Dahlias, especially needy this year, are worth every bit of effort

There’s no doubt about it, dahlias define my garden at this time of year. As they come into bloom, they provide punches of color that few other plants could manage right now. But even I, an admitted dahlia addict, will admit that they aren’t the easiest plant to grow. And this year has been a particularly trying year.

Dahlias have a specific set of needs — rich but well-draining soil, consistent water and at least part sun. Take away any part of that recipe and dahlias will let their displeasure be known.

The consistent moisture part of the equation has been particularly challenging this year. During the time that dahlias were developing most of their leafy growth, there was almost no rainfall in the area. Of course supplemental watering helps, but it can be a challenge to water enough to get proper moisture back in the soil.

Then there was a string of hot, humid days with little cooling at night, another condition that dahlias aren’t fond of.

If there was a year for something to go wrong with dahlias, this was probably it.

The extended dry period seems to have led to weak stems. I’ve had to stake almost all my dahlias this year, even some shorter varieties like ‘Crichton Honey’ that usually manage to hold themselves upright.

And insects like nothing more than an already compromised plant. So in addition to the Japanese beetles, spider mites, thrips and even cucumber beetles, which also favor dahlias, have been on the attack.

If that wasn’t enough to make dahlia-growers throw up their hands, there’s also the powdery mildew to contend with. This is the first year in at least a decade that I can remember having a powdery mildew issue, undoubtedly brought on by a stressed plant contending with prolonged high humidity.

Fortunately, all is not lost. Many insect issues can be handled by judicious hand-picking or less invasive sprays like Neem oil or BT spray. Powdery mildew is more difficult to manage, requiring a fungicide application. If only the lower leaves are affected, I just pull them off.

I don’t do much in the way of fertilizing dahlias because I trust my “feed the soil” ethos to do most of the heavy lifting, but an occasional application of liquid seaweed fertilizer seems to keep them producing.

But in order to “keep” flowering, they need to start flowering, and that is the No. 1 complaint of dahlia growers —  “Why aren’t my dahlias flowering yet?” The answer is simple, although perhaps unsatisfactory. Some dahlias just take longer to get going, especially the large, so-called dinnerplate varieties. My only advice is to be patient. Dahlias are late-season stars, and once they start blooming, they’ll keep it up until frost, so long as you faithfully remove spent flowers.

Add up all the quirky needs of dahlias and you might wonder why anyone would bother with them. One look around a late-summer garden overflowing with dahlias in full bloom and any gardener will know they are worth every bit of trouble.