Floating plants move with wind and current. In a pond with a skimmer, that can carry them toward the intake along with leaves and other surface debris. Rather than blocking the skimmer, make a plan for where the plants can stay, how you will collect strays, and whether the species is suitable for your pond and area.
Watch how water moves first
Observe the pond with its normal pump setting and during a breezy period. Note where plants drift and whether they collect at the skimmer opening. A placement that works on a still day may fail when wind changes. Keep access to the basket and weir door clear, and never reduce the skimmer's flow to hold plants in place.
Choose a safe containment approach
A floating boundary or a planted area may help keep suitable species in a designated part of the pond, but it must fit the feature and be secured so it cannot enter the pump. Check that fish and wildlife cannot become trapped or entangled and that the barrier does not obstruct water movement. Avoid improvised loose fishing line in a pond with animals. Ask the feature or containment-product manufacturer about compatibility when in doubt.
Remove strays and excess growth
Lift plants from the basket before they restrict water flow. If a species multiplies quickly, thin it as needed and collect small fragments that could drift back to the intake. Follow local rules for disposing of plants that can spread beyond your pond; never release them into natural waterways. See Pond Plants That Can Spread: What to Check Before Planting for selection cautions.
Keep the whole pond working
After changing plant placement, check that the skimmer still draws surface debris and the pump runs with adequate water. If the skimmer has been repeatedly clogged, clean it according to its manual rather than trying to force plant material through. For the benefits and limits of floating plants, read What Do Floating Plants Do for a Pond?. If fish also enter the skimmer, see How to Keep Pond Fish Out of a Skimmer.