weed killer without harming plants
I have planted pachysandra plants and ivy plants to cover a hill in my yard. since planting, the hill has filled in with weeds. can i use a spray on weed killer to get rid on the weeds without harming the plants?
There is no herbicide that will selectively kill weeds growing in pachysandra and ivy. Weed killers fall into large general categories--grass, broad-leaved, and total vegetation killers. You would need to use a broad-leaved weed killer, and both your plants have broad leaves.
We'd recommend that you weed by hand and then mulch the bare areas. Any bare soil will always produce weeds. Mulch should not touch your groundcover plants, and be no more than 3-4" deep.
English ivy is a very problematic foreign invasive plant in Maryland (and much of the U.S.) It should never be planted near a natural areas where it smothers native plants that wildlife needs. When it goes up trees or vertical surfaces, it matures and produces berries which birds spread to parks and natural areas. We recommend that you remove it now, before it takes off. It is so aggressive that it is a nuisance to control in landscapes, even in the best of circumstances. Here's more about it: https://extension.umd.edu/hgic/english-ivy