Will I damage a well established tree by using vegetation killer in a large bed underneath?

The previous owner of my house made a huge flower bed under a 100 yr old Dogwood. I have screened the area put a combination of mulch and small stone and have tried to plant items such as ferns and hostas. Because the area is so big it is hard to maintain and there are so many weeds and wild flowers they choke out everything. I would like to just leave the rocks and mulch but I'm afraid if I use vegetation killer I will damage the tree.

Will I damage a well established tree by using vegetation killer in a large bed underneath?
It all depends on the type of chemical and how it kills the vegetation. If you use a chemical that is spread on the ground and "watered" in so that it is absorbed by the plant roots, then you will surely damage the tree. On the other hand if you use a chemical that is sprayed onto the offending plants so that it is absorbed throught the leaves, then the risks are minimal at worst. Just be careful not to apply it on a windy day and avoid any spray contacting the tree. Check your local nursery for a specific vegetation killer that will suit your purpose. There are some that kill Everything they come in contact with, others target specific plants.
Reply:pull the flowers and use a weed killer. it's best to avoid putting total vegatation killer under the dripline of the tree.
Reply:make sure what you use is not active in soil or water, then it will only kill what you spray it on, and not travel thru the soil with rain or run off and kill roots, that will kill your tree. in our area (iowa) we use a weed killer called round-up, there are versions by different names and companies. once it hits the soil or gets in water it is no longer effective, so it is safe to use under trees or in flower beds as long as you dont spray it on foliage or bark or any part of the plant you do not want to kill. good luck
Reply:The problem with using any weed killers, including natural weed killers (vinegar) near the dogwood you would risk the chance of it leaching into the soil and harming the tree (I am assuming that your dogwood is the flowering pink/white kind).





Instead what you can do is to create a healthy bed for garden by proper fertilizing twice a year. And make sure there is adequate drainage in the flower bed. And don't water your garden plants during the evening hours. At around the break of day (dawn) is a better time to water them; between the hours of six am to eight am. To kill the weeds without harming the tree you could lay down tarps such as Weed Control Fabric, Landscaping Fabric, Landscape MAX Weed Defense Fabric and securing them down with Landscape Anchor Pins. If you cannot get those right away you can use regular tarp or dark plastic sheet over the weeds and hold them down with rocks. If you use that don't put it to close to your plants; they need to be able to get air in the soil.


Some people use sheets of wood over the areas; however if there are snakes in and around your place you risk the chance of one of them hiding under the wood. And if you have not already done so; you need to add mulch around your plants to keep the weeds out. If you use just dark plastic sheeting (non-breathable kind) after a few days check to see if the weeds are gone. Once they have remove the tarp and then you can apply the mulch to those areas too to prevent any more weeds from returning.
Reply:If you use a low potency weed killer and be careful to only spray the weeds not the tree, you should be OK. Most products that homeowners can buy are only harmful when they touch the surface of the plant. Ask at your local garden centre of hardware store and they will point you in the right direction. It sounds like a lovely tree you are caring for.