Blue or purple flowering plants are a nice addition to any garden, and one of the best summer flowering tender perennials is the showy Verbena, 'Homestead Purple'. Its low spreading growth habit and long prolific flowering season make it a 'must' in my summer garden. It makes a terrific summer ground cover at the base of taller summer annuals and perennials.
In my garden we have used it as a border plant in an evergreen planting; as a group planting in a flower bed and as a ground cover at the base of white flowering 'Shasta daisies'. In each case the purple flowers create a 'riot of color'. The purple flowers seem to be especially effective when planted with white, yellow or pink flowering annuals and perennials. Dark green leaves make a nice background for the showy summer flowers.
We have had verbena 'Homestead Purple' in our garden for the past five years. Over that period of time it has died back severely twice, due to sudden cold-spells. So although it is considered a tender perennial, I would grow it has a hardy annual here in the northwest. It has been my experience, if the plant has a bit of protections from cold winds and morning sun after a heavy freeze, it will survive. Covering with a cloth material like burlap also helps, but remove the covering as soon as the weather moderates.
It flowers best when planted in full sun. However, we have grown it in part sun and shade, with excellent results. I tried it in a mixed hanging basket, but because of its robust growth habit it seemed to take over the entire basket.
SOIL PREPARATION FOR PLANTING
No special soil requirements are needed. However, the plants will grow and flower best when some organic humus is added to the existing soil. I like to recommend that you add compost (if available), peat moss or processed manure, mixing it thoroughly with the existing planting soil.
New greenhouse grown plants should not be planted until after all danger of frost has passed. Set the plants so the top of the root ball is level with the soil surface. Avoid mulching the plants with bark, sawdust or peat moss. After planting, water-in thoroughly and be sure the plants do not settle deeper into the planting soil.
If you are growing them is group plantings or as a summer ground cover space the plants about two to three feet apart for best show. (the over-all spread of this plant in my garden is usually about 3 feet.)
Since these are fast growing, prolific flowering plants they will benefit from monthly feeding during the summer growing season. Use an all-purpose liquid plant food, applying it at the amount recommended on the label. Apply the fertilizer during the morning hours. On a hot day, the fertilizer should be spread on the soil around the plant. On a cool day, it can be applied as a foliar feed.
PRUNING & PINCHING
Verbena 'Homestead Purple' generally has a rather compact bushy growth habit. However, if the plant tends to get a little spindly, do not hesitate to pinch-back any leggy growth to encourage bushiness. My experience is that this plant does not like to be severely pruned especially plants that have survived the winter. Lightly shear or pinch those plants to stimulate side branching and a bushier growth habit.
As the plants grow they will continue to flower on the new tip growth, so the dead flowers do not need to be removed. Should the dead flowers become unsightly for any reason, simply pinch-them-off.
When possible keep sprinkler water off the foliage, particularity in the late afternoon or early evening. Mildew can become a problem if the plants are kept too wet, or are situated in a spot with poor air circulation.
'Homestead Purple' combines well with the yellow and oranges of the mid-sized, double flowering African marigolds. Dwarf Shasta daises or white Marguerite daisies make nice companion plants. Pink Snapdragons , Stock or Zinnias are also attractive in mixed plantings. In one of my plantings I used a grouping of white petunias on one side, the 'Homestead Purple' in the middle, then French Marigolds in a group on the other side. This combination created a riot of color all summer long.
So if you are looking for a bright spot of purple flowers in your summer garden, consider the showy Verbena, 'Homestead Purple'.