In his series on invasive plants, C. Colston Burrell discusses many plants that can take over the landscape. Here he provides two lists of additional plants to be wary of. Remember that plants considered invasive in one area of the country may be safe to grow in other areas. Check with your local extension service for regionally specific lists.
   
Plants Grown As Ornamentals That Are Invasive

Acer platanoides
Ailanthus altissima
Albizzia julibrissin
Arundo donax
Buddleja davidii
Caragana arborescens
Cortaderia selloana/jubata
Cotoneaster species
Euonymus fortunei
Euphorbia cyparissias, dulcis ‘Chameleon’
Fallopia japonica  (Polygonum cuspidatum)
Foeniculum vulgare
Hedera helix
Hibiscus syriacus
Iris pseudacorus
Ligustrum species
Lonicera japonica
Lotus corniculatus
Melilotus species
Lysimachia nummularia
Miscanthus sacchariflorus
Myosotis scorpiodes
Paulownia tomentosa
Pennisetum alopecuroides
Perilla frutescens
Phalaris arundinacea
Pinellia species
Populus alba
Rhodotypos scandens
Rosa multiflora
Salix species
Sapium sebiferum
Sorbus aucuparia
Tamarix species
Ulmus pumila
Viburnum opulus, lantana, sieboldii
Vinca minor
   
Plants to Watch

This list includes species that exhibit those traits shared by a number of invasive species. While they may not be invasive in all regions of the country, they bear careful observation and reporting. For information on evaluating the invasive potential of ornamental plants, Sarah Reichard, University of Washington, has developed guidelines. For a copy of the guidelines, see Reichard, S. 1999. A Method for Evaluating Plant Invasiveness. The Public Garden 14(2):19-21.

Angelica gigas
Aralia cordata, continentalis
Arum italicum
Berberis species
Cardamine pratensis and others
Cestrum parqui
Clerodendrum species
Echium species
Geranium x oxonianum and others
Mahonia species
Persicaria (Polygonum) species
Petasites japonicus
Ribes sanguineum