Brown Leaves On Osmanthus Heterophyllus - Knowledgebase Question

Bowie, MD
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Question by terrapinmar
December 14, 2002
I recently planted an osmanthus heterophyllus (false holly), and the leaves are starting to turn brown. When it was planted, the leaves were a varigated green and yellow, but we have had an early winter and the weather turned cold within two to three weeks of planting. Does the false holly typically die back in the winter? The bottom portion of the holly is still green, but as you go to the top of the plant, the leaves are much more yellow and some of the yellow leaves are turning brown. I am not sure if I should wait out the winter and hope for the best, or if there is anything I can do during the winter to help the plant get established and not die.

Thank you

Answer from NGA
December 14, 2002
This plant is a broad leafed evergreen and should not be browning to the extent you described. It may discolor a bit in winter when planted in full sun, but it would not be extreme.

Most commonly, browning can be a sign of transplant shock, poor planting technique/location (eg if encircling roots were not loosened, if the plant was set too deeply, if the site is inappropriate, etc.), overwatering or underwatering, or winter stress from wind and sun. Late season fertilizing could also have caused overly succulent growth and late growth that would suffer in cold weather due to a lack of hardening off time.

I am assuming you purchased a plant intended for the landscape rather than a small one intended as a table top decoration. If you have one of these florist-type trees, it is probably just very stressed and may not survive.

Based on your description, I think the plant is drying out thus causing the foliage problems. If it suffered somewhat during the dry summer and early fall, some of that stress would be becoming apparent now.

Also, a newly transplanted shrub is vulnerable to drying out due to the relatively small and unestablished root system. This plant generally requires an evenly moist yet well drained soil during the growing season and would also need to be well watered throughout the fall -- especially in a dry year -- with an eye kept on watering in general. You want the plant to go into winter well hydrated because it continues to lose moisture through its foliage all winter.

On the other hand, overwatering can deprive the plant roots of oxygen and this can also cause browning, although usually not quite in the pattern you described. The best way to tell if you need to water is to dig down into the soil and check with your finger. Then water thoroughly but not to the point where the soil is sopping wet. After watering, wait several hours and suffered damage along the way then this could cause systematic yellowing and drying from the damaged point upward. If you find mangled branches, trim them away cleanly at the damaged area. If the other is a possibility, then you can wait and see if it can manage to leaf out in the spring. If not, trim it back then, cutting to good live wood.

There are a few things you can try in addition to watering if you think the plant has dried out, these would also be good TLC measures: shade the plant, spray it with anti-dessicant spray (available at garden centers, read and follow the label instructions), and create a wind break for it if it is in a windy location.

Finally, be patient with it and see how it fares next spring. The dried out portions may leaf out again. If not, trim the plant back to healthy wood and certainly trim out any that may die off during the winter. Dead twigs or branches will show no green inside, live wood has a layer of green inside the bark.

This plant would be considered marginally hardy in your area, so I would suggest folowing the TLC measures each year at least for the first few years while it is becoming established, especially if it is planted in anything but an extremely well-sheltered location out of the wind -- meaning a warmer microclimate.

I hope this helps you trouble shoot. Good luck with your Osmanthus.

then dig down again and see how effective your watering was (or wasn't.)

You would also want to use several inches of organic mulch over the root area year round to help keep the soil moisture level constant. The mulch will also help add organic matter to the soil when it breaks down over time.

This is another important factor in the health of this plant, it needs a nice organic, humusy soil. If it is planted in heavy clay this may be a problem in that clay is not a well drained soil. Clay can also create a bowl effect at the bottom of the planting hole, causing water to collect there because the clay drains more slowly than the original potting mix around the plants' roots. Conversely, clay can be slow to rehydrate once it has been allowed to dry out. Planting in a low spot that is poorly drained could also cause excess water to collect around the roots.

If your plant was allowed to dry out and now the ground is frozen, it will not be able to absorb moisture through the roots. This means watering now would not help if it can't soak in. If it is not frozen (sometimes you can chip through the top frosted layer) you can look into the watering -- and keep it in mind all next season and through the fall.

Next, this plant requires an acidic soil. The soils in your area are usually naturally acid enough, however soil amendments such as lime and occasionally purchased top soil or similar materials can sometimes be alkaline and raise the pH out of the acid range. I would suggest you run some basic soil tests and see where you are in terms of pH for that reason. Work with garden center personnel or your county extension to interpret the results. The wrong pH can cause yellowing, so it is worth looking into.

Next, if the plant was brought home in an open vehicle the journey could have caused part of it to dry out beyond rehydrating, or if the branch framework

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