• Blackberries are a delicious treat fresh from the vine.blackberries image by Alison Bowden from Fotolia.com
  
  Blackberries are a type of bramble that grows with or without thorns. These plants are fairly low maintenance and ideal for home gardeners. The thorny variety grows erect and needs minimal support, while the thornless varieties often have a trailing growth pattern and need significant support. These plants require full sun and well-drained soil to thrive. Blackberries grow throughout Pennsylvania.
  
  

Thornless Blackberries

• Thornless blackberries are easier to pick than the thorny variety but are less cold hardy. The thornless varieties should be grown in the south of Pennsylvania where winters are milder. Chester is one of the most common thornless blackberries to grow in Pennsylvania. Although this variety ripens late in the season, according to Pennsylvania State College of Agricultural Sciences, it bears good quality fruit. This blackberry will need support as it has a trailing growth habit. Triple Crown is an erect growing thornless blackberry with large extremely sweet fruit that ripens in mid-summer.
  
  

Thorny Blackberries

• Although blackberry thorns impede access to the fruit, these brambles produce sweet fruit that is hardier than the thornless varieties. Shawnee blackberries bear late in the season. The berries are large and sweet with a good flavor. Shawnee has demonstrated it is resistant to a disease called orange dust that can affect blackberry brambles. Darrow is another thorny blackberry that grows well in Pennsylvania. This plant produces medium-sized fruit early in the season and is one of the most winter hardy of the thorny blackberries, according to Pennsylvania State University.
  
  

Primocane-bearing Blackberries

• Unlike other varieties of blackberry, primocane-bearing blackberries bear fruit on new or current year canes. This eliminates the waiting time before harvest of new plantings as well as allows the possibility of more than one crop a year. These canes can be grown in areas with severe winters as the fruit is produced on canes grown in the current season. Frost damage isn't an issue as the canes are pruned to the ground in fall. Primocane-bearing blackberries are resistant to many diseases that attack traditional, or floricane, blackberries since most diseases attack canes in their second season. This variety of blackberry does have thorns and yields are smaller than other varieties, according to Pennsylvania State University. Prime-Jim, Prime-Jan and Prime-Ark 4.5 are primocane-bearing blackberries that ripen throughout the summer.