Delaware Just Added More Popular Landscaping Plants to Its Invasive List. Here’s What Homeowners Should Know
Delaware’s invasive-plant rules have a practical new wrinkle for homeowners, landscape designers and anyone planning a garden refresh: four familiar ornamentals have been added to the state’s list, with future enforcement dates already on the calendar.
The Delaware Department of Agriculture updated its invasive-plant information in May 2026. Chinese fountaingrass and Chinese silvergrass are scheduled for enforcement beginning May 1, 2028. Linden viburnum and mimosa, also called silktree, are scheduled for enforcement beginning May 1, 2029.
These are not obscure plants that exist only in wild areas. Ornamental grasses, flowering trees and viburnums are familiar parts of residential landscapes. A homeowner may have seen them around a pool, at the edge of a patio, in a foundation bed or along a property line. That familiarity is exactly why the update deserves attention now rather than at the last minute.
Why Delaware maintains an invasive-plant list
An invasive plant is more than a plant that grows quickly or requires pruning. Delaware defines invasive plants as nonnative plants that can spread and establish widely, outcompete other species, reproduce aggressively or become established in natural areas.
The issue is not simply appearance. When a plant escapes cultivated landscapes, it can alter woodland edges, stream corridors, meadows and other habitats. Over time, aggressive species can crowd out the plant diversity that supports insects, birds and other wildlife.
That is why Delaware’s law prohibits importing, exporting, buying, selling, transporting, distributing or propagating viable portions of plants once enforcement is in effect. The state’s current enforcement list already includes familiar landscape plants such as Callery or Bradford pear, English ivy, Japanese pachysandra, lesser periwinkle, Japanese barberry, Norway maple and winged euonymus. Creeping Jenny, by contrast, currently appears on the state’s plant watch list rather than its enforcement list.
What the new enforcement dates mean for homeowners
For most homeowners, this is primarily a planning issue. If you are considering a new landscape, replacing a screen, improving a patio border or renovating an older planting bed, it makes sense to select plants that will remain appropriate for Delaware well into the future.
The update is not a reason to panic or start removing healthy plants without a plan. Plant identification matters. “Ornamental grass,” “fountain grass” and “viburnum” are broad common names, and one variety may not be the same as another. The Department of Agriculture also lists specific conditional cultivar exemptions for Chinese fountaingrass and Chinese silvergrass.
Before purchasing, moving or removing a plant, confirm its botanical name and cultivar with a qualified nursery or landscape professional. If a plant is already established on your property, do not propagate it or move viable material around the landscape. Instead, make a measured plan for replacement, disposal and replanting.
A replacement should solve the design problem
The best way to approach an invasive-plant replacement is to ask what job the original plant was doing. Was it creating privacy? Offering a burst of spring flowers? Providing a focal point from the kitchen window? Adding soft movement next to stonework? Holding a slope? Giving the garden winter structure?
That question matters because a suitable replacement is not always a one-for-one plant swap. A small flowering tree may be the right solution where a Callery pear once stood. A layered combination of shrubs and grasses may offer more useful screening than a single overgrown specimen. A long border next to a terrace may benefit from massed perennials and carefully selected grasses rather than a row of identical plants.
For Callery or Bradford pear alternatives, University of Delaware resources direct homeowners toward options such as serviceberry, fringetree and flowering dogwood. Each has a different mature size, flowering season, form and site preference. A serviceberry may offer multi-season interest. A flowering dogwood may be especially suited to a different light condition. The right choice depends on the site and the desired effect.
Good design protects the investment
Removing a plant is only the first step. A successful replacement should account for mature size, light, soil, drainage, views, architecture and maintenance. A shrub that fits beautifully when it is installed can create years of unnecessary pruning if its mature size was not considered. A tree can look isolated if it is not connected to the surrounding planting design. A grass can become a maintenance headache if it is placed where it flops into a path.
At Irwin Landscaping, a thoughtful plan begins with the site: sun, soil, drainage, architecture and how the space will be used. That approach makes it possible to replace a problematic plant with one that looks intentional, performs well and supports the overall landscape for the long term.
The larger opportunity is to create a better landscape than the one that existed before. With careful plant selection, a replacement can improve seasonal interest, reduce future maintenance, support local ecology and make an outdoor space feel more complete.
Planning a renovation or new landscape? Talk with Irwin Landscaping about a plant palette designed for your property and Delaware’s changing landscape guidance.
