Rhubarb

Rhubarb

Growing Rhubarb

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Varieties

German Wine, Macdonald, Crimson.

 

Propagation

Healthy, vigorous 3 to 4-year old crowns are divided to obtain two or more buds per seed-piece.

 

Soils

Use a well-drained but moisture-holding soil with a pH of 5.5 to 7.0. The lighter soils will produce an earlier crop but may require irrigation.


Fields to be planted should be plowed deeply and worked in the fall and spring to prevent the weeds from going to seed.
 

Fertilizers

A soil test is necessary to determine phosphate and potash requirements. Use the Vegetable Production Guide: Nutrient Management (PDF) for recommendations based on soil test results.  

Lime should be applied if the pH is below 5.6. Do not apply manure or fertilizer within 2 weeks of the lime application.

Manure at 22 to 45 tonnes/ha (9 to 18 tonnes/acre) may be applied in the fall or as early as possible in the spring.

Fertilizer—In year of setting apply 80 kg/ha (32 kg/acre) nitrogen and the required phosphate and potash.

In subsequent years apply 170 kg/ha (68 kg/acre) nitrogen and the required phosphate and potash.

Fertilizer applications should be split into 3 side-dressings:

  • Before growth starts in the spring
  • After growth starts
  • After harvest

Nitrogen rates may be reduced in the first two years with manure applications.

 

Planting

 Planting is best done in the spring, but may be done in the fall where the soils are not likely to heave because of frost. The seed-pieces are planted 7.5 cm deep, 60 cm apart, in rows about 120 cm apart.

 

Row Covers

The use of plastic mini-tunnels applied over rhubarb in February will increase early yield, but will not affect total marketable yield. Growers may wish to apply covers (not slitted or perforated) over a few rows to establish an early fresh market.

See the “Plasticulture" section of the Vegetable Production Guide: Planting (PDF). 

 

Harvesting

Stalks should not be pulled during the first year of growth. In subsequent years, harvesting can be expected to start toward the end of March and to end in June. This will vary with management practices, with the variety being grown, and with the market demand.

Plants should not be overpulled at any time, as a certain amount of foliage is required for the development of the present crop as well as next year’s crop.

A well-cared-for patch will last for 10 years or longer.

 

Rhubarb Weed Management

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Pre-emergence

Pre-emergence: Herbicide Application Rates
Product Rate PHI* Comments

Sandea

(halosulfuron)

Group 2

 35 to 70 g/ha (14 to 28 g/acre)

Apply in 140 L/ha (60 L/acre)		 60
  • Controls actively growing broadleaf weeds including chickweed, groundsel, ladysthumb, lambsquarters, wild mustard, redroot pigweed, plantain, sheperd's purse and smartweed.
  • Suppresses yellow nutsedge.
  • Make a broadcast application to dormant rhubarb, just prior to the breaking of rhubarb dormancy.
  • Use a non-ionic surfactant if labeled weeds are emerged.
  • Do not apply more than 70g/ha (28 g/acre) of Sandea per season.

Callisto 480SC

(mesotrione)

Group 27

 300 mL/ha
(120 mL/acre)

Apply in 100 to 200 L/ha (40 to 80 L/acre) water at 275 kPa 		42
  • Apply pre-emergent to the crop and pre-emergent up to 2-leaf stage of weeds.
  • Controls lamb's-quarters, redroot pigweed and wild mustard..
  • Caution:  apply to dormant (prior to spring green-up) rhubarb.  Application of Callisto 480SC to rhubarb that is not dormant will result in crop injury.
  • Rainfall or irrigation after application of Callisto 480SC may increase the risk o finjury to emerging rhubarb.
  • Repeated use in low pH soils may cause injury to rhubarb plants.
  • Wait at least 18 months after the last Callisto 480SC application in rhubarb before replanting rhubarb.
  • Do not enter treated area for 12 hours.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

 

Post-emergence

Post-emergence: Herbicide Application Rates
Product Rate PHI* Comments

Venture L

(fluazifop-P-butyl & S-isomer)

Group 1		 barnyard grass (2-5 leaf stage):
0.8 L/ha (0.32 L/acre)

proso millet (2-5 leaf):
1.0 L/ha (0.4 L/acre)

foxtails (2-4 leaf):
1.4 L/ha (0.56 L/acre)

quackgrass (3-5 leaf):
2.0 L/ha (0.8 L/acre)		 14
  • Do not use in greenhouses.
  • Annual bluegrass and broadleaved weeds are not controlled.
  • Repeat using a 14 day interval.
  • Do not apply more than 2 times per season.
  • Apply in sufficient water to ensure thorough coverage.
  • Apply in 50 to 200 L/ha (20 to 80 L/acre) water at 200 to 300 kPa.
  • Apply using 425 kPa pressure for dense weed infestations or dense crop canopies.
  • Warning: Women capable of bearing children should avoid exposure to Venture.
  • Observe a plantback interval of 12 months for crops not listed.
  • Do not re-enter treated area for 12 hours.

Aim EC

(carfentrazone-ethyl)

Group 14

 37 to 117 mL/ha
(15 to 47 mL/acre)

Apply in 100 L/ha (40 L/acre) of water		 1
  • Controls annual weeds.
  • Must be applied using hooded sprayers to weeds between the rows of the emerged crop.
  •  Use an adjuvant such as Agral 90 or Agral-Surf at 0.25% v/v (0.25 L/100 L of spray solution) or Merge at 1% v/v (1 L/100 L of spray solution).
  • Precaution:  crop injury will occur when spray drift is allowed to come in contact with green stem tissue or leaves.
  • Apply only once per growing season.

*PHI = Pre-harvest interval
BUFFERS – Refer to product label for buffer requirements, and consult the Vegetable Production Guide: Pesticide Regulations and Safety (PDF).
PESTICIDE GROUP DETAILS – see the Vegetable Production Guide: Pesticide Toxicity Table (PDF).

 

Rhubarb Disease Management

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Nematodes

Nematodes are microscopic worms which feed on plant roots and crowns. Infected plants are stunted with thin, narrow stalks. Plants seldom die but yields are greatly reduced.

Control

Before establishing new plantings, especially following berry crops or rhubarb, collect soil samples for nematode analysis. Fumigation may be required.

 

Ramularia Leaf and Stalk Spot

Conspicuous leaf spots appear early in the growing season. Under wet conditions, spots may appear on stalks reducing quality or making them unmarketable.

Control

Clean-up crop refuse at end of harvest by rotovating to encourage rapid breakdown.

 

Virus Disease

Rhubarb, being a perennial, vegetatively propagated-crop, is vulnerable to virus infection. Fortunately, plant to plant spread is usually quite slow in British Columbia.

Virus-infected plants are usually smaller than nearby healthy plants and the leaves often have distinct mosaic or ring patterns.

Control

In establishing a field, obtain healthy planting stock, or if doing your own propagation, select only the most vigorous- appearing mother plants. Rogue out and destroy plants with virus symptoms as they appear in a field.