Sowing seed and planting crowns (roots): Rhubarb is a perennial plant that can grow for 10 to 15 years or longer. Rhubarb can be grown from seed or crowns. If you grow rhubarb from seed, your first harvest will come in 3-4 years. If you grow rhubarb from crowns (established roots), the first harvest will come a year after planting two-year-old crowns and two years after planting one-year-old crowns. Crowns are available in nurseries and garden centers each spring or you can start your own. To start plants from seed, sow seeds indoors or outdoors in early spring one year before re-setting the roots in their permanent location. Soak the seed in water for a half day before sowing. Cover seed with ½”(12 mm) of soil. Seed will germinate in 10 days at 72°F (22°C).
Growing: Grow rhubarb in deep, loose, well-drained soil rich in organic matter and compost. Choose a location that gets at least 6 hours of sun each day. Set rhubarb crowns (roots) in the garden as early as the soil can be worked in spring. Plant one- or two-year-old crowns 1″ (2.5 cm) deep on raised mounds 6-9” (15-20cm) high and 36” (91 cm) apart. Plant the crown bud side up and firm the soil around the crown. Plant in autumn after summer heat has broken. Plants will emerge in about 6 weeks. Keep the soil evenly moist throughout the growing season; do not water during the winter. Mulch the planting with straw or leaf much during the winter to protect roots from freezing temperatures. Regular applications of compost or well-rotted manure will keep plants productive.
Harvesting: Let rhubarb grow for two seasons before harvesting in the third season; harvest leaf stalks for 4-5 weeks in spring; older plants can take 8 weeks of harvest. Do not eat rhubarb leaves which contain poisonous concentrations of oxalic acid. Harvest when leaf stalks are 1” (2.5 cm) or more in diameter and stems are about 24” (60 cm) in length. Grasp each stalk near the base, pull outwards and twist sideways; leave a few young central stalks to replenish the crowns. Rhubarb will keep in the refrigerator for 2-4 weeks; remove leaves first. Rhubarb cut and blanched will keep in the freezer for 3-4 months.
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