These instructions outline how to plant and care for young rhubarb plants.  If you wish a deeper understanding about growing rhubarb, visit Growing Rhubarb.

Rhubarb is an adaptive and robust plant.  It will grow in many conditions, except hot weather or constantly wet soil.  This describes how to maximize the yield and quality of your rhubarb.

BEFORE PLANTING

  • Before planting, prepare an area 3’ in diameter and 1.5-3’ deep, depending on the variety. Green varieties, particularly Victoria, are larger and benefit from deeper soil.  Be sure the soil is
    • rich in organic material (we mix at least 3-4 inches of mature compost into 6” dense soil, then mound it 3’ high and fill between mounds with 3’ of pine mulch);
    • has good drainage, avoiding
      • low areas where water accumulates or runs
      • areas near or inside lawns or other frequently watered areas
      • soils with high clay content (Google how to test for this yourselves. It’s easy.)
      • areas bounded by clay or hardpan. Do not dig a clay bowl in clay soil.  Consider raised beds where you plant at least 2-3’ from the edge, depending on variety.
    • If dry root, plant vertically with the top just below the surface.
    • If potted plant, disturb the potting soil as little as possible.
    • Create a water ring (dam) of pure mature compost with a diameter of 12 inches around the root. This allows you to flood the area and deep water the plant
  • Fill the water ring with water, a gallon or two at least.

PLANTING FROM SEED

  • Rhubarb plants are seldom perfectly true-to-type when started from seeds.  Meaning, they will not be identical to the plant from which the seed was harvested.  Therefore, it is a good idea to plant several seedlings 6-12″ apart where you want to eventually have one good plant.  Cull those seedlings annually, leaving only the most desirable plants.
  • Seeds can be started indoors or outside, in the intended growing site.  If starting indoors, plant seeds in a tray of starting soil/mix about 1/8″ under the soil.  Keep wet until the seeds germinate.  Keeping the soil warm (e.g. 70 degrees F) will speed germination.  Two dicots will first appear…not true rhubarb leaves.  Be sure the tray is in sunlight or under grow lights when this happens.  Transplant the plants to either pots or their final destination once the first true rhubarb leaf appears.  If not started in sunlight, the plants must first be hardened to sunlight before planting outside.  Gradually expose them to more and more sunlight over a 2-3 week period until they are happy in full sun during daylight hours.

PLANTING FROM POTS

  • Unlike many plants, it is best to disturb the rhubarb roots as little as possible when transferring from a pot to the ground.
  • Be sure the plant has been hardened off to sunlight before putting it outside.
  • Water the plant to keep the soil moist for the first week.  Deep water the plants to ensure the roots go deep and the plant becomes more drought tolerant.  One way to do this is to build a water ring of compost or soil around the plant and fill that completely with water each time you water the plant.

AFTER PLANTING

  • In the first year, water when top three fourths inch of soil is dry. Roots should not be kept wet.
  • In the years after planting such frequent watering is not necessary. The roots should not completely dry out but they need to dry enough for air to return to the soil between waterings.
    • Fertilize twice a year, watering each time (rhubarb is a heavy feeder) Best fertilization is based on soil test. Fertilize
      • once when the plants first emerge from their winter sleep
      • once again after the first harvest
    • Water the two times above even if not using chemical fertilizer.
    • We water our plants via hose/water-ring, and they get watered at most 6 times per year, 3 times per year prior to recent draught and hot weather.
  • Avoid early or excessive harvesting. For the healthiest plant and largest future harvests the roots must enlarge and establish themselves before you begin harvesting.  Each time you pick a stalk you cause the plant to put energy into replacing that stalk instead of growing more root.  Best not to harvest at all until the third year of growth, when the plant has been in the ground at least 2 years.  Then, harvest at most ½ of the biomass until the plant reaches the size you want.  Harvest stalks by pulling them rather than cutting.  Cut flower stalks at their base as soon as they appear.