Plant of the Month-July 09

From In the Garden

I have chosen the dahlia as July's Plant of the Month in my garden. Close (very close) runners up were: coneflowers, daylilies, phlox, and veronica. Dahlias are the star of this garden and who can miss the large colorful (some would say blowsy) flowers?

I grow three cultivars, a red one called 'Garden Wonder', and two purple ones; a light purple one called 'Lavender Perfection' and a dark purple one called 'Thomas Edison'. All three are dinner plate dahlias. I find the dinner plate dahlias are the easiest type of dahlias to grow.

I grow my dahlias in large pots that sit in front of my garage on concrete. This is the ideal spot in my garden because dahlias are one of those plants that really must have full sun in order to do well. The driveway here at Tiger Gardens gets about 6 hours if I am lucky, but it is the most sun anywhere here so it has to work. The pots work well because dahlias are not hardy here in my Zone 6/7 garden. I've grown dahlias for more than 5 years now and have dug the tubers each year, but this year I'll just move the pots to the garage as winter comes on. One year I was lazy and forgot to move the tubers to a protected place (though I had dug them) and lost them due to the freeze/thaw cycles that rotted the tubers. I was pretty upset because those ones were yellow and I had grown them the longest. Oh well.

Given the right conditions dahlias will bloom non-stop from June to October here in my garden. In addition to full sun, dahlias need plenty of fertilizer to bloom reliably for a long time. I add Osmocote slow release fertilizer and mulch with compost at the time of planting. I also add a cage or stake as well in order to hold up the top heavy plants. Dahlias can get mighty heavy and will fall over if not supported. Deadheading is required in order to keep the plants tidy and to encourage new blooms. I have to water my pots normally every day or every other day. In years past when the dahlias were planted in the ground, they needed no special watering. Pots are a whole other matter though, and while I knew I'd have to water often I am not happy about it. I am experimenting with milk jugs (hidden among the foliage) filled with water and with a few pin holes poked in the bottom of the jug so the water can trickle out slowly. So far the issue has been to get the water flow correct so that the water is delivered at just the right rate. It's been a slow process getting the 'passive watering system' precisely tuned.

Despite digging annually and having to regularly water the dahlias, dahlias are truly a July garden star and worthy of the title of Plant of the Month in my garden.

What is your July Plant of the Month?