When To Stop Harvesting Rhubarb And Why Summer Rest Matters

Rhubarb plants can become affected with many diseases. Rhubarb crown rot, caused by Phytophthora, is often encountered during commercial production but rarely seen at home gardens.

Rest and recharge this summer by enjoying long walks without your phone, reading for pleasure or simply sitting still and watching the birds fly by.

Spring

Rhubarb thrives best when planted in full sun with rich, well-draining soil with an ideal pH between 6.0 and 6.8, featuring plenty of organic matter for its roots to feed on. An inch or two of well-aged compost or manure added at planting time in spring should help the ground warm more rapidly before you fertilize as required by crop specific soil testing for best results.

Thin, spindly stalks indicate stress caused by temperature, low fertility or overcrowding. Flower and seed stalks should be snapped off immediately as they reduce vigor and hinder leaf stalk growth; crown rot may occur from poor drainage or excessively moist conditions; overcrowded plants require division after 8-10 years or two-three years, depending on climate conditions.

To prevent root rot, it is best to grow rhubarb in places prone to waterlogging or frost damage, and prepare the site by clearing away perennial weeds before planting. Consistent moisture levels throughout spring-fall should also help ensure its success.

Summer

Rhubarb plants should be watered throughout the summer to maximize yield and help store up food reserves for next year’s harvest. Watering once every seven to ten days usually suffices.

Keep the leaves off the table, as they contain oxalic acid that may cause mouth lesions. Only consume stalks as food sources.

Older rhubarb plants may produce seed stalks, which should be cut and discarded as soon as they appear. Producing too many seed stalks reduces plant vigor and inhibits leaf production; causes of seed stalks can include infertile soil, excessive heat or cold, drought conditions or old age.

Rhubarb plants should be mulched heavily to conserve moisture and control weeds, with an inch or two of organic matter such as compost or well-aged manure added in springtime to the soil. A soil test should be run in order to ascertain specific fertilizer needs; adding fertilizer directly onto the crown could result in disease outbreak.

Fall

Rhubarb is an avid feeder that benefits from regular fertilization. Applying a balanced fertiliser such as Plantura All Purpose Plant Food 5-5-5 every spring increases nutrient availability for healthy growth.

Mulch (3-4 inches thick) can help suppress weeds, conserve moisture and add organic matter to the soil. However, take caution not to cover rhubarb crowns as this could lead to crown rot.

Flower stalks that form can rob precious energy from rhubarb plants and should be pruned as soon as they appear in order to reduce disease potential, particularly from Phytophthora. This will also lower disease risks significantly.

After the current season’s leaves have softened and died back, it is time to divide and dig up your rhubarb plants. Ideally this should be done early spring; for new beds you should amend the soil with garden compost or well-rotted manure prior to digging up and dividing clumps by carefully breaking each crown into fist-sized pieces, leaving some roots attached as you do so.

Holidays

Harvest season for rhubarb typically runs from mid-June through August, as continuing harvest into summer weakens rhubarb plants and reduces next year’s yield. Cutting stalks down to their bases speeds wilting and eliminating grassy or large-stemmed weeds near planting sites helps control rhubarb curculio, an insect which punctures leaves of rhubarb plants with its large, rusty snout beetle whose holes punctures leaves punctures rhubarb plants snout beetles that punctures leaves puncturing its leaves puncturing its leaves puncturing its leaves puncturing them from within its core.

Check your rhubarb plants periodically during spring for signs of cold damage, which will include damaged foliage and stalks that shrivel and turn brown or black in appearance. Any plants affected should be pulled up and composted immediately.

Rhubarb grows best in well-drained soils that are rich in organic matter and receive six to eight hours of sun per day, as this maximizes yields. Annual nitrogen (N) applications help ensure vigorous plants with heavy yields – broadcast and work nitrogen into established rhubarb plants in early spring before growth commences; an application just prior to harvest can also prove helpful.