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The Homeowners Column

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Rhubarb and Asparagus – Perennial Favorites

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Sandra Mason
State Master Gardener Coordinator
slmason@illinois.edu

Tomatoes, green beans and spinach are just a few of the many vegetables we must replant each season to reap our harvest of plentiful produce. However asparagus and rhubarb are perennials that magically materialize each spring to reward your initial planting efforts.

Rhubarb and asparagus deserve a spot in the garden with decades of harvest in mind. Both require full sun and well-drained, compost rich soil. Consider raised beds or even a spot in the flower garden. Rhubarb is especially prone to root or crown rots in wet soil.

Asparagus and rhubarb are planted as crowns or roots in spring. Existing rhubarb can also be divided in early spring while plants are dormant. Rhubarb may also be purchased as container grown plants.

Popular rhubarb cultivars with red leafstalks include: 'Canada Red'; 'Cherry Red'; 'Crimson Red'; 'MacDonald'; 'Ruby' and 'Valentine'. 'Victoria' bears green leafstalks.

Plant rhubarb roots with the crown bud 2 inches below the surface of the soil. Do not harvest rhubarb during the first year of planting to allow plants to develop strong roots. Stalks may be harvested for 1 or 2 weeks during the second year and for the full harvest season of 8 to 10 weeks starting the third year.

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To harvest rhubarb, pull the leaf stalks (petioles) from the plant and remove leaves. Rhubarb leaves contain large amounts of oxalic acid and should not be eaten. The best quality leaf stalks are harvested in early spring. Large, older stalks can be tough and stringy. To keep rhubarb plants vigorous, harvest just one third of the leaf stalks at any one time.

Worthy asparagus cultivars include: 'Jersey Giant', 'Jersey Supreme', 'Jersey Knight' and 'Jersey King'. 'Purple Passion' produces a plethora of plump purple spears.

To plant asparagus, place the octopus-looking crowns in a trench 12 to 18 inches wide and 6 inches deep. Crowns should be spaced 9 to 12 inches apart in the trench. Spread the roots outward with the buds of the crown facing up. Cover the crown with 2 inches of soil. As the stems grow add more soil over the crowns. This planting process allows deep planting without forcing the plant to grow through 6 inches of soil at one time.

Asparagus takes some patience. It can be harvested the third year after planting, but limit harvest to one month then let stems grow. After the third year spears can be harvested through June. To harvest asparagus, grasp 5 to 8 inch long spears at the base then bend them toward the ground. Spears will snap where stems are tender. If not eaten immediately, asparagus should be stored upright in glass of water in refrigerator.

Rhubarb and asparagus have few problems. With rhubarb we often get questions about what to do after a freeze or after flower stalks are produced. If rhubarb plants experience a severe freeze, any damaged stalks should be removed and placed in the compost pile. Damage appears as wilted or water soaked leaves and accompanying leaf stalks should not be eaten. Any stalks produced later or showing no damage may be eaten.

Sometimes rhubarb plants produce flower stalks during the spring and summer. Pull and discard flower stalks from the base of the plant as soon as they appear. Leaf stalks can continue to be harvested after plants produce flowers.

Weeds can be a problem in asparagus beds. Hoeing shallowly and hand pulling weeds in very early spring are best solutions for weed control. An old gardener's tale is to apply rock salt to the asparagus patch to keep grass seedlings from germinating. It may work, but may also effect asparagus growth. If you want to use salt on your asparagus, wait til it's on your dinner plate.

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