Hi, I have tried several different years to grow rhubarb. I've bought healthy root stock, planted it in my garden and had a healthy looking plant come up. But then, every time, the plant wilts and succumbs quickly to something that seems like a virus. The stems rot away from the plant and the whole thing just wilts and dies in a matter of days. I tried one year growing rhubarb in a fresh pot with potting soil, and the same thing happened. What can I do to ensure that when I try again this year, the plant won't suddenly die? thanks, Megan
Prince George's County Maryland
Rhubarb is unfortunately difficult to grow in our area. They prefer to be cooler than our summer temperatures allow, and our heavy compacted soils promote root rots. If you wish to try again, there are several tactics to try to meet with success:
- switch suppliers; if you have been mail-ordering or using a local garden center (or a specific brand, if sold as pre-packaged bare roots), use a different source in case those plants either aren't maintained well in storage or are cultivars more easily stressed by environmental conditions
- try growing them in a site that receives some light shade during the hot afternoon hours; although rhubarb can prosper in full sun, our combined heat makes this too stressful for them, and stress can lead to opportunistic infections
- if you have a friend with a thriving clump of rhubarb, see if they can provide you with a division; their plant may be more well-adapted to local conditions or, being older, may be more robust and resilient than younger root pieces commonly sold as starter plants
- if growing in the ground, try using a raised bed to aid in drainage; if growing in a container again, your approach with fresh pots and fresh potting soil is good, but combining this with the above changes may prove successful. In addition, if you feel the potting soil stays wet for too long, try another brand or mix in more perlite, which aids in aeration.
Rhubarb likes moisture-retentive soil during dry weather but can be prone to rot when wet. Therefore, only water the plants when they are sufficiently dry: before wilting, but when the top few inches of garden soil (or couple inches of potting soil) has dried. Unglazed terra cotta pottery, when moist, might help via the evaporative cooling effect is has. Keeping the clay moist while not over-watering the soil, however, may be challenging.