My rhubarb has not performed as well as it used to. I put homemade compost on it each year and the plant grows okay, but then some of the green leaves wilt or get reddish brown spots. I would like to know if it’s natural process, from the relentless sun or if it’s a disease?
Rhubarb prefers nice, rich, organic, free draining soil in a spot that gets full sun. Firstly consider the age of the rhubarb plants in your garden - the average lifespan of rhubarb is 3-5 years. Plants should be reasonably young and vigorous, and if they are not, consider refreshing your rhubarb patch with new plants. Remember, new plants need to get established so don’t pick the stems for the first year, and start harvesting from the second season.
Rhubarb is a heavy feeder so mulch regularly with Daltons Organic Compost. In early spring and autumn, feed plants with Daltons Organic NuFert and work it into the surrounding soil. It will provide a slow release of nutrients.
If rhubarb plants do dry out, they will collapse very quickly, and the reddish brown spots and green leaf wilting you describe may be a symptom of this. Rhubarb requires regular deep watering during hot, dry Canterbury summers, finished with a good layer of mulch on top. Mulch helps water retention during hot summer days and stops plants from drying out.
TOP TIP: Only eat the stems; the rhubarb leaves are highly toxic so don’t feed them to animals (or humans!). Instead pop them in the compost bin.