I planted 2 Dogwood and 2 Red Bud trees in my front yard about 2 months ago. I am having all sorts of problems out of them. With the Dogwood's the leaves are curling up and then turning brown. With the Red Bud's the leaves are turning yellow and then drying up and falling off. I have used fertilizer spikes and watered them regularly. Does anyone know what is happening?

When you think of dogwoods, you probably think of Cornus florida, our native flowering dogwood. You know the one-it flowers in April or May. It a great showy plant in part because the flowers open before the leaves start to come out, enhancing the effect.

The flowering dogwood has also been very popular in our landscapes because it is a slow growing, small tree varying in height from 20 to 40 feet at maturity depending on location, with an equal spread, so it fits very well into the typical suburban lawn. The growth habit of the flowering dogwood also provides interest because its crown becomes flat topped with age, creating a layered effect in the winter landscape.

But the flowering dogwood has had its fair share of problems over the last few years. It suffers from a disease called anthracnose that weakens stems and twigs. Anthracnose starts with purple leaf spots that turn into large tan blotches. Affected leaves will dry up on the stems and may just hang on and on. Even after normal leaf drop. The anthracnose disease is caused by a fungus named Discula destructiva-its aptly named because trees under stress may only survive 2 or 3 years. This is a truly significant problem and is one of the reasons that nursery industry professional recommend that trees not be transplanted from the wild.

Powdery mildew is another disease that has caused a great deal of problems with dogwoods. Powdery mildew also starts with leaf spots-this time a reddish color; the spots develop into dead brown areas on the leaf. Powdery mildew is often obvious on other plants because of the white coating that it produces on the leaves, but this isn’t always the case with dogwood trees, although sometimes you will see that telltale white stuff on newly formed leaves. More often than not, you’ll walk out to your garden one day and notice that your dogwood tree looks awful-the powdery mildew will have taken over.

So what can you do about these dread diseases? First plant resistant varieties. Trials have shown that the variety ‘Cherokee Brave’ (red), ‘Spring Time’ (white) and ‘Pygmaea’ (white) have resistance to powdery mildew. Secondly, choose the right site for planting. Even though dogwoods are understory trees, they will benefit from a planting site that allows them a good dose of morning sun to dry leaves.

You’ll also need to avoid cultural practices that will produce succulent plant growth: don’t fertilize with high nitrogen fertilizers, don’t prune heavily, and don’t water excessively-give your dogwoods a long ground soaking (water the root system, not the crown of the plant) when Mother Nature doesn’t provide rain for two weeks, you don’t want your dogwoods to suffer from drought, but you also don’t want to give them frequent light waterings.

Alternatively, use good cultural practices to encourage healthy plant. Mulch over the root system, remove any damaged or dead branches promptly, encourage air movement and light penetration through the plant by lightly pruning your tree—or other plants nearby that might be crowding your dogwood, rake away any fallen leaves to prevent further spread of the disease.

There are fungicides that will control powdery mildew, ask at your local garden center for recommendations. Spray programs need to be started at the first sign of bud break, and continued according to label directions for good control. Keep in mind that fungicides will not eliminate disease, they will only control the further spread of disease.

Some dogwood cultivars are more reliable bloomers; others are more resistant to disease problems that will keep them healthier and blooming better. And often, when a dogwood has a strong bloom year, the following year will be weaker. Keep your dogwoods as stress free as possible and they should perform well for you year after year.

Thanks for the response Cindi! However, I am thinking that the leaves on both my dogwood and red bud trees (that I bought from Lowe's 2 months ago) are turning brown due to the fertilizer spikes that I put in the ground when I planted them. I put the spikes 6 inches away from the stem and I am thinking that was too close and has caused fertilizer leaf burn. So, about 1 week ago I dug the trees up, changed out the dirt, and gave the hole and tree roots a very good soaking with water to see if it would help. I haven't noticed the tree leaves reviving any. Do you have any suggestions on how to revive my trees if indeed it is due to over-fertilizing? Thanks.

Just keep watering to help leach out/dilute the fertilizer.