Ask Mr. Smarty Plants

There are thirteen members of the genus Ilex (holly) in our Native Plant Database, but none of them have the common name "Savannah." That is probably a trade name assigned by a grower to a hybrid of North American natives Ilex cassine (dahoon) and Ilex opaca (American holly). Even though both parents are natives, the "x" indicates a hybrid, and we do not have hybrids in our Native Plant Database.

According to this USDA Forest Service website Ilex x attenuata 'Savannah', the shrub does not have invasive roots, so you are probably not seeing suckers but, as you say, seedlings. From this same website, propagation is by cuttings and grafting. This is because the plant you have is a hybrid, and seedlings would probably not breed true. This doesn't help with your problem, of course, just something to know. If you planted these hollies to attract birds with the berries, you may have done too good a job. It sounds like the birds are taking the berries out into your lawn to eat them, and then dropping seeds on the ground. If your grass is thin, it may be giving the sprouts a chance to come up. Short of pruning before berries appear on the shrub, we don't know of any way to prevent that happening, and the berries may well be one of the reasons you chose that particular plant. You're not going to want to hear this, but pulling the sprouts out before they have a chance to get much root going is about your best bet. We don't know what your lawn is, but it is probably a grass, which would be a monocot. Your holly is a dicot, or broad-leaved plant. If the problem was really getting out of hand, you could try a dicot-specific herbicide, but that's pretty extreme. We recommend neither for nor against pesticides, and hope most people use them only in situations where there is no other practical solution. If you spray a broad spectrum herbicide on the lawn, you will be able to kill the holly seedlings, the grass and any other plants in range, like the other ornamentals in your garden, trees, etc. A dicot-specific herbicide would kill the holly seedlings, but not the seeds waiting to sprout in the ground, and again, you have the problem of spray drift into other parts of your garden.

You need to ask yourself some questions. For instance, why did these berries just start sprouting this year, after the plant had been in place some time? And are you really sure these are holly seedlings you are seeing? Something else may be getting seeded into your lawn by water, wind or wildlife.  Is your lawn healthy, in which case it should be able to suppress the seedlings. Has your holly always produced a lot of berries? The plant has the best berry production in full sun; if you have cut down or trimmed a tree that has been shading that holly, the extra sun may be causing extra berry production. 

Our recommendation is to start by encouraging thicker coverage by your lawn grass, coupled with removing the seedlings as they emerge. Try that for a year or so; if it doesn't work, you will have to decide if you want to go the herbicide route or even cut down and remove the holly, the source of the fruit and seeds.