes, or homemade soaps. The flowers retain their fragrance for up to a year if stored properly.

Dealing With Pests And Diseases

Lavender is naturally pest-resistant, but a few issues can arise in Colorado:

Root rot: Caused by overwatering or poor drainage. Prevent by planting in well-draining soil and watering sparingly.
Whiteflies: Rare but possible in hot, dry conditions. Spray with a strong stream of water or use insecticidal soap.
Spittlebugs: Look like white foam on stems. They rarely cause serious damage. Wash them off with water.
Fungal leaf spot: Occurs in humid conditions or with overhead watering. Improve air circulation and water at the base.

Healthy lavender plants resist most problems. Focus on proper planting and watering, and you’ll rarely need to treat for pests.

Frequently Asked Questions

Can I plant lavender in fall in Colorado?

Fall planting is risky in Colorado. The plants won’t have enough time to establish roots before winter. If you must plant in fall, do it at least 6 weeks before the first frost, and provide winter protection. Spring planting is much more reliable.

How long does lavender take to grow in Colorado?

Lavender grows slowly in its first year. You’ll see modest growth and maybe a few flowers. By the second year, plants double in size and produce a good bloom. Full maturity takes 3-4 years.

Do I need to cover lavender in winter in Colorado?

In Zone 5 and warmer, lavender usually survives winter without cover. In Zone 4 or colder, cover with a frost blanket or evergreen boughs. Do not use plastic or heavy mulch, which cause rot.

What is the best lavender for Colorado’s high altitude?

‘Phenomenal’ lavender is the top choice for high altitudes. It’s hardy to Zone 4 and handles cold, wind, and poor soil. ‘Munstead’ and ‘Hidcote’ also perform well in most Colorado locations.

How often should I water lavender in Colorado?

After establishment, water deeply every 7-10 days during dry periods. In rainy weather, don’t water at all. Lavender prefers dry soil to wet soil. Overwatering is the most common cause of death.

Final Tips For Success

Planting lavender at the right time is half the battle. The other half is giving it the poor, dry, sunny conditions it craves. Colorado’s climate is actually ideal for lavender if you work with it, not against it.

Start with a small patch. Lavender is forgiving if you get the basics right. Once you see how well it grows, you’ll want more. The bees and butterflies will thank you, and your garden will smell amazing all summer long.

Remember: late spring, full sun, fast-draining soil, and minimal water. Follow these rules, and your lavender will thrive in Colorado’s unique environment.