Growing Rhubarb: A Comprehensive Guide to Planting, Care, and Harvesting

Rhubarb, with its tart stalks and vibrant color, is a delightful addition to any garden. While often treated as a fruit in culinary applications, rhubarb is botanically a vegetable. It’s a perennial plant, meaning it returns year after year, offering a consistent harvest for many years if properly cared for. This comprehensive guide will walk you through every step of growing rhubarb, from selecting the right variety to harvesting the stalks and ensuring a bountiful crop for years to come.

## Understanding Rhubarb

Before diving into the specifics of growing rhubarb, it’s helpful to understand the plant’s basic characteristics and needs.

* **Hardiness:** Rhubarb is a hardy perennial, thriving in USDA plant hardiness zones 3-8. It needs a period of cold dormancy (temperatures below 40°F or 4.4°C) to produce well. Warmer climates may struggle to provide this necessary chill.
* **Plant Structure:** Rhubarb consists of large, broad leaves and thick, fleshy stalks (petioles) that grow from an underground rhizome. It’s crucial to **only consume the stalks**, as the leaves contain high levels of oxalic acid and are poisonous.
* **Sunlight:** Rhubarb prefers full sun, ideally at least six hours of direct sunlight per day. However, it can tolerate partial shade, especially in hotter climates.
* **Soil:** Well-drained, fertile soil is essential for rhubarb growth. The soil should be rich in organic matter and have a slightly acidic to neutral pH (6.0-6.8).
* **Water:** Rhubarb needs consistent moisture, especially during dry periods. Aim to keep the soil evenly moist, but avoid overwatering, which can lead to root rot.

## Choosing the Right Rhubarb Variety

Several rhubarb varieties are available, each with slightly different characteristics in terms of stalk color, flavor, and growth habit. Here are a few popular options:

* **’Victoria’:** A classic variety with green stalks tinged with red. It’s known for its reliability and good flavor.
* **’Crimson Red’:** As the name suggests, this variety produces bright red stalks with a sweet-tart flavor. It is more decorative in the garden than ‘Victoria’.
* **’Valentine’:** Another red-stalked variety, ‘Valentine’ is prized for its early harvest and excellent flavor.
* **’Canada Red’:** Renowned for its consistent deep-red color, sweetness, and tenderness. A great choice for those who love rhubarb desserts.
* **’German Wine’:** This heirloom variety has thicker green stalks with a red blush at the base. It is known for its tangy flavour.
* **’Strawberry Red’:** Produces long, vibrant red stalks with an intense strawberry-like sweetness. Best for pies and jams.

Consider your local climate and desired flavor profile when selecting a rhubarb variety.

## Planting Rhubarb: Step-by-Step Instructions

There are two primary ways to start rhubarb: from crowns or from seeds. Growing from crowns is generally recommended, as it’s faster and more reliable.

### Starting from Rhubarb Crowns

Rhubarb crowns are sections of the rhizome with buds (eyes) that will develop into new plants. Here’s how to plant rhubarb crowns:

1. **Timing:** The best time to plant rhubarb crowns is in early spring (as soon as the ground can be worked) or in late fall (after the plant has gone dormant). Fall planting allows the crown to establish roots before winter.
2. **Preparing the Soil:** Choose a sunny location with well-drained soil. Amend the soil with plenty of compost or well-rotted manure to improve fertility and drainage. Dig a hole that is about 18 inches (45 cm) wide and 12 inches (30 cm) deep.
3. **Planting the Crown:** Place the rhubarb crown in the hole, ensuring that the buds (eyes) are facing upwards and are about 1-2 inches (2.5-5 cm) below the soil surface. Space crowns 3-4 feet (90-120 cm) apart to allow for ample growth.
4. **Backfilling and Watering:** Gently backfill the hole with soil, firming it around the crown. Water thoroughly after planting to settle the soil and provide moisture to the roots.
5. **Mulching:** Apply a layer of mulch, such as straw or wood chips, around the base of the plant to help retain moisture, suppress weeds, and regulate soil temperature. Keep the mulch a few inches away from the crown to prevent rot.

### Starting from Rhubarb Seeds

Growing rhubarb from seed is a more lengthy process than planting crowns, and the resulting plants may not be true to type (i.e., they may not have the exact characteristics of the parent plant). However, it can be a rewarding experience.

1. **Starting Seeds Indoors:** Start rhubarb seeds indoors 8-10 weeks before the last expected frost. Sow the seeds in small pots or trays filled with seed-starting mix. Keep the soil moist and provide warmth (around 70-75°F or 21-24°C) for germination.
2. **Germination:** Rhubarb seeds typically germinate within 1-2 weeks. Once the seedlings emerge, provide them with plenty of light, either from a sunny window or a grow light.
3. **Transplanting Seedlings:** Once the seedlings have developed several sets of true leaves and the danger of frost has passed, harden them off by gradually exposing them to outdoor conditions over a period of 1-2 weeks. Transplant the seedlings into the garden, following the same soil preparation and spacing guidelines as for crowns.
4. **First Year Care:** Rhubarb plants grown from seed usually are not harvested until their second year. Allow the plants to establish strong root systems during their first year by removing any flower stalks that appear and providing consistent watering and fertilization.

## Caring for Rhubarb Plants

Rhubarb plants require consistent care to thrive and produce a bountiful harvest. Here are some essential care tips:

* **Watering:** Rhubarb needs consistent moisture, especially during dry periods. Water deeply when the top inch of soil feels dry to the touch. Avoid overhead watering, as this can promote fungal diseases. Soaker hoses or drip irrigation are ideal for delivering water directly to the roots.
* **Fertilizing:** Rhubarb is a heavy feeder and benefits from regular fertilization. In early spring, before the new growth emerges, apply a balanced fertilizer (e.g., 10-10-10) or a nitrogen-rich fertilizer (e.g., ammonium sulfate) to promote strong stalk growth. Side-dress the plants with compost or well-rotted manure in the summer to provide additional nutrients.
* **Weeding:** Keep the area around the rhubarb plants free of weeds, as they can compete for nutrients and moisture. Mulching can help suppress weed growth.
* **Flower Stalk Removal:** Rhubarb plants will occasionally produce flower stalks. Remove these stalks as soon as they appear, as they divert energy away from stalk production. Simply snap or cut the stalks off at the base.
* **Pest and Disease Control:** Rhubarb is generally resistant to pests and diseases. However, it can occasionally be affected by crown rot, which is caused by fungal pathogens in poorly drained soil. To prevent crown rot, ensure that the soil is well-drained and avoid overwatering. Slugs and snails may also occasionally feed on rhubarb leaves. Use slug bait or handpick them off the plants.
* **Division:** After several years, rhubarb plants may become overcrowded and less productive. To rejuvenate them, divide the crowns in early spring or late fall. Dig up the entire plant and carefully divide the rhizome into sections, each with at least one bud (eye). Replant the divisions in prepared soil, following the same planting guidelines as for crowns.

## Harvesting Rhubarb

Knowing when and how to harvest rhubarb is crucial for ensuring a continuous supply of stalks and maintaining the health of the plant.

* **Timing:** Do not harvest rhubarb stalks during the first year after planting, whether from crowns or seeds. This allows the plant to establish a strong root system. In the second year, you can harvest a few stalks, but limit the harvest to a few weeks. In subsequent years, you can harvest rhubarb for 8-10 weeks, typically from late spring to early summer.
* **Harvesting Technique:** To harvest rhubarb stalks, grasp the stalk near the base and gently pull and twist. The stalk should detach easily from the crown. Avoid cutting the stalks, as this can leave a stub that can rot. It is recommended to harvest no more than one-third of the stalks at a time to ensure the plant’s continued health and vigor.
* **Discarding Leaves:** Immediately after harvesting, remove the leaves from the stalks and discard them. **Remember that rhubarb leaves are poisonous and should not be consumed.** Compost the leaves or dispose of them properly.
* **Post-Harvest Handling:** Wash the rhubarb stalks and store them in the refrigerator for up to a week. For longer storage, rhubarb can be frozen. Chop the stalks into smaller pieces and blanch them in boiling water for 1-2 minutes. Cool them in ice water, drain well, and freeze them in freezer bags or containers.

## Troubleshooting Common Rhubarb Problems

Even with careful planning and maintenance, you may encounter some problems while growing rhubarb. Here are some common issues and how to address them:

* **Small, Thin Stalks:** Small, thin stalks can be caused by several factors, including insufficient sunlight, poor soil fertility, overcrowding, or lack of water. Ensure that the rhubarb plants are receiving at least six hours of direct sunlight per day. Amend the soil with compost or fertilizer to improve fertility. Divide overcrowded plants to give them more space to grow. Water regularly, especially during dry periods.
* **Yellowing Leaves:** Yellowing leaves can indicate overwatering, nutrient deficiencies, or disease. Check the soil drainage and avoid overwatering. Fertilize the plants with a balanced fertilizer to address nutrient deficiencies. Inspect the plants for signs of disease, such as crown rot, and take appropriate measures.
* **Flower Stalks:** As mentioned earlier, flower stalks should be removed as soon as they appear to prevent the plant from diverting energy away from stalk production.
* **Crown Rot:** Crown rot is a fungal disease that can cause the crown of the rhubarb plant to rot and die. It is often caused by poorly drained soil and overwatering. To prevent crown rot, ensure that the soil is well-drained and avoid overwatering. If crown rot occurs, remove the affected plant material and improve drainage around the remaining plants.
* **Pests:** While Rhubarb isn’t particularly susceptible to pests, occasionally aphids can be found on the underside of the leaves. A strong blast of water from a garden hose can often dislodge these pests. Snails and slugs can also be an issue, eating holes in the leaves. Use slug bait or handpick them off the plants, especially after a rain.

## Using Your Rhubarb Harvest

Rhubarb’s tart flavor makes it a versatile ingredient in a variety of dishes. Here are some popular ways to use your rhubarb harvest:

* **Pies and Crumbles:** Rhubarb pie and rhubarb crumble are classic desserts that showcase the plant’s unique flavor. Combine rhubarb with other fruits, such as strawberries or apples, for a sweeter and more complex flavor.
* **Jams and Preserves:** Rhubarb jam and preserves are a delicious way to preserve your rhubarb harvest for later use. The tartness of rhubarb balances well with the sweetness of sugar.
* **Sauces and Chutneys:** Rhubarb can be used to make savory sauces and chutneys that pair well with meats and cheeses. Combine rhubarb with spices, such as ginger, cloves, and cinnamon, for a flavorful condiment.
* **Drinks:** Rhubarb juice, rhubarb lemonade, and rhubarb cocktails are refreshing beverages that are perfect for summer. The tartness of rhubarb adds a unique twist to traditional drinks.
* **Cakes and Muffins:** Add chopped rhubarb to cakes and muffins for a moist and flavorful treat.

## Conclusion

Growing rhubarb is a rewarding experience that can provide you with a delicious and versatile harvest for many years to come. By following these comprehensive guidelines, you can successfully plant, care for, and harvest rhubarb in your garden. Remember to choose the right variety for your climate, provide well-drained and fertile soil, water regularly, and remove flower stalks. With a little care and attention, you’ll be enjoying rhubarb pies, jams, and other culinary delights for years to come.