Camellia and Forsythia bushes

Asked May 15, 2020, 10:52 PM EDT

I have 2 camellia bushes next to each other. They are mature, and almost reach our gutter. One is suffering from soil that is too wet. The leaves have turned yellow this season and many have fallen off. It hardly produced any flowers this season. The one next to it suffered only a little and still produced flowers. My question is: What do I do to bring them both back to life? We are working to check for a leak in the downspout next to the sick one. We are wondering if we should prune it way back? We also have acid-loving fertilizer to put on them, Chelated Liquid Iron, as well as Holly Tone plant food for acid-loving plants to work into the soil once it is drier. What would you suggest? I also would like to know how to prune my Forsythia that suffered when we had a large Douglas fir cut down next to it. Not sure if you can help without seeing these plants, but would appreciate anything you could do to guide me. Thank you so much!

Benton County Oregon

1 Response

Hello. Fix the drainage of the soil around these plants. Fix the drain spout leak and install a French drain to take water away from the area in general. Check irrigation lines for leaks also. I think that your camellia is suffering from Phytophthora infection that is causing root rot. It is caused by too wet soils that allows the roots to be impacted and can cause the death of shrubs and trees like your camellia. The leaves turn yellow not because there is not enough nutrition in the soil but because the roots are compromised to the point of no longer being able to take up those nutrients and send them upward. It usually means that the roots of the plant are subjected to standing water for a period of time. Inundation allows the disease to invade the root system. This disease is very motile in wet soils and I fear you may start to see symptoms in the neighboring shrub also unless you take action to fix your wet soil issue. If the plant on the left dies build up the flower bed above the current grade level into a raised area before planting a replacement. Phytophthora is ubiquitous in our soils in the Willamette Valley. Many plants are susceptible to it.

Forsythia shrubs can be difficult to prune depending on how long it has been since its last trim. I am going to guide you to the book that is considered the ‘go to’ book on pruning in the Pacific Northwest. The author has dedicated several pages to Forsythia complete with diagrams and explanation which are way too long to regurgitate here. I believe you will find it at a local library or bookstore. The author is Cass Turnbull. The title of the book is, “Cass Turnbull’s Guide to Pruning”, (What, When, Where and How to Prune for a more Beautiful Garden.)

https://extension.oregonstate.edu/sites/default/files/documents/12281/pruningtreesshrubs.pdf From Oregon State extension gives a very brief but good run down on generic pruning. Included is a table that tells you when to prune flowering shrubs. If you cannot access the book in time use your own judgement. Basics of pruning include. Remove dead materials. Remove crossing branches. Remove diseased material. Do not remove more than 1/3 of the canopy of the shrub. Start there and start more specific forsythia pruning next year.