Blackberry Plants "Prime-Ark Traveler" Price Includes Four (4) Plants The price includes Four (4) "Prime-Ark Traveler" Blackberry Plants with Priority USPS Shipping. These are shipped in 2 1/2 inch pots with at least a 2 inch root system and are 3-6 inches tall. Prime Ark Traveler is the second thornless primocane fruiting blackberry released by the University of Arkansas. A blackberry usually grows one year and doesn't fruit until the following season. I recommend starting your plants off in a 4 inch pot using a good organic potting soil with fertilizer and beneficials already mixed in. See Full Product Description for more information on Variety and How to Grow