Best Time To Harvest Rhubarb In Minnesota

Minnesota rhubarb is best harvested in early summer, before the heat causes the stalks to become tough and stringy. Knowing the best time to harvest rhubarb in Minnesota can make the difference between a sweet, tender pie and a chewy, disappointing one. You want to catch those stalks when they are at their peak, usually from late April through early July, depending on your specific location and the weather that year.

Rhubarb is a cold-hardy perennial that thrives in Minnesota’s climate. It actually prefers the cool spring weather. Once temperatures regularly hit the 80s and 90s, the plant shifts its energy. The stalks get thicker, but they also become more fibrous and less flavorful. So timing is everything.

The sweet spot for harvesting rhubarb in Minnesota is typically from mid-May to mid-June. This is when the stalks are long, thick, and full of that perfect tartness. You want to start checking your plants as soon as the snow melts and the ground thaws.

Here is a simple rule: wait until the stalks are at least 10 to 15 inches long. Shorter stalks are often too thin and not fully developed. Longer stalks might be past their prime. You also want to look for stalks that are firm and crisp, not limp or rubbery.

Another key sign is the color. Red varieties will show a deep, rich red. Green varieties will be a bright, vibrant green. If the stalks start to look pale or washed out, they are likely getting old.

Signs Your Rhubarb Is Ready To Pick

Stalks are 10 to 15 inches long.
Stalks are firm and snap easily when bent.
Color is deep and vibrant for the variety.
Leaves are fully expanded and healthy looking.
The plant has been growing for at least two full years.

Do not harvest any stalks during the first year after planting. The plant needs that time to establish a strong root system. In the second year, you can take a few stalks, but leave most of them. By the third year, you can harvest freely for about 4 to 6 weeks.

How To Harvest Rhubarb Properly

You do not cut rhubarb stalks with a knife. That can leave a stub that rots and invites disease. Instead, use the twist-and-pull method.

Grasp the stalk near the base.
Twist it gently while pulling it sideways.
The stalk should snap off cleanly at the base.
Remove the leaves immediately, as they are toxic.

Always leave at least half of the stalks on the plant. This ensures the plant can photosynthesize and store energy for next year. If you take too many, you weaken the plant and reduce next season’s harvest.

Factors That Affect Harvest Timing In Minnesota

Minnesota is a big state with different climate zones. The best time to harvest rhubarb in Minnesota varies by region. In the southern part of the state, near the Iowa border, you might start harvesting in late April. In the northern part, near Canada, you might not start until late May or early June.

Spring weather also plays a big role. A warm, early spring means an earlier harvest. A cold, late spring means you wait longer. Pay attention to your local weather forecast and the growth of your plants.

Regional Differences Within Minnesota

Southern Minnesota: Late April to early June.
Central Minnesota: Mid-May to mid-June.
Northern Minnesota: Late May to early July.

If you live in the Twin Cities metro area, you are in central Minnesota. Your harvest window is usually from about May 10 to June 15. But again, watch your plants, not the calendar.

Weather Impact On Rhubarb Quality

Rhubarb loves cool, moist weather. If you get a lot of rain in the spring, the stalks will grow fast and stay tender. If it is dry, the stalks might be thinner and tougher. You can water your rhubarb during dry spells to help keep it tender.

Heat is the enemy. Once daytime temperatures consistently hit 80°F or higher, the quality drops fast. The stalks become stringy and the flavor turns bitter. That is why the early summer window is so critical in Minnesota.

How Long Can You Harvest Rhubarb?

You can harvest rhubarb for about 4 to 6 weeks each spring. After that, the plant needs to rest and build up energy for the next year. If you keep harvesting into July and August, you risk damaging the plant.

Some gardeners stop harvesting by the Fourth of July. Others stop when the stalks start to look thin and spindly. Either way, let the plant grow freely for the rest of the summer and fall.

Signs It Is Time To Stop Harvesting

Stalks become thin and spindly.
Stalks are tough and stringy when you try to snap them.
The plant starts to flower (bolting).
Leaves start to yellow or look tired.

If your rhubarb bolts and sends up a flower stalk, cut that stalk off at the base. This helps the plant focus on leaf and root growth instead of seed production. The flower stalk is not edible.

Can You Harvest Rhubarb In The Fall?

Technically, yes, but it is not recommended for most home gardeners. A fall harvest can weaken the plant heading into winter. In Minnesota, where winters are harsh, you want the plant to be as strong as possible.

If you absolutely need rhubarb in the fall, take only a few stalks and only from a very healthy, well-established plant. Do this early in the fall, at least 6 weeks before the first hard frost. This gives the plant time to recover.

Most experts say just stick with the spring harvest. It is safer and the quality is better anyway.

Storing And Using Fresh Rhubarb

Once you harvest your rhubarb, you need to use it or store it quickly. Fresh rhubarb will keep in the refrigerator for about 2 to 3 weeks if you store it properly.

How To Store Fresh Rhubarb

Remove all leaves and trim the ends.
Wrap the stalks loosely in a damp paper towel.
Place them in a plastic bag with some air holes.
Store in the crisper drawer of your refrigerator.

You can also freeze rhubarb for later use. Wash and chop the stalks into 1-inch pieces. Spread them on a baking sheet and freeze until solid. Then transfer to a freezer bag. Frozen rhubarb will keep for up to a year.

Do not thaw frozen rhubarb before cooking. It will turn mushy. Just add it directly to your recipes from the freezer.

Common Rhubarb Growing Mistakes In Minnesota

Even experienced gardeners make mistakes with rhubarb. Here are some common ones to avoid.

Harvesting too early: Wait until the stalks are at least 10 inches long.
Harvesting too much: Never take more than half the stalks at once.
Cutting stalks: Always twist and pull, never cut.
Leaving leaves on: Remove leaves right away to keep stalks fresh.
Ignoring weeds: Keep the area around your rhubarb weed-free.
Not dividing plants: Every 5 to 7 years, divide your rhubarb to keep it productive.

If you follow these tips, your rhubarb patch will keep producing for decades. Some Minnesota gardeners have rhubarb plants that are 20 or 30 years old.

Best Rhubarb Varieties For Minnesota

Not all rhubarb varieties are created equal. Some do better in cold climates like Minnesota. Here are a few top choices.

Victoria: A classic green variety with excellent flavor. Very hardy.
Canada Red: Deep red stalks that are sweet and tender. Great for pies.
Valentine: Bright red stalks with good flavor. Vigorous grower.
MacDonald: Canadian variety bred for cold climates. Very productive.
Riverside Giant: Large stalks with a mild flavor. Good for freezing.

All of these varieties will thrive in Minnesota’s climate. Choose based on your color preference and flavor needs.

When To Plant Rhubarb In Minnesota

If you are starting a new rhubarb patch, plant it in early spring as soon as the soil can be worked. That is usually in April in most of Minnesota. You can also plant in the fall, about 6 weeks before the first frost.

Rhubarb is usually grown from crowns, not seeds. Crowns are dormant root pieces with buds. Plant them about 2 inches deep and 3 to 4 feet apart. They need full sun and well-drained soil.

Do not expect a harvest in the first year. Let the plant grow and establish itself. You can start harvesting lightly in the second year, and fully in the third year.

Fertilizing Rhubarb For Best Growth

Rhubarb is a heavy feeder. It needs plenty of nutrients to produce those big stalks. In early spring, before growth starts, apply a balanced fertilizer like 10-10-10. Use about 1/2 cup per plant.

You can also top-dress with compost or well-rotted manure. This adds organic matter and improves soil structure. Avoid high-nitrogen fertilizers, which can cause too much leaf growth and not enough stalk development.

After the harvest season is over, give the plants another light feeding. This helps them store energy for winter.

Winter Care For Rhubarb In Minnesota

Minnesota winters are brutal, but rhubarb is very cold-hardy. It can survive temperatures down to -40°F. Still, a little winter care helps.

In late fall, after the leaves have died back, cut off the dead foliage. This removes hiding places for pests and diseases. Then apply a 2 to 4 inch layer of mulch, like straw or shredded leaves, over the crown. This insulates the soil and prevents heaving from freeze-thaw cycles.

Remove the mulch in early spring as soon as the ground starts to thaw. This allows the new shoots to emerge easily.

Pests And Diseases Of Rhubarb In Minnesota

Rhubarb is relatively pest-free, but a few issues can arise. The most common is rhubarb curculio, a small beetle that feeds on the stalks. You can control it by hand-picking and removing weeds around the patch.

Another issue is crown rot, which is caused by wet, poorly drained soil. Make sure your rhubarb is planted in well-drained soil. If you see mushy, rotting crowns, dig up the plant and discard it.

Leaf spot is a fungal disease that causes brown spots on the leaves. It is usually not serious. Just remove and discard the affected leaves.

Frequently Asked Questions

Can I harvest rhubarb after it flowers?

Yes, but the quality may decline. The stalks become tougher and more fibrous. It is better to remove the flower stalk as soon as you see it.

Is it safe to eat rhubarb leaves?

No. Rhubarb leaves contain oxalic acid, which is toxic. Always remove and discard the leaves immediately after harvesting.

How do I know if my rhubarb is too old to harvest?

If the stalks are thick but feel spongy or stringy, they are past their prime. Also, if the stalks have a pale, washed-out color, they are old.

Can I harvest rhubarb in the first year after planting?

No. Wait until the second year for a light harvest, and the third year for a full harvest. The plant needs time to establish its root system.

What is the best way to use rhubarb?

Rhubarb is most commonly used in pies, crisps, and sauces. It pairs well with strawberries. You can also make rhubarb jam, chutney, or even wine.

Final Tips For A Great Rhubarb Harvest

To get the most out of your rhubarb patch, keep these final tips in mind. First, always harvest in the morning when the stalks are crisp and full of moisture. Second, never harvest when the stalks are wet from rain, as this can spread disease. Third, rotate your harvest spots each year to avoid stressing any one part of the plant.

Rhubarb is one of the easiest and most rewarding plants to grow in Minnesota. With a little care and the right timing, you can enjoy fresh, tender stalks every spring for years to come. Just remember the golden rule: harvest early, harvest often, but never take too much.

Now you know the best time to harvest rhubarb in Minnesota. Get out there and enjoy that tart, tangy goodness while it lasts. Your taste buds will thank you.