Are your rhubarb stems pithy? This often happens at the end of the season, but ours started the growing season with pithy stems and sickly leaves. Having originally planted the rhubarb in Alberta in 1977, moving it from acreage to acreage there and then transplanting it in B.C., it has been a faithful and giving source of beauty and food. How surprised we were to see “old faithful” start to decline. After sourcing a probable cause for the problem, we found there were some things we were doing wrong. Over the years we were mulching with heavy compost material and covering the crown of the plant. This may have caused crown rot, a fungus disease that attacks established clumps of rhubarb. It also needs good drainage, a sunny spot and dividing every 5-10 years. To attempt to remedy the situation we dug it up, divided and discarded part, and the remainder planted in a raised bed. New growth has started so we have visions of rhubarb pie possibly next year!
Questions and Answers
How do I prune my spindly rhododendrons?
Pruning can be done to correct the shape, remove old or dead wood, thin for better air flow and sunlight penetration and to invigorate flowering and new growth. If rhodos could be pruned before leaf growth in the spring, the pruning would be much easier. Since pruning has to take place shortly after flowering has finished (they bloom on previous year’s wood), we are out of luck there. Prune back to the shape and height that is desired, remembering that the new growth will add more height and width to the resulting plant. Using a sharp tool reduce the height of the plant by making a cut at a slight angle just above a node or bud. To cut the side branches or for thinning cut at a slight angle or parallel and approximately 1 inch from the main stem from which it is growing. From what I have read some rhodos do not respond well to severe pruning. Although there is no list of those that don’t appreciate it, a show of ‘pimpled’ green dots on the stem/stalk of the plant, shows it is a candidate for hard pruning. Now I have to look at our rhodo that was cut to one inch above the ground in front of the electrical box by B.C. Hydro. We moved it to the back yard two years ago. It is now 4 feet tall and had its first huge pink flower. Lovely! After pruning a feed of rhodo and azalea fertilizer with a high nitrogen content, such as 30-10-10 and a good watering should result in lovely blooms for next year.
Do I need to remove the spent flowers on the rhodos?
This is an often asked question. It definitely improves the appearance for the rest of the growing season. There are two schools of thought: one, that it is not necessary as far as plant growth, and the other, that it leaves only one stem of new growth making the plant spindly. Also, energy is put into making seeds instead of new growth and next year’s flower buds. Often a rhodo is so large that it is impossible to deadhead anyway. Since we have always removed the spent flowers, I have no experience with leaving them on.
Please continue to submit questions or comments to firstname.lastname@example.org