Surflan is often used for this type of weed control with great results depending on the type of weeds you are trying to prevent. You will need about 3 fl oz of Surflan per 1,000 sq ft area. Be sure you review the product label to make sure your desirable plants are listed as being tolerant to the product. Surflan products are known to be pretty thick and will likely clog a hose end sprayer so it is best to apply with a pump or backpack sprayer. The other problem with using the hose end sprayer for the Surflan application is that they are not very accurate and you can wind up dispensing more/less product than needed in a given area which can lead to less than desirable results. With pre-emergents it is important to apply the right amount of product over an area and water in so that it gets down to the soil to create the barrier.
Pets should be out of the area during treatment with Surflan Pro until the area dries. Typically a few hours is best. Once dry it is safe for pets to return to the area.
Surflan Pro Herbicide can be applied to well established St. Augustine lawns and it is labeled for sandburs. Please refer to the product label for full mixing and application instructions. This product is a pre-emergent so it will prevent, not kill existing weeds.
Depending on the type of weeds you have in your ground cover and the type of ground cover you have will depend on what product options may work for you. Without more specifics we cannot say for certain that the following products will get rid of what you have and will not harm your ground cover. You will want to check the product labels to ensure they meet your needs.
For post emergent control (killing something that has already come up in your treatment areas) if the weeds are grassy you could use something like Grass Out Max or Fertilome Over the Top. This will only kill and target grasses coming up in ornamental beds. If you have broadleaf weeds, hand pulling or spot treating with roundup for post emergent control is about the only option. Broadleaf weed control products cannot be sprayed over the top of ground covers as they are broadleaf plants and will likely be harmed as well.
For pre emergent control (preventing weeds/grasses from coming up through treatment areas) you have a lot more options to choose from. Surflan Pro/Surflan AS, Gallery 75 DF, Snapshot and many others would be wonderful options that you can use in spring and fall to help prevent persistant weeds from coming back throughout the season.
Again, please check the product labels on each page to ensure that the weeds you are targeting and the ground cover you have are on the label as safe for use.
Be sure to store Surflan Pro in a cool dry area. Ideally, temps would be best above freezing and below 95 degrees.
Surflan Pro Herbicide is a pre emergent herbicide that will prevent weeds and grasses from germinating. If it is applied to a moss lawn, it will prevent new weeds, including new moss, from emerging. It will not hurt moss that has already germinated.
You can use most pre-emergent herbicides that are safe for turfgrass such as St. Augustine around established trees such as oak trees. Surflan Pro is popular for use around ornamental plants and on warm-season turf like St. Augustine. Hi-Yield Weed and Grass Stopper with Dimension is a great choice for a granule for spring application. If you would like to provide us with more information about the weeds you are targeting how much area you are covering, then we can offer other recommendations.
Surflan Pro Herbicide will prevent sandburs but it will not kill any that are currently actively growing. Celsius WG however, will treat Sand Burrs on a post emergent basis to kill any that are currentlygrowing in your lawn.