Unfortunately there is not a chemical that we are aware of that would kill the dogfennel and not also kill the blackberry plants. Â You could use a glyphosate based product, but care should be taken to not spray the blackberry plants as they could also be killed.
Unfortunately, Johnson grass and Orchard grass are both perennial grasses. Therefore, we are unaware of any selective herbicide that would kill the Johnson grass and not harm the Orchard grass. In this instance we would recommend spot treating the Johnson grass with a non selective glyphosate herbicide such as Gly Pho-Sel Pro with 41% Glyphosate and reseeding. Please be sure to read the product label for complete use instructions before use.
You could use any Glyphosate product to kill any and all weeds and grasses that might come up through the rocks. You can spray it as often as needed to get the control you need.
Gly Pho-Sel Pro
http://www.domyownpestcontrol.com/gly-phosel-pro-41-with-surfactant-p-1844.html
Gly Pho-Sel Pro 41% with Surfactant is a non-selective herbicide so it should NOT be applied to desired Fescue (will kill the lawn grass). You can spot treat with weeds and reseed those areas if needed. Please refer to the product label for details on rates and full application instructions.
Gly Pho-Sel Pro 41% with Surfactant will kill dallisgrass, and anything else that it touches. Dallisgrass is a weed that is notoriously difficult to eradicate quickly once it is established. A better option woud be Certainty Herbicide or Dismiss NXT Herbicide . Both are labeled to suppress dallisgrass in bermudagrass as directed on the product label. To prevent it coming back you would use a pre-emergent herbicide such as the Dimension 2EW.
Gly Pho-Sel Pro 41% with Surfactant will kill grass, weeds, and ornamentals. It should not be applied to desired lawns, plants, flowers, etc. It does not remain in the soil (contain a residual) after being applied and should be applied directly to the foliage of the weeds you are trying to eliminate. It can take several applications to achieve the desired results and you may notice visible effects on most annual weeds occur within 2 to 4 days. Keep in mind that this is only a post-emergent herbicide; it does not prevent new weeds from germinating.
The best product would likely be a non-selective weed killer such as Gly Pho-Sel Pro. Gly Pho-Sel Pro with 41% Glyphosate is a high quality fast acting systemic total vegetation weed killer. Sprayed on weeds and grasses, Gly Pho-Sel Pro 41% starts working fast, within 1-2 hours, and kills weeds and grasses on contact, roots and all.
Gly Pho-Sel Pro is a non-selective herbicide, which means that it will affect any plant that you spray with it, including grasses and vines at a higher rate. If are treating a lot of brush or direct treatment of stumps then we would recommend using Crossbow Herbicide for those applications. Keep in mind that you can only prevent new growth on freshly cut stumps; no herbicide is a substitute for removal of the stumps.
You could use Gly Pho-Sel Pro 41% with Surfactant to kill any and all weeds and grasses that might come up through the rocks. You can spray it as often as needed to get the control you need.
Gly Pho-Sel Pro 41% with Surfactant can be used to kill any weeds in an area you want to plant edibles. You would need to wait 2 weeks after application to plant in the treated area.
Gly Pho-Sel Pro 41% with Surfactant has a shelf life of 3-5 years from purchase if kept away from extreme temperatures.
Gly Pho-Sel Pro 41% with Surfactant is a non-selective post-emergent herbicide and will kill grasses and weeds that are sprayed. It is not a pre-emergent herbicide. We do offer pre-emergent herbicides here.
Gly Pho-Sel Pro 41% with Surfactant is not labeled for cactus. We would recommend a product like Remedy Ultra Herbicide or Tordon RTU Speacialty Herbicide.
Unfortunately, Bermuda grass is so closely related to St. Augustine grass that there is nothing that will remove Bermuda from St. Augustine and not hurt the St. Augustine as well. In your situation it is recommended to spot treat the Bermuda with a non-selective glyphosate product and kill it directly, then replant St. Augustine in those areas.
