When to Plant Oxalis Bulbs for a Bright and Cheery Garden

Oxalis, also known as wood sorrel or shamrocks, are a classic and easy-to-grow bulb that brings pops of color and lively foliage to gardens and containers Known for their clover-shaped leaves and delicate flowers in shades of white, pink, yellow, and purple, oxalis add a touch of good luck and charm wherever they are planted But when is the right time to put those oxalis bulbs in the ground for the best results? Understanding oxalis’ growth habits and timing your planting correctly can make all the difference between these bulbs thriving or failing.

In this comprehensive guide, we’ll go over everything you need to know about when to plant oxalis bulbs, from preferred planting seasons and ideal timing to tips for success. After reading, you’ll be ready to perfectly time your oxalis bulb planting for a gorgeous and carefree display.

Overview of Oxalis Bulb Types

There are over 800 varieties of oxalis, but some of the most popular bulbs for gardens include:

• Oxalis triangularis (purple shamrock): Striking deep purple triangular foliage with pale pink blooms.

• Oxalis tetraphylla (lucky shamrock): A traditional lucky shamrock with clover-like leaves and white or pink flowers.

• Oxalis deppei (golden shamrock) Lime-green foliage with delicate yellow blooms

• Oxalis versicolor (candy cane sorrel): Deep red-veined foliage that resembles candy cane stripes. White or pink flowers.

While the foliage colors and shapes vary, all oxalis bulbs grow from underground rhizomes or small bulb-like structures. They go dormant in summer and prefer to be planted in spring or fall, depending on the variety.

Spring Oxalis Bulb Planting

Some oxalis varieties, like the purple shamrock (O. triangularis), candy cane oxalis (O. versicolor), and golden shamrock (O. deppei) are spring-blooming and do best when planted in early spring. This lines up with their natural bloom time and gives the bulbs time to establish roots before putting on a floral display.

Ideal spring planting time is after the last frost date when soil temperatures reach 60°F, usually around March/April. Oxalis can tolerate some frost but avoid planting too early when freezing temperatures are still common.

For potted oxalis bulbs, you can bring them indoors until outdoor conditions improve. Just make sure they receive plenty of sunlight from a south-facing window.

Spring planting tips:

• Prepare the planting area in advance by mixing in compost or organic material to improve drainage. Oxalis hate wet feet!

• Space bulbs 4-6 inches apart and plant 1-2 inches deep in well-drained soil. Deeper holes can rot the bulbs.

• Water moderately after planting and provide 1 inch of water per week during growth.

• Fertilize monthly with a balanced liquid fertilizer once foliage emerges.

Follow these spring guidelines, and your oxalis will send up foliage within 4 weeks and blooms by 8-10 weeks after planting.

Fall Oxalis Bulb Planting

Other popular oxalis varieties like O. tetraphylla and O. regnellii are fall-blooming and do best when planted in autumn. While they will tolerate spring planting, fall allows the bulbs to become established before winter dormancy.

The ideal fall planting window is 6-8 weeks before your average first frost date, usually September/October. Avoid late fall planting when freezing temperatures are imminent. Potted bulbs can be brought inside until it’s safe for planting outdoors.

Fall oxalis planting tips:

• Prepare beds by loosening soil and mixing in compost. Good drainage is key!

• Plant bulbs 4 inches apart and 1-2 inches deep. Planting too deeply can lead to rot.

• Water lightly after planting and provide an inch of water per week until the ground freezes.

• Fertilize monthly with diluted liquid fertilizer for faster root growth before dormancy.

• Add a 2-3 inch mulch layer in late fall for cold protection.

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

Planting Oxalis as Perennials vs. Annuals

Most oxalis varieties are hardy in USDA Zones 7-10 and can be planted as perennials, returning year after year. In colder climates, they can be planted as annuals and replaced yearly. Here are a few tips:

• In Zones 7-10, plant oxalis in a permanent spot in your garden, fertilize regularly, and allow the bulbs to remain in the ground year-round.

• In Zones 3-6, plant oxalis in containers that can be brought indoors over winter. Discard the bulbs after they bloom rather than forcing dormancy.

• In areas with freezing winters, plant in fall and mulch heavily. Dig up bulbs after foliage dies back and store dormant in a cool place until spring replanting.

Choose the best planting strategy for your zone to maximize oxalis’ performance. Annual planting works great, but perennials deliver the most dramatic and lasting display.

Extending the Bloom Season Through Successive Planting

One of the best tricks for enjoying oxalis flowers over a longer window is successive planting. This simply means planting bulbs in waves, spaced 2-4 weeks apart. The first batch blooms earliest, followed by the second and third plantings for continuous color.

Here’s a sample successive planting schedule:

• First wave: plant in early spring (March/April)

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

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

This planting strategy works for both spring and fall oxalis. Just make sure to adjust timing based on your local climate and the variety you are growing. With proper timing, you can stretch oxalis bloom time from early spring through summer!

Container Planting for Flexible Timing

Containers offer more flexibility for when to plant oxalis bulbs compared to planting directly in garden beds. Here are some tips if you want to get a jump start with container oxalis:

• Start bulbs indoors 6-8 weeks before your last frost date. Use a potting mix in containers with drainage holes.

• Provide bright light from a south window and grow at 65°F minimum.

• Hardened off bulbs by setting containers outdoors 1-2 weeks before transplanting to the garden.

• In fall, start bulbs in containers 6-8 weeks before you want blooms. Grow indoors over winter.

• Transplant established container oxalis to the garden in spring or fall.

Container planting allows you to push both spring and fall oxalis planting earlier for faster flowers!

Adjusting Planting Times for Your Region

These general oxalis bulb planting guidelines should be adjusted based on your specific USDA Hardiness Zone and local spring/fall conditions:

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

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

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

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

• South: Plant earlier in fall (October) and spring (February). Provide bright light and avoid excess summer heat.

• North: Delay planting until late fall (November) and mid/late spring (April/May) to avoid frost damage.

Within your zone, also consider your specific climate patterns and seasonal variations from year to year. Adjust oxalis bulb planting dates accordingly for best results!

signs that oxalis bulbs have been planted too early

Planting oxalis bulbs at the wrong time can set them up for failure. Here are a few signs that your bulbs were put in too early and are struggling:

• Slow growth and emergence: Bulbs planted in cold soil will be slow to wake up and start growing. It can take 6 weeks+ before you see any sprouting.

• Pale, stunted foliage: Chilly spring soils prevent proper greening of the leaves. Growth will be weak and spindly.

• No flowers: Blooming requires warm soil and air temps. Too-early planting means flowers are sparse or non-existent.

• Rotting bulbs: Bulbs planted in cold, wet soil often develop fungal rot and turn to mush.

• Failure to resprout: When bulbs haven’t established enough before winter, they might not have the energy to resprout the following season.

If you notice these signs, don’t worry! Simply replant bulbs at the proper time and they should recover well. Adjust your planting date earlier or later based on the issues you experienced.

What if bulbs are planted too late?

While early planting has clear risks, planting oxalis bulbs too late in the season can also cause problems:

• Small or no flowers: Blooming requires adequate time to grow and mature. Late planting means weak or no flowers before frost.

• Poor winter survival: Fall bulbs need time to establish roots before going dormant. Late planting gives no time to prep for winter.

• Slow spring emergence: With less time to grow in fall, late-planted bulbs are slower to wake up when spring arrives.

• Smaller foliage: Less mature bulbs produce smaller and more spindly foliage when growth resumes.

• Delayed blooming: Expect blooming to be pushed back significantly, sometimes not occurring until the following season.

Again, don’t despair if your bulbs go in late. Just make note to plant earlier next year. Give the bulbs optimal care and they will recover!

Timing Oxalis Container Planting

Container planting allows more leeway in terms of planting schedule since you can control factors like temperature and moisture. Here are some container planting tips:

Spring – Start containers indoors 4-6 weeks before your last expected frost. Acclimate bulbs to outdoor conditions before transplanting into the garden after all danger of frost.

Summer – Plant in containers in early summer for flowers in fall. Provide afternoon shade and water regularly. Bring containers indoors before first frost.

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

Winter – The perfect time to find oxalis bulb deals online! Plant dormant bulbs in containers indoors 6-8 weeks before wanted bloom time.

Monitor outdoor conditions and time indoor container planting accordingly for a perfect oxalis display!

Common Oxalis Planting Mistakes to Avoid

While oxalis are generally very forgiving bulbs, there are a few common planting pitfalls to avoid:

• Planting too early – Be patient and wait for soil temperatures to reach 60°F before planting oxalis. Early sprouting makes them vulnerable to frost damage.

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

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

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

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

• Insufficient sunlight – Give oxalis a minimum of 4-6 hours of direct sun for robust growth and plentiful blooms.

Learn from these common mistakes to become an oxalis planting pro!

Oxalis Planting FAQs

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

What is the best month to plant oxalis bulbs?

• Spring bloomers: March-April
• Fall bloomers: September-October

How soon after planting oxalis will they bloom?

Expect flowers 6 to 12 weeks after planting, depending on the variety. Foliage emerges after 3 to 6 weeks.

Should oxalis bulbs be planted in spring or fall?

Spring planting is best for spring bloomers, while fall planters are ideal for fall bloomers. Choose based on variety!

Can oxalis bulbs be planted in summer?

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

How cold tolerant are oxalis bulbs?

Oxalis tolerate light frosts but avoid planting until outdoor overnight temps stay above 35°F to be safe.

How deep should oxalis bulbs be planted?

Plant oxalis bulbs just 1-2” deep. Any deeper risks rotting. Shallower is fine, provided bulbs are covered.

Achieve Oxalis Success Through Proper Planting Timing

While easy-going and willing bloomers, oxalis bulbs still benefit from proper planting care and timing. Matching their spring or fall growth habits with ideal soil temperatures and care is key to getting these charming bulbs off to their healthiest start. Avoid disappointments from frost damage, rotting, or weak blooms by following the guidelines above for your climate. With the right oxalis bulb planting schedule, these lucky shamrocks will deliver a bounty of cheery color to brighten your garden or containers all season long!