How green are my dahlias?

I planted some dahlias in the past month only to see the leaves turn yellow. I learned that this can happen with too much watering or not enough nitrogen or a fungus in the dirt. None of these seemed to apply. In fact, a dahlia from last year that weathered the mild winter, is perfectly green and healthy looking. It's in the bottom right corner of the second photo. I took these photos to the nursery where I'd purchased the plants. They offered to give me new plants, but theirs also had yellowing leaves. They then offered to refund the price or give me other plants.

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I opted for new plants and chose some lantanas. They're not the dahlias I'd hope to have along the front walk, but they will grow bushy and green and have some nice color while we wait for the mums to bloom in the fall. I made a discovery while pulling out the dahlias, which I'd planned to toss away. You can see in the top photos that there are some tiny dark green leaves along the stems. They seemed to be new growth. In hopes that the yellowing was the result of overwatering sometime during their little pot lives, I've moved them to the back yard. Three of the ten are planted in the space along the fence that has seen two years of tomato failure.  

 The other seven are now in one of the squares that also holds two more hearty dahlias that survived the winter. I know they're too close together, but I'll fertilize them well. If they live, they live. If not, well ...



It's been a month since I last posted. I took some progress photos this morning, but I'm going to put them in a separate post or this one will get way too long. While I'm working on the next post, take a look at the lavender in foreground of the photo above. It survived the winter and is growing heartily. The tiny flowerlets are just beginning to open and are already fragrant and attracting hummingbirds.