All bare ground/vegetation management products like Total Vegetation Control TVC , are recommended to be applied outside the dripline of desirable trees and plants to prevent their feeding roots from absorbing the product. Inside the dripline is where these roots are closest to the soil and could absorb any such product so we would not recommend using any in the area you have described. The best thing we could recommend is using a glyphosate based product like GlyPhosel Pro to spot treat the weeds you want to kill around the tree and then use a pre-emergent such as Surflan Pro or other that is listed for the weeds you need to control.
TVC is not labeled for coffee senna, so we cannot say for sure that it would work. Unfortunately, we are not aware of a product we carry that is labeled for coffee senna. You may want to contact your local cooperative extension office to see if they can recommend something that has worked for others in your area. This article also has some information which may be helpful.
You could potentially use a hose-end sprayer when applying TVC, however, you need to be very careful that you are not overspraying onto or near any desirable plants or roots. For most applications, you would use just under 1 ounce of the TVC per 1000 sq ft in no less than 2 gallons of water, plus a Non-Ionic Surfactant that you apply at 0.25% to 1% of the total spray volume (0.25% v/v is equivalent to 1 quart in 100 gallons) in accordance with the surfactant labeling. Also, be sure that you clean your sprayer thoroughly after use if you plan to use it with any other products.
TVC Total Vegetation Control would be a good product to use under the pool to prevent growth of most grasses for up to 1 year. Applying a fabric liner under can also help. If they are coming through the liner that could mean a hole was already there that allowed them to growth through depending on the weed, very few can grow through the liner itself without a hole/acess to sunlight. If the grass has already grown, pulling and patching is best.
TVC Total Vegetation Control is toxic to fish and other aquatic life. It must be applied at least 25 feet away from a lake in order to prevent any runoff.
Per the label, that applications of TVC Total Vegetation Control directly to the soil beneath desirable trees can result in root uptake and cause injury or death to desirable trees. To prepare a dilute solution, mix 8 to 12 fluid ounces of TVC with one gallon of water.
TVC Total Vegetation Control should have its own sprayer as it will kill most vegetation so if you are using a selective product and the tank, wand or nozzle was not cleaned/rinsed completely some produc could harm those unintended areas.
TVC Total Vegetation Control will work great to treat around the fence rows.
You would use roughly just under 1 ounce per 1000 sq/ft in no less than 2 gallons of water. So you would need about 4 ounces in at least 8 gallons of water to cover your 4000 sq. ft.
TVC Total Vegetation Control is not specifically labeled for English Ivy but could injure the species if treated with the product.
The best way to treat under the landscape would be to remove the rocks and treat the ground below it before replacing the rocks so that you can be sure the herbicide actually reaches the ground below it. If you are able to do this, and there are no desirable plants in the area, then you could use a product such as Martins TVC, which will prevent new plant growth for up to a year when used on the bare ground itself. (You would not want to try to spray this product directly on the rocks because of its blue color.)
If you only get occasional weeds popping up, then it would be easiest just to spot spray as needed with a non-selective post-emergent such as RoundUp QuikPro.
You may have luck using a granule pre-emergent which is then watered into the ground, but it would be very important to use a high enough volume of water to carry the active ingredient down into the ground. If the rock layer is thick, then this would not be effective. Keep in mind that many pre-emergent herbicides have a dye in them that could stain the rocks, as well. If you would like to tell us more about what specific weeds you are targeting and how much area you need to treat, then we would be happy to make a more specific recommendation for you.
