How To Grow And Care For Alstroemeria

Alstroemeria, also known as the Peruvian Lily or Lily of the Incas, belongs to the Alstroemeriaceae family and is native to South America, particularly the Andes region from Venezuela to Chile. These herbaceous perennial plants grow from tuberous roots and feature lance-shaped leaves that can be variegated.

Their trumpet-shaped flowers come in vibrant colors with unique markings, making them popular ornamentals in gardens and prized cut flowers in the floristry industry. While not endangered in the wild, some Alstroemeria species face threats due to habitat loss and illegal harvesting.

Interesting Facts

• Symbolism: Symbolizes friendship, love, strength, and devotion.
• Diversity: Over 50 species are recognized, with numerous hybrids and cultivars.
• Longevity: Flowers can last up to two weeks in a vase.
• Pests: Generally resistant to pests and diseases.

Alstroemeria offer a variety of cultivars that appeal to gardeners and florists alike. Here are some popular choices:

• 'Princess Lilies' (Alstroemeria princess lilies): Known for their compact growth and vibrant colors, they are ideal for containers and small gardens.
• 'Inticancha' Series: Compact and floriferous, perfect for borders or patio pots, offering a range of colors from soft pastels to bright hues.
• 'Peruvian Parrot' (Alstroemeria psittacina): Features unique spotted and striped petals resembling parrot feathers, adding an exotic flair to gardens.
• 'Moulin Rouge': Bright and vibrant orange and yellow hues that shine in both the summer garden and floral arrangements. It reaches a maximum height of approximately 28 inches

Choosing the Correct Variety to Grow

When selecting an Alstroemeria variety to grow, consider the following factors:

• Climate Compatibility: Choose varieties that thrive in your local climate, considering factors like temperature, humidity, and frost tolerance.
• Growth Habit: Determine if you prefer compact varieties suitable for containers or taller types for borders and cutting gardens.
• Flower Characteristics: Select based on flower size, color palette (solid or variegated), and petal shape to suit your aesthetic preferences or floral arrangement needs.
• Maintenance Needs: Consider the maintenance level required, such as pruning, deadheading, and fertilization, to ensure it fits with your gardening schedule and expertise.

By matching the variety's characteristics to your gardening goals and local conditions, you can ensure successful cultivation and enjoyment of Alstroemeria in your garden or floral displays.

When planting Alstroemeria, follow these steps for successful growth:

Choosing the Right Location

• Sunlight: Alstroemeria thrives in full sun to partial shade. In hotter climates, they benefit from some afternoon shade to prevent overheating.
• Soil: These plants prefer well-drained, fertile soil rich in organic matter. A slightly acidic to neutral pH (6.0 to 7.0) is ideal.

Planting Time

Alstroemerias are typically planted in spring after the last frost date for your area. This timing allows the plants to establish themselves during the warmer months. Here are some key points to consider regarding planting time for Alstroemeria:

• Spring Planting: Aim to plant Alstroemerias in early to mid-spring once the soil has warmed up and there is no longer a risk of frost. This timing promotes strong root development before the heat of summer.
• Climate Considerations: In colder climates, it's essential to wait until all danger of frost has passed before planting. Alstroemerias are sensitive to frost and should not be planted outdoors until temperatures are consistently mild.
• Warm Soil: Alstroemerias prefer soil that has warmed to around 60°F (15°C) or more for optimal growth. Cold, damp soil can delay root establishment and potentially harm the tubers.
• Fall Planting: In regions with mild winters and cooler summers, fall planting can also be successful. Planting in early fall allows the roots to establish before winter dormancy sets in.
• Container Planting: Alstroemerias can also be planted in containers any time the soil is workable, but ensure containers have adequate drainage to prevent waterlogging.

Planting Depth and Spacing

When planting Alstroemeria, it's important to consider the appropriate depth and spacing for optimal growth:

Planting Depth

• Dig a hole that is slightly larger than the root ball or tuber of the Alstroemeria plant.
• Plant the tubers about 4-6 inches deep into the soil.
• Ensure that the top of the tuber is just below the soil surface to protect it from frost and encourage strong root development.

Spacing

• Space Alstroemeria tubers about 12-24 inches apart.
• This spacing allows enough room for the plants to spread and grow without overcrowding.
• Proper spacing also facilitates good air circulation around the plants, which helps prevent diseases and promotes healthy foliage and flowering.

Growing Alstroemeria from seed is not commonly practiced due to low germination rates and the requirement for stratification. Additionally, seed-grown plants may take several years to reach flowering maturity. When attempting to propagate from seeds, it is advisable to sow a large quantity, as many seeds may fail to germinate.

Here are the steps for seed propagation:

1. Collect seed pods once the flowers have faded.
2. Dry the pods until they become brittle and then break them apart to extract the seeds.
3. Soak the seeds in room temperature water for 12 hours to soften their outer coating.
4. Sow the seeds about 1/4 inch deep in a sterile potting mix.
5. Place the containers in a cold location (around 40 degrees Fahrenheit) for one month. This cold stratification period is necessary to break seed dormancy and promote germination.
6. After cold treatment, move the containers to a location with temperatures around 70 degrees Fahrenheit and provide bright, indirect light until seedlings emerge. Germination can be inconsistent, ranging from seven days to three weeks, or some seeds may not germinate at all.
7. Once seedlings have developed their true leaves, gradually acclimate them to full sun.
8. Exercise caution when transplanting from pots, as Alstroemeria plants are sensitive to root disturbance, especially when young.
9. Plant seedlings in the garden with a spacing of approximately 8 inches apart to allow for their spreading growth habit.

Watering

• Watering Frequency: Alstroemerias prefer evenly moist soil, especially during their active growing season in spring and summer. Water deeply when the top inch of soil feels dry, typically about once or twice a week, depending on weather conditions.
• Avoid Waterlogging: Ensure good drainage to prevent waterlogging, as Alstroemerias are susceptible to root rot in soggy conditions. Use well-draining soil and containers with drainage holes.
• Morning Watering: Water in the morning to allow foliage to dry during the day, reducing the risk of fungal diseases.
• Reduce Water in Winter: During the dormant period in winter, reduce watering but do not let the soil dry out completely. Water sparingly to prevent the tubers from desiccating.
• Mulching: Apply a layer of mulch around the plants to retain soil moisture and suppress weeds.

Feeding

• Balanced Fertilizer: Use a balanced, slow-release fertilizer in the spring as new growth begins. You can also apply a liquid fertilizer every 2-4 weeks during the growing season.
• Organic Matter: Incorporate compost or well-rotted manure into the soil before planting to enrich the soil.
• Watering After Application: Water the plants thoroughly after applying fertilizer to help dissolve the nutrients and carry them into the root zone.
• Monitor Plant Response: Pay attention to how your Alstroemerias respond to fertilization. Yellowing leaves can indicate nitrogen deficiency, while reduced flowering may signal a need for more phosphorus or potassium.

Pruning and Deadheading

• Remove Spent Flowers: Regularly deadhead spent blooms to encourage continuous flowering and prevent the plant from diverting energy to seed production.
• Cutting Back: In late fall, after the foliage has died back, cut the stems to the ground to prepare the plant for winter dormancy.

Staking

• Support: Tall varieties may require staking to support the stems and prevent them from flopping over.
• Stake Selection: Choose sturdy stakes made of bamboo, metal, or other durable materials. The height of the stakes should be slightly taller than the expected mature height of the Alstroemeria plants.
• Placement: Position stakes around the perimeter of the plant, encircling the outer stems to provide support from all sides. Insert stakes into the ground about 6-8 inches away from the plant base to avoid damaging the roots.

In USDA zones 8 to 10 (warmer regions), Alstroemeria typically require minimal winter care beyond trimming back dying foliage. For gardeners in zone 7, which is a transitional zone, it's advisable to protect the plant roots by applying a layer of dry mulch over them during winter.

In colder zones beyond USDA zone 7, gardeners often choose to dig up and store the tubers for winter. Here’s how to do it:

1. Dig up the tubers in autumn before the ground freezes.
2. Remove excess soil by gently shaking the tubers.
3. Place the cleaned tubers in a paper bag filled with peat moss. Store them in a dry, cool location with temperatures between 35 and 41 degrees Fahrenheit for the winter.
4. In spring, once the soil has warmed to at least 60 degrees Fahrenheit, replant the tubers.
5. Spread the tubers over a mound of soil and cover them with about 2 inches of soil.
6. Keep the soil moist while waiting for new growth to emerge.

Alstroemeria plants are generally resistant to serious pests and diseases, although they can occasionally be affected by common garden pests such as aphids, slugs, mites, and whiteflies. Use appropriate treatments like insecticidal soap for aphids and slug/snail traps for mollusks.

Several significant diseases can affect Alstroemeria.

Botrytis (Gray Mold): It manifests as fuzzy, gray-brown spores on the leaves and stems of the plant. This fungal infection is challenging to treat, but you can minimize its spread by spacing plants adequately to enhance air circulation and by watering at the base of the plant instead of using overhead spraying.

Root Rot: This condition causes the leaves and stems to wilt and collapse, despite adequate watering. To prevent root rot, amend the soil to improve drainage. Allowing the soil to dry out between waterings can aid in the plant's recovery.

If severe rot sets in and the roots turn black, it's advisable to discard or destroy affected plants to prevent further spread.

Selecting Alstroemeria as a cut flower involves a few key steps to ensure they look fresh and last long in arrangements:

• Choose Mature Flowers: Select stems with fully opened flowers. Avoid buds that haven't fully developed as they may not open fully.
• Check Stem Condition: Inspect the stems for firmness and avoid those that are limp or showing signs of wilting.
• Look for Clean Foliage: Ensure the leaves are healthy and free from spots or discoloration, which can indicate disease or pest damage.
• Harvest in the Morning: Cut Alstroemeria stems early in the morning when they are hydrated and at their freshest.
• Use Sharp Pruners: Cut the stems at an angle using sharp pruners to create a clean cut, which helps the flowers absorb water more effectively.
• Remove Lower Foliage: Strip off any foliage that will be submerged in water to prevent bacterial growth and keep the water clean.
• Immediate Watering: Place the cut stems in a bucket of water immediately after cutting to prevent air bubbles from forming in the stems, which can block water uptake.
• Conditioning: Before arranging, condition the stems by placing them in lukewarm water for a few hours. This helps them rehydrate and extend their vase life.

Propagating Alstroemeria can be done through the division of the tubers or by seeds, although the latter is less common due to lower germination rates and slower growth to flowering. Here’s how to propagate Alstroemeria through division.

• Timing: Divide the tubers in early spring before new growth begins, or in fall after flowering ends.
• Digging Up Tubers: Carefully dig around the base of the plant to expose the tubers. Lift the clump of tubers out of the ground, taking care not to damage the roots.
• Separating Tubers: Gently shake off excess soil to expose the individual tubers. Using a clean, sharp knife or garden spade, divide the clump into sections, ensuring each section has several healthy tubers and some roots attached.
• Replanting: Prepare the planting site with well-draining soil enriched with compost. Plant each divided section of tubers at the same depth as they were originally growing, spacing them about 12-18 inches apart.
• Watering: Water thoroughly after planting to settle the soil around the tubers.
• Care: Keep the newly planted divisions evenly moist but not waterlogged. Once established, Alstroemeria plants are relatively low maintenance and should start producing new growth and flowers.

Alstroemeria, or Peruvian Lilies, can be paired with various companion plants that complement their growth habits and enhance garden aesthetics. Here are some great companion plants for Alstroemeria:

• Lavender (Lavandula spp.): Both Alstroemeria and lavender enjoy similar growing conditions—full sun and well-draining soil. Lavender’s aromatic foliage and purple flowers contrast beautifully with Alstroemeria’s vibrant blooms.
• Salvia (Salvia spp.): Salvia's upright spikes of flowers in shades of blue, purple, or red create a striking contrast with Alstroemeria’s trumpet-shaped blooms. They also attract pollinators, benefiting both plants.
• Agapanthus (Agapanthus spp.): These plants feature tall stems topped with clusters of bell-shaped flowers in shades of blue or white, which complement the height and structure of Alstroemeria.
• Daylilies (Hemerocallis spp.): Daylilies offer a wide range of colors and bloom shapes that can harmonize with or contrast against Alstroemeria. They thrive in similar sun and soil conditions.
• Ornamental Grasses: Grasses like Pennisetum, Miscanthus, or Carex provide textural contrast with their feathery or upright foliage. They can also add movement and interest to the garden when planted alongside Alstroemeria.
• Roses (Rosa spp.): Climbing or shrub roses with their fragrant blooms and variety of colors can create a classic and elegant combination when paired with Alstroemeria.