Some aquatic plants grow and spread quickly, potentially overcrowding a pond and competing with other plants. While certain species are considered invasive, others simply require regular maintenance to prevent excessive growth.
The following ten pond plants may require additional management. Before adding any aquatic plant, check local regulations, as some species are restricted or prohibited in certain areas.
10 pond plants to monitor
- Canna (Canna spp.): These tropical plants produce colorful flowers and attractive foliage. Some varieties spread through underground rhizomes and may require periodic division.
- Aquatic crinum or swamp lily (Crinum americanum): A moisture-loving plant with long, strap-like leaves and white flowers. Established plants can form large clumps that may require thinning.
- Water snowflake (Nymphoides indica): Produces floating leaves and delicate white flowers. It can spread through plant fragments and new plantlets, potentially covering large areas of the pond.
- Water lettuce (Pistia stratiotes): A floating plant that reproduces rapidly and can form dense mats across the water's surface. It is regulated in some locations.
- Cattail (Typha spp.): Spreads through underground rhizomes and seeds. Cattails can form dense stands that crowd out other aquatic plants. Some cattail species are native, while others are invasive.
- Creeping Jenny (Lysimachia nummularia): A low-growing plant with round green leaves and yellow flowers. It spreads along pond edges and can overtake nearby plants.
- Parrot feather (Myriophyllum aquaticum): A fast-spreading aquatic plant with feathery green foliage. It can form dense growth and spread through plant fragments. This species is invasive and prohibited or regulated in many areas.
- Taro (Colocasia esculenta): A tropical plant with large, heart-shaped leaves. It can spread through underground structures and establish dense colonies in suitable climates.
- Water forget-me-not (Myosotis scorpioides): Produces small blue flowers with yellow centers. It spreads through seeds and creeping growth and may establish itself beyond its original planting area.
- Pickerelweed (Pontederia cordata): A North American native aquatic plant with purple-blue flower spikes. Although beneficial to wildlife, it can spread through rhizomes and form dense colonies that require occasional thinning.
How to control aggressive pond plants
To help prevent aquatic plants from overcrowding your pond:
- Use aquatic planters: Keep suitable rooted plants in containers to help limit root expansion and simplify maintenance.
- Thin plants regularly: Remove excess growth before plants overcrowd the pond.
- Remove unwanted growth completely: Collect loose roots, stems, and plant fragments that could establish new plants.
- Monitor floating plants: Remove excess floating vegetation to maintain open water and allow sunlight to reach submerged plants.
- Dispose of removed plants responsibly: Never release unwanted aquatic plants into natural waterways, storm drains, or nearby wetlands. Follow local disposal requirements.
Important: A plant that grows aggressively is not necessarily classified as invasive. Always verify whether a species is permitted in your state or region before purchasing, planting, or sharing it.
Proper plant selection and regular maintenance help maintain a balanced, attractive pond without allowing individual species to dominate.