- You Will Get 50 Seeds Of Verbena Quartz XP Silver Flower Seeds. - Watering: Medium. - This is 50 Verbena Quartz XP Silver Verbena Quartz XP is one of the best selling variety of Verbena. - These are great to add to hanging baskets and put in 4" pots to resell. - These are early to bloom and keep blooming out and are a very strong plant grow about 12" in height and spread to about 14" these are pretty bushy.