oxalis bulbs when to plant

When is the Best Time to Plant Oxalis Bulbs for Maximum Blooms?

Oxalis bulbs also known as wood sorrels or shamrocks, are a popular choice for gardens and containers. Known for their bright clover-shaped leaves and delicate flowers, they add a festive touch of good luck wherever planted. But timing is everything when it comes to oxalis bulbs. Plant them at the right time and you’ll be rewarded with a gorgeous floral display. Get the timing wrong, however, and your oxalis may struggle or fail to thrive.

So when should you plant these charmed bulbs for the best blooms? Read on to learn all about oxalis bulb planting times and tips for success.

An Overview of Oxalis Varieties

There are over 800 oxalis species, but some of the most common bulbs include:

• Oxalis triangularis (purple shamrock): Deep purple, triangular foliage with pale pink blooms.

• Oxalis tetraphylla (lucky shamrock): Traditional four-leaf clovers with white or pink flowers.

• Oxalis deppei (golden shamrock): Bright lime green leaves and yellow blooms.

• Oxalis versicolor (candy cane shamrock): Deep red-veined leaves resembling candy canes. Pinkish-white flowers.

While foliage colors and shapes vary, all oxalis bulbs grow from underground bulb-like rhizomes and prefer either spring or fall planting.

Ideal Spring Planting Time

Some oxalis varieties like purple, candy cane, and golden shamrocks thrive when spring planted. Spring planting coincides with their natural bloom period and gives bulbs time to establish before summer dormancy.

The optimal spring planting window is after your region’s last expected frost date when soil temperatures reach 60°F. This is usually in March or April. Oxalis can tolerate light frosts but avoid planting too early when freezing nights are still common. If planting containerized bulbs, bring them indoors until it’s safe to transplant outside.

Aim for early to mid spring planting for best results. This allows at least 8-10 weeks of growth before hot summer temperatures trigger dormancy.

Tips for Spring Oxalis Planting:

• Prepare beds by mixing in compost to improve drainage. Oxalis hate wet soil!

• Plant bulbs 4-6 inches apart and 1-2 inches deep in well-draining soil. Overly deep holes can rot bulbs.

• Water moderately after planting and provide 1 inch of water weekly as they establish.

• Fertilize monthly with balanced liquid fertilizer once foliage emerges.

Follow these guidelines for spring blooms starting 8-10 weeks after planting.

Ideal Fall Planting Time

Fall-blooming oxalis varieties like lucky shamrocks do best when planted in autumn. Fall planting gives bulbs time to develop roots before going dormant for winter.

For fall planting, aim to put bulbs in the ground 6-8 weeks before your first expected autumn frost. This is typically September to October depending on your climate. Avoid late fall planting when freezing temps are around the corner. If needed, potted bulbs can be held indoors until conditions improve.

Fall Oxalis Planting Tips:

• Loosen soil and mix in compost or organic matter to improve drainage before planting.

• Space bulbs 4 inches apart and plant 1-2 inches deep. Don’t plant too deeply or bulbs may rot.

• Water lightly after fall planting and provide 1 inch of water weekly until the ground freezes.

• Fertilize monthly with diluted liquid fertilizer to encourage root growth before dormancy.

• Apply 2-3 inches of mulch in late fall to protect bulbs from cold.

With proper fall planting, expect foliage to emerge the following spring, followed by blooms 4-6 weeks later.

Growing Oxalis as Perennials vs. Annuals

Most oxalis varieties are hardy in Zones 7-10 and can be grown as perennials, returning each year. In colder areas they work best as annuals, replaced each season. Consider these tips:

• In Zones 7-10, plant in permanent beds, fertilize regularly, and leave bulbs in the ground year-round.

• In Zones 3-6, grow in containers that can be brought indoors for winter. Discard spent bulbs rather than forcing dormancy.

• In cold winter zones, plant in fall and mulch heavily. Dig up bulbs after foliage dies back and store dormant until spring replanting.

Annual planting works, but perennial oxalis deliver the most impressive long-lasting display.

Maximizing Bloom Time Through Successive Planting

Successive planting, or planting bulbs in waves, can extend oxalis bloom time. Follow this sample schedule:

• First wave – plant in early spring

• Second wave – plant 2-3 weeks after first batch

• Third wave – plant 2-3 weeks after second batch

This approach works for both spring and fall planted oxalis. Adjust timing for your climate and variety. Properly timed successive planting can stretch oxalis blooms from early spring into summer!

Ideal Container Planting Times

Containers offer more flexibility than in-ground planting. Here are suggested container planting times:

• Spring – Start indoors 4-6 weeks before your last frost. Harden off and transplant after all danger of frost passes.

• Summer – Plant in containers in early summer for fall blooms. Provide afternoon shade and regular watering. Before first frost, bring containers indoors.

• Fall – Start bulbs in containers 6-8 weeks before your first fall frost. Grow indoors in a sunny window over winter.

• Winter – Purchase dormant bulbs and start indoors 6-8 weeks before desired bloom time.

Monitor your climate and time indoor planting accordingly for beautiful oxalis in containers.

Adjusting Oxalis Planting Times by Growing Zone

These general guidelines should be tailored to your specific USDA Hardiness Zone and local spring/fall conditions:

• Zones 3-4: Target fall planting in September before frost. Mulch heavily for winter protection. Store bulbs dormant indoors over winter.

• Zones 5-6: Plant in early fall (late September) or early spring (late March). Protect with thick mulch over winter.

• Zones 7-8: Spring or fall planting works well. No need to dig bulbs up over winter.

• Zones 9-10: Focus on spring planting after danger of frost has passed (Feb/March). Provide shade in summer.

• Northern Climates: Delay planting until late fall (Nov) or mid/late spring to avoid frost damage.

• Southern Climates: Plant earlier in fall (Oct) and spring (Feb). Offer bright light and prevent excess summer heat.

Also consider your specific climate patterns and seasonal variations. Adjust oxalis planting dates accordingly.

Signs Bulbs Were Planted Too Early

Planting oxalis at the wrong time, especially too early, can cause issues. Here are signs your bulbs went in too soon:

• Slow emergence and growth – Bulbs planted in cold soil are slow to wake up and sprout. It may take 6+ weeks before any growth appears.

• Pale, stunted foliage – Chilly soils prevent proper greening and foliage growth is stunted.

• No blooms – Flowers require adequately warm soil and air temperatures. Too-early planting means few or no blooms.

• Rotting bulbs – Bulbs planted in cold, wet conditions often rot away to mush.

• Failure to resprout – Bulbs that don’t establish well enough before winter may not resprout the following season.

Don’t worry if your bulbs show these signs! Simply replant at the proper time and they should recover well. Adjust your planting date based on issues experienced.

Consequences of Planting Too Late

While early planting brings clear risks, late planting also causes problems:

• Small or no flowers – Blooming requires sufficient time to mature. Late planting results in weak or no blooms before frost.

• Poor winter survival – Fall bulbs need time to develop roots before going dormant. Late planting provides no prep time for winter.

• Delayed spring emergence – With less fall growth, late planted bulbs are slower to wake up in spring.

• Smaller foliage – Less mature bulbs produce smaller, weaker foliage when growth resumes.

• Pushed back blooms – Expect significantly delayed blooming, sometimes not occurring until the following season.

As with early planting, don’t worry if your bulbs go in late. Make notes to plant earlier next year, provide optimal care, and the bulbs should recover well.

Key Oxalis Planting Mistakes to Avoid

While generally easy to grow, avoid these common oxalis planting errors:

• Planting too early – Wait until soil is minimum 60°F to avoid frost damage.

• Planting too late – Fall bulbs need 6-8 weeks before frost. Spring bulbs that miss bloom window will underperform.

• Planting too deep – Oxalis bulbs should be planted just 1-2” deep. Overly deep holes cause rotting.

• Forgetting to pre-chill – If planting dormant spring bulbs, they need 6-8 weeks of refrigeration first.

• Letting soil dry out – Oxalis require moderately moist soil when sprouting. Don’t let planting beds or containers dry out completely.

• Insufficient sunlight – Provide at least 4-6 hours of direct sun for robust growth and abundant blooms.

Learn from these mistakes to become an oxalis bulb planting expert!

Frequently Asked Questions About Oxalis Bulb Planting

Here are quick answers to some common questions about when and how to plant oxalis bulbs:

What is the best month to plant oxalis bulbs?

• Spring bloomers – March to April

• Fall bloomers – September to October

How soon after planting oxalis will they bloom?

Expect flowers 6 to 12 weeks after planting depending on variety. Foliage typically emerges within 3 to 6 weeks.

Should oxalis bulbs be planted in spring or fall?

Spring planting suits spring bloomers. Fall planting is best for fall bloomers. Choose timing based on variety.

Can oxalis bulbs be planted in summer?

Most oxalis go dormant in summer heat, so it’s a poor planting time. Focus on spring or fall for best results.

How cold tolerant are oxalis bulbs?

Oxalis can tolerate light frosts but avoid planting until overnight temps consistently stay above 35°F.

How deep should oxalis bulbs be planted?

Plant oxalis bulbs 1-2” deep. Any deeper risks rotting. Shallower is fine as long as bulbs are covered.

Get Lucky With Perfectly Timed Oxalis Planting

While easy-going bulbs, oxalis still thrive when properly planted at the ideal time. Matching their spring or fall growth habits with suitable soil temperatures and care leads to the healthiest start. Avoid disappointments from frost, rotting, or weak blooms by following these guidelines for your region. With the perfect oxalis bulb planting schedule, these cheerful charms will fill your garden or containers with bountiful blooms and beautiful foliage.

To grow oxalis from bulbs (or corms), plant them 1-2 inches deep with the pointed end facing up in well-draining potting mix. Space the bulbs 3-4 inches apart. Water lightly after planting and keep the soil consistently moist, but not waterlogged.