Propagating dogwood seeds - Ask Extension
For 3 years I have collected drupes from the beautiful dogwood in my front yard and created seedlings (soaked drupes, embedded seeds in peat moss, kep...
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Propagating dogwood seeds #879236
Asked July 29, 2024, 12:49 PM EDT
For 3 years I have collected drupes from the beautiful dogwood in my front yard and created seedlings (soaked drupes, embedded seeds in peat moss, kept in fridge). I am able to create seedlings, but at a certain stage, they wither and die, despite watering. Attached are photos of one healthy and one dying plant, started from the same batch. What can I do to keep them growing?
Montgomery County Maryland
Expert Response
Are the seedlings put outside, or kept indoors? Indoor conditions may be stressful on the seedlings, with less light, airflow, humidity, and other conditions helpful to their development. Are they potted in garden soil or potting soil? The former can hold pathogens and be too slow-to-drain, while the latter would be ideal, at least while they are still in a container (as opposed to being moved into the ground).
It's hard to see the symptoms clearly on the wilted plant, but the foliage on the plant labeled as healthy appears to be afflicted with powdery mildew, a very common pathogen outdoors (and sometimes indoors, especially if garden soil was used in the pot). Flowering Dogwood can be particularly vulnerable to this infection, which is one reason why growing cultivars instead of the straight species can be advantageous, as they have been selected to be more resistant to mildew outbreaks. (Cultivars will not come true from seed.) Soil-borne pathogens that can cause root rot or stem rot might be responsible for the collapse of the other seedling, it's hard to tell. Dogwoods aren't highly drought tolerant, preferring to stay evenly moist, but soil drainage must be excellent, and if the roots stay too wet, they may succumb to rot from the oxygen depravation.
If you haven't yet, try germinating the seeds outdoors after their winter dormancy (either keeping them outside and "winter sown" for that dormancy requirement, or after taking them out of the fridge). An exposure of about half-sun/half-shade may work well to give them enough light for good growth while shielding them from the brunt of too much direct summer sun.
Miri
It's hard to see the symptoms clearly on the wilted plant, but the foliage on the plant labeled as healthy appears to be afflicted with powdery mildew, a very common pathogen outdoors (and sometimes indoors, especially if garden soil was used in the pot). Flowering Dogwood can be particularly vulnerable to this infection, which is one reason why growing cultivars instead of the straight species can be advantageous, as they have been selected to be more resistant to mildew outbreaks. (Cultivars will not come true from seed.) Soil-borne pathogens that can cause root rot or stem rot might be responsible for the collapse of the other seedling, it's hard to tell. Dogwoods aren't highly drought tolerant, preferring to stay evenly moist, but soil drainage must be excellent, and if the roots stay too wet, they may succumb to rot from the oxygen depravation.
If you haven't yet, try germinating the seeds outdoors after their winter dormancy (either keeping them outside and "winter sown" for that dormancy requirement, or after taking them out of the fridge). An exposure of about half-sun/half-shade may work well to give them enough light for good growth while shielding them from the brunt of too much direct summer sun.
Miri
Hi Miri,
Thank you very much for the advice! I believe you are correct about the powdery mildew. I have some Neem oil so will try that.
Didi
You're welcome.
Neem oil is not always a reliably effective fungicide, but if the plants are inside, you won't have much choice since few fungicides are labeled for indoor use. The saplings need to spend winter outside so they experience the required cold dormancy for them to regrow properly in spring, so you can start transitioning them to outdoor conditions soon, if you haven't already. Once outside, depending on pot size, they will need regular/frequent monitoring for watering needs, since pots dry out quickly, and put them into a shady spot to acclimate, since they are not yet used to direct sun. (Sun through a window is weaker than direct exposure outside.) Additionally, if re-treatment with a fungicide is needed once the seedlings are outside, do not spray while temperatures are above 85 degrees, or foliage injury may result.
Miri
Neem oil is not always a reliably effective fungicide, but if the plants are inside, you won't have much choice since few fungicides are labeled for indoor use. The saplings need to spend winter outside so they experience the required cold dormancy for them to regrow properly in spring, so you can start transitioning them to outdoor conditions soon, if you haven't already. Once outside, depending on pot size, they will need regular/frequent monitoring for watering needs, since pots dry out quickly, and put them into a shady spot to acclimate, since they are not yet used to direct sun. (Sun through a window is weaker than direct exposure outside.) Additionally, if re-treatment with a fungicide is needed once the seedlings are outside, do not spray while temperatures are above 85 degrees, or foliage injury may result.
Miri
