They sprawl outward first year next year new growth be straight up I would tie what there more upright something like tomato cage work this first year. Your plant looks like a Arapaho if is it be erect once get going. Blackberries are heavy feeder mean take often fertilizing once a month until next year. Don't fertilize when fruit on bush it run taste berries. If grows 7 foot tall by November stop fertilizer until good blossom forum next year fertilize then and after fruit harvest. You need grow long canes because low chill hours in Tampa Florida. That plant will take over your raised bed later years.

If Gator is right that it is Arapaho they need like 400 chill hours......I don't think you get close to that amount. I am 60 miles north of you and just get 400.

Gator Rider and Bamboo Rabbit,
Thank you so much for your responses! I must say, Gator, when you mentioned 7 feet, I gulped hard. :-)
Bamboo, as I said, I am a complete novice and am unfamiliar with chill hours. What does that mean? Sorry if that is the dumbest question ever.
I looked through my garden stuff and found the tag for the blackberry bush and it is called "Natchez". Know anything about those??

Karen

Natchez is a super grower, Yeah 7 foot vines that are mostly erect. They do need some support, and such. Google "how to care for natchez blackberries" for info.
Many better tasting BB are out there, but Natchez is OK, not bad. One thing about Natchez I really like is it is easy to grow. I have about 8 different blackberry cultivars and Natchez outgrows them all. You probably will never be able to get rid of it. It will start to grow upright eventually.
OK, Natchez requires 500 chill hours, you probably will not get fruit. You get around 200-300. Anybody know what cultivars will grow with this amount? I know Kiowa and
Ouachita are in that range any better ones??

A chill hour is when the temperature is between 32 and 45 degrees, for an hour. Somewhat hard to come by in Florida. The hundreds of hours required for some caneberries is so they will fruit better the next year.

Blackberries and raspberries grow on canes, not bushes.

Has anyone ever tried grafting of blackberries onto raspberries?

Also for anyone interested, I have a number of small raspberry plants that I would trade for thornless blackberry.

"Has anyone ever tried grafting of blackberries onto raspberries? "

Probably not since the graft would be good for 2 years at most.

So, it sounds like I got scammed as blackberries really do not grow well here. I don't want to kill the plants, but it seems that if they are not going to be producing fruit very well, then maybe I should move them to an area of my yard that is not in my main garden space. Can I move them without killing them?

Thank you for all of your responses.

P.S. I guess that the garden center didn't really care about whether I got fruit or not, just selling the plant. :-(

Natchez 400 to 500 link help locate your chil hour averages.
Natchez the newest blackberry plant out there, but there newer one coming out. Natchez would be one best choices from Arkansas to try in your area you get berries but bumber crop may not happen. One thing you can do is remove all leaves around christmas and shade plant dark as can without heating up cover all but north side plant double cover with air space is best. In Mexico they get 2 crops year by removing leaves they do this by not having any chil hours chil hours are number hours 45 degrees and below this give plant a rest period.
A black berry plant grow 4 inches per day once established fertilized and watered along with sunlight heat at night may get more 4 inches per day time 30 days 120 inches divided by 12 inch equals 10 foot in one month.

Here is a link that might be useful: Chil hour map

'I got scammed as blackberries really do not grow well here'

Yes it is common to happen. A regional buyer probably bought them, and maybe in the pan handle they will grow.
But you most certainly can grow blackberries!!
I would try this one. Look at the size of that berry! You may be able to find a local source? Anybody know where to get these in FL? You could always purchase online.
Google Rolling River Nursery they have them for 8 bucks!

Here is a link that might be useful: Tupi blackberry

My gosh, Drew51, that is a huge blackberry! My mouth was watering! I will look into getting some and giving them a try here. Maybe the only thing I have going for me in the chill hours department is that Valrico is typically 10-12 degrees cooler than Tampa when it gets cold. That might provide a few extra hours. We'll see.

Thank you again, everyone for the great information!

Karen

Can you dig it up, put it back in the pot, and bring it back to the garden center, tell them it was not suited to climate and they shouldn't be selling that variety? They might take it back.

Apache is also #1. I can't believe it, their as big as golf balls and super sweet, but UV sensitive w/white spots.

Apache is also #1. I can't believe it, their as big as golf balls and super sweet, but UV sensitive w/white spots.