2 questions: 1. I have two bushes that are prolific with flowers and then red berries. But, the berries never get large and are bitter when they turn black. 2. These large non-fruit producing stems keep popping up. I keep cutting them back. Is this the right thing to do and why do they grow?
It sounds like your plants are getting witches broom. The disease causes those stems and also saps energy away from producing stems, which means inferior, poor tasting fruit. This article will have more information and how to control it:
http://www.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-FR-S-3.pdf
How do you keep Japanese beetles off of blackberry bushes? Is there a pesticide that is safe to use?
Here is an article or two that you may find helpful: https://www.gardeningknowhow.com/plant-problems/pests/insects/japanese-beetles.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/japanese-beetle-resistant-plants.htm
I have several large blackberry bushes that appeared very healthy this spring and fruited well. The canes are now dying, with the leaves and fruit turning brown. The new canes are coming in strong. Any reason for the fruiting canes to be dying back? Thanks!
There are several fungus that can cause this. I would treat the plants with a fungicide now to help protect the canes that are growing in now. The other canes should recover their leaves this year, but they will not fruit again.
First year blackberry canes are 12 feet long with numerous 24 inch branches. It's only early July---what do I do?
First-year canes, also known as primocanes, appear as stems that arch or trail along the ground. They usually bear large compound leaves with five or seven leaflets; they do not produce any flowers or fruit. Second-year canes grow to become what is known as a floricane. The stem will no longer grow taller, but will begin to produce lateral buds and flowers. Also, these normally have smaller leaves with only three or five leaflets. For information on pruning, this article should help: https://www.gardeningknowhow.com/edible/fruits/blackberries/blackberry-pruning.htm
Our blackberry bushes are healthy and thriving and have many berries, but some of the berries have white seed covers and some berries have dry seeds here and there on them. They are coming more and more as the season goes on. Can it be that wasps are draining the juice from the seed covers or do we have a worse problem?
If it is what I think it is, then it is simply seeds that were not properly pollinated. Ths summer has been hard on pollination of plants, due to the high heat and humidity in most of the country. This makes the pollen stick together and pollination is not as successful as it should be. If it is pollination, these white cells are also shriveled and stunted. They are safe to eat though.
Early last year, I planted several thornless blackberry plants. This year there have been a few berries so far, but there are some new vines. The ones I planted mostly have leaflets in groups of three, but the new vines have groups of five leaflets. Other than that they look the same. I'm wondering, are these new vines really the same plant??
Thornless blackberries can have either 3 or 5 leaves in a group so it could be the same plant and likely is. There is an outside chance that you are seeing the plant revert, but until you see some other difference, such as in the fruit or the canes, I would not worry about it.
I live in Wittman, Az in desert conditions. I have just bought some former horse property, all dirt (clay type). There are 2 easements. I want to plant a blackberry hedge on my side so I can limit access to my living area. What should I do to prepare the ground for this planting? Should I provide a support trellis? I believe I have until spring before I plant, so I have time to develop the soil. I plan on eating/canning the fruit. Thanks.
For hedge plantings, I would probably go with erect varieties rather than the trailing types (which would benefit from a trellis), though the choice is yours. They should also be planted about 2-4 feet apart for an ideal hedge. These articles should help as well: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/how-to-improve-clay-soil.htm
https://www.gardeningknowhow.com/edible/fruits/blackberries/growing-blackberry-bushes.htm