If you’re a Michigan gardener, knowing when to plant rhubarb is the first step to a great harvest. Getting the timing right gives your plants the best start for years of reliable growth. This guide will walk you through the best planting times for rhubarb in Michigan’s unique climate.
Rhubarb is a hardy perennial that can thrive here for a decade or more. Planting it at the correct time is crucial for establishing strong roots. Let’s look at the ideal seasons and methods to ensure your success.
When To Plant Rhubarb In Michigan
The absolute best time to plant rhubarb in Michigan is in early spring. This means as soon as the ground is workable, usually from late March to mid-April. The cool, moist conditions of spring are perfect for helping new roots establish before summer’s heat.
Fall is also a suitable secondary planting window. Aim for late August to mid-September. This gives the plant enough time to settle in before the ground freezes solid. Avoid planting too late in fall, as the crowns may heave out of the soil during winter freeze-thaw cycles.
Why Spring Planting is Ideal
Spring planting aligns with the plant’s natural growth cycle. As the soil warms, the rhubarb crown wakes from dormancy and directs its energy into root development. This strong root system supports vigorous leaf and stalk growth by early summer.
Planting in spring also allows the rhubarb to benefit from Michigan’s typically reliable spring rainfall. Consistent moisture is key for new transplants. You avoid the stress of summer drought during those critical first weeks.
Understanding Your Michigan Growing Zone
Michigan spans USDA Hardiness Zones 4 through 6. This affects your precise planting date. Check your specific zone to fine-tune your schedule.
- Zones 4 & 5 (Upper & Northern Lower Peninsula): Plant from late April to mid-May in spring. For fall, aim for early September.
- Zone 6 (Southern Lower Peninsula): You can often plant a bit earlier, from late March to early April in spring. Fall planting can extend into late September.
A good rule is to watch the soil, not just the calendar. If the soil is no longer soggy from snowmelt and crumbles easily in your hand, it’s time to plant.
How to Plant Rhubarb: A Step-by-Step Guide
Rhubarb is typically planted from dormant crown divisions or potted starts. Seeds are not recommended, as they take much longer and produce variable results.
Step 1: Choose the Right Spot
Select a site with full sun (at least 6 hours daily). Rhubarb can tolerate partial shade, especially in hotter parts of southern Michigan, but full sun yields the best stalks. The location should have well-draining soil to prevent crown rot. Avoid low spots where water pools.
Step 2: Prepare the Soil
Michigan soils often benefit from ammendment. Rhubarb prefers fertile, slightly acidic to neutral soil.
- Dig a hole about 18 inches wide and deep.
- Mix the native soil with several inches of compost or well-rotted manure.
- Add a balanced, slow-release fertilizer according to package directions.
Step 3: Plant the Crown Correctly
- Place the rhubarb crown in the hole so the the buds (or “eyes”) are 1-2 inches below the soil surface.
- Spread the roots out gently.
- Backfill the hole with your soil mixture, firming it gently around the crown.
- Water thoroughly to settle the soil and eliminate air pockets.
Step 4: Spacing and Ongoing Care
Space rhubarb plants 3 to 4 feet apart. They get very large! Apply a 2-3 inch layer of mulch around the plant to conserve moisture and suppress weeds. Water regularly during the first growing season, especially during dry spells.
What to Avoid in the First Year
Patience is essential with rhubarb. Do not harvest any stalks in the first year. This allows the plant to put all its energy into building a robust root system. In the second year, you can harvest lightly for a few weeks. By the third year, your plant will be fully established and you can harvest for 8-10 weeks in spring.
Avoid overwatering, which can lead to rot. Let the soil dry slightly between waterings. Also, remove any flower stalks that appear, as flowering reduces leaf and stalk vigor.
Fall Planting Considerations
If you miss the spring window, fall planting can work. The key is to give the plant about 6 weeks of growing time before a hard freeze. Mulch heavily around the new crown after planting with straw or shredded leaves. This insulates the soil and protects the young roots from sudden temperature swings.
Fall-planted rhubarb may be slightly slower to establish than spring-planted ones. But with good mulch, it will be ready to take off the following spring.
Common Michigan Rhubarb Planting Mistakes
Even experienced gardeners can make a few errors. Here’s what to watch for:
- Planting too deep: This can cause the crown to rot. Keep the buds just below the surface.
- Crowding plants: Giving them ample space ensures good air circulation and reduces disease risk.
- Harvesting too soon: Resist the temptation! Let the plant get strong first.
- Poor site selection: Planting in heavy, wet clay without improving drainage is a common cause of failure.
FAQ: Planting Rhubarb in Michigan
Can I plant rhubarb from seed in Michigan?
You can, but it’s not practical. Rhubarb grown from seed can take 3-4 years to produce a harvestable crop, and the plant characteristics are unpredictable. Using crown divisions is faster and reliable.
What are the best rhubarb varieties for Michigan?
‘Canada Red’ and ‘Crimson Red’ have excellent color and sweetness. ‘Victoria’ is a reliable green-stalked variety that is very hardy. All are well-suited for Michigan’s winters.
Is it too late to plant rhubarb in May?
Early May is usually fine, especially in cooler zones. Late May planting is possible, but you’ll need to be diligent about watering to help the plant cope with the approaching summer heat.
Can I divide and replant existing rhubarb in spring?
Yes, early spring is the perfect time to divide mature rhubarb plants. Dig up the whole crown and use a sharp spade to cut it into sections, each with at least one bud. Replant immediately.
How do I protect newly planted rhubarb from a late frost?
Rhubarb is very cold-tolerant. A late light frost usually won’t harm new shoots. If a hard freeze is expected after planting, you can cover the crown with a bucket or a thick layer of straw temporarily.
By following these guidelines on timing and technique, you’ll give your rhubarb the foundation it needs. With proper care, a single planting can provide you with tangy, homegrown stalks for many Michigan springs to come.