Our blackberries are pretty well done producing for the year.
They were ripe starting around May 24th and continued producing until approximately June 21st. I am still getting a blackberry here and there by July 4th, but only sporadically.
If you want fruit in your Dallas yard and you want it easy, go with thornless blackberries. These have been great for us and prolific producers in only their second year.
These really seem to be hardy plants with few needs. They are erect growing and do not need trellises or staking.
I planted three varieties to extend the season and had berries over a four week ripening period. We planted Navaho, Arapaho, and Ouachita. All are thornless and were developed at the University of Arkansas, so they are perfect for Dallas' hot weather. Needless to say, thornless is the way to go because -- no thorns. Also, these plants don't seem to sucker and can be kept in check. In their second year, the plants generated massive, one inch thick canes. These will grow to seven feet tall, but I am pruning them at about three or four feet to encourage side branching and to keep it tidy. These new canes should produce next year's fruit. Now that the plants are done fruiting, I will probably prune the smaller canes from last year that produced fruit this year -- as I understand it, they will no longer produce fruit.
If you are only going to plant one type of blackberry, I would plant the Ouachita. It has huge berries that make it easier to determine when they are ripe. (I planted the Navahos this year, so I cannot report yet whether they will be superior to Ouachita; however, I cannot speak highly enough about the Ouachitas).
Here is some information on these three types of blackberries from the University of Arkansas:
Arapaho: Earliest of these 3 varieties to ripen with a reported four week ripening period -- approximately the last week in May in Dallas. Fruit size at 5 grams with flavor rate as "good, higher than most thorny varieties," percent sugar averages 9.6 %; moderate yields, usually lower than Apache and Navaho.
Ouachita: Starts ripening about a week to a week and a half after Arapaho -- so about the first or second week of June. Reported five week ripening period, but I would expect less. Fruit size at 6 to 6.5 grams with flavor rate as "very good", percent sugar averages 10-11%; consistently high yields in research trials - "comparable to exceeding Apache and Navaho and consistently exceeds Arapaho."
Navajo: It is reported to ripen two weeks after Arapaho -- approximately the second week of June; however, my experience this year was that it ripened at the same time as Arapaho. It is reported to have a ripening period of five to six weeks, but we'll see. Fruit size at 5 grams with flavor rate as "excellent" and "consistently rated the highest of the Arkansas varieties"; percent sugar averages 11.4%. Moderate yields in research trials - "comparable to exceeding Apache and Navaho and consistently exceeds Arapaho."
You can obtain five gallon containers of these plants from Bob Wells Nursery in Lindale, Texas. Alternatively, next spring, you might be able to find some of these varieties at North Haven Gardens, Lowe's, and Home Depot. Do not buy a variety that you have not researched. You need to stick with the University of Arkansas thornless, erect varieties, or your yard will be overtaken by native blackberries with thorns!!!!
Here are a couple of photos of our blackberry bushes in the yard. We have two beds planted each with two rows of blackberry bushes. In the one bed, there are pear trees planted within the blackberries. In the other bed, we have apple trees planted within the blackberries.
In the following two pictures, we have a row of strawberries in front followed by a row of Nanking cherry bushes. Behind those are two rows of blackberry bushes. The first row are the Navaho bushes that I planted this year and still have small bamboo poles for support. The back row are the Ouachitas and Arapahos that I planted in 2009.