Question
Earlier this spring I planted a container with Fireball Coleus, Lemon Licorice (helichrysum petiolare) and a Verbena hybrid (Lanai Burgundy). The growing medium is a soilless potting mix. At planting time I pinched back all three for a fuller pot.  The coleus and lemon licorice is doing fine but the Verbena has yet to bloom.  I water the pot every day and fertilize once every two weeks with a very diluted solution of 10-54-10 fertilizer.  Why won't the Verbena bloom?  It's had flower buds for a few weeks but none have opened.  What should I do?  Thank you for your help.

Answer
Janet,
Is the container in at least 5 hours of dead-on sun including the noon hour?  This is what verbena needs to bloom well - coleus and licorice plant will do fine in part-shade, but the verbena needs a ton of sun in order to bloom.

Check too to see if the verbena might have mildew - the downside of planting it with other plants is that sometimes they shade the verbena and because the planting is tight there isn't good air circulation around the plants. And because containers dry out daily and we water them daily the air around the pot stays moist and sometimes the leaves get wet and all of the above can lead to mildew.  The leaves would look as if they have a powdery coating of light grey on them.  Mildew can weaken a plant so that it doesn't bloom.

And lastly, current research shows that annuals - especially the new hybrids - bloom better with a slightly higher level of NITROGEN!  Many fertilizers have changed their formulation to suit this finding - so if you use Osmocote Indoor Outdoor time release, for example, you'll see that the first number is higher than the middle.  So I think that at the very least you should find a fertilizer with either even numbers across the board or a higher rate of nitrogen as opposed to the high phosphorous level you're using now.

I hope this helps!
C.L.