Wonderful Water Plants

by Kerri Bailey

Water or aquatic plants are essential features for any pond or water garden. They add beauty and color softening the rocks, while providing shelter for fish. The bonus is that they also help keep your water clear and fish healthy. Water plants also compete with algae for nutrients and consume excess fish waste.  So you may want to add more plants to your pond to increase your filtration and pond appeal.

What are Water Plants?

So, what are water plants? They range from plants that tolerate wet feet and areas to plants that can be completely submerged in water. These plants can survive and thrive in wet areas year round (or naturally for their life cycle). Many common garden plants can be used in ponds or bogs that grown along the edges (margins) and stream areas. When plants are grown in water, they produce a different type of roots than soil grown plants. Aquatic roots are long and filamentous with feathery looking root hairs. These roots grow into the water for searching for nutrients, oxygen and are used to anchor themselves. Some plants float on the waters surface that have air bladders inside their leaves or stems to keep them buoyant with roots that grow completely submerged.

Water Plant Groups

Water plants are classified into four main groups: “Water Lilies and Lily-Like”, Marginals, Floaters and Submerged plants. Each plant group is dependent upon where they grow in the pond or how deep they can be submerged in water.

Hardy Water Lily

Water Lilies are the jewels of the pond.  The root or rhizome   grows in deep water (1′-4′) with stems that grow upward toward the water surface.  Leaves and flowers float on the water surface or slightly above.  Water lilies are divided into two types- Hardy and Tropical.  Hardy Water Lilies are hardy from zones 3-9 and can be grown just about anywhere in the country year round. They typically are day bloomers that are available in many colors with leaves and flowers that float on the waters surface.  Tropical Water Lilies need warmer

Tropical Water Lily

temperatures (above 65ºF) and are usually treated as annuals or winterized inside.  They come in vibrant bloom colors with leaves and flowers that stand out above the waters surface. They are either day or night blooming. Check your zone at: http://planthardiness.ars.usda.gov/

Lily-Like Aquatics  Grow similarly to hardy water lilies but have smaller leaves and flowers, and grow in shallower water depths.  They are very versatile working well in containers and in small ponds.  The lily-likes vary in leaf size and shape, temperature hardiness and flower form.

Marginals

Marginal Plants  A very large group of plants that grow on the margins of ponds, bogs or stream edges.  They are grouped as hardy or tropical- hardy plants survive below zone 9  and tropicals survive above zone 9.  Iris & Cattails are hardy marginals and Taro & Papyrus are tropical marginals. Some marginals can survive in wet soil to a few inches of water depth, and others can grow deeper (up to a foot of water).

Floating Plants or Floaters  Plants that float on the waters surface with their roots submerged into the water.  Their leaves have air bladders that keep them buoyant.  Most are annuals ( Water Hyacinths, Water Lettuce) some are hardy (Azolla, Frogbit)

Submerged Plants  What most people think of as “water weeds”.  They are often referred to as “oxygenators” which is misleading, as all water plants consume and produce oxygen. These plants are found under the water surface either freely floating or anchoring themselves to the  bottom.  At times they may grow at the waters surface or out of the water.  Most have insignificant flowers, others have delicate blooms.  Many are considered “noxious weeds” so check the list to see what you can grow in your state http://plants.usda.gov/java/noxious?rptType=Federal

Hornwort

WA State see:  http://www.nwcb.wa.gov/ab_weedlaw.htm

Learn more about water plants at The Pond Pad located inside Alpine Nursery in Puyallup, WA or email at:  thepondpad@gmail.com

Kerri Bailey, owner of The Pond Pad, has been working with aquatic plants and herbs since 1989 and has been in the pond and horticulture industry since 1998.  She has a BS in Biology and is a Certified Herbalist.

 

 

Hardy Water Lily Care

Colorado Peach

Hardy Water Lilies are perennials that come back each spring year after year and go dormant in late fall.  They can live for several years up to 20 years or more, provided they are properly cared for.

Placement:  Full sun, up to 6 hours of sun a day for abundant blooms, although there are a few varieties that can take less sun (Burgundy & Dark Red colored varieties can fade in too much sun).  Water lilies do best in moving water that is oxygenated by a pump, stagnant water may cause them to rot out.  Avoid water splashing on the leaves, and heavy wind & wave action that causes leaves to pull away from stems.

Water Depth: Water lilies are submerged plants- the roots need to be in the water with the

Joey Tomocik

leaves floating on the top of the water.  The roots or pot should be submerged at least in a foot of water up to 2.5′ / 3′. Dwarf varieties can be in less water, the larger ones should be grown in deeper water.  In natural ponds that have stiller water, water lilies can grow in up to 6′ water depth.  If lilies are planted too deep, the stems can break away from the rhizome (tuber).

Fertilizing: Fertilize your water lilies around April or May, monthly until August/September. Do not fertilize your plants when they are dormant and follow the directions on the package.  Use only aquatic fertilizer tablets- not fertilizer meant for soil plants- you can get algae blooms and possibly kill your fish.  You don’t have to fertilize them if you have a heavy fish load, the fish waste turns into nutrients for the plants to absorb.  If your lilies aren’t blooming, they may need to be divided, re-potted or need fertilizer.

Pink Fire Opal

Dividing: Divide mature plants when overcrowded, or have out grown their pot.  In warmer areas, divide your lilies more often, cooler areas divide less often (shorter growing seasons) or every 3-4 years in late spring.  If you clean out your pond, that would be a great time to deal with your aquatic plants-dividing, fertilizing, cutting back foliage, etc. Water Lilies planted directly into the pond may need to be divided every 2-3 years as they will grow faster than they will potted.  A divided water lily needs at least 6 weeks of good growing weather in order to survive winter.  Use a sharp, clean knife and cut 4″-5″ of rhizome on medium to large types and 2″-3″ pieces on smaller types.  Make sure there is at least 1-2 side eyes per division.

Planting:Plant your water lily directly into the pond, or submerge a potted lily in 1′-3′ of

Water Lily Tuber

water depth.  Do not use a planting mix, potting soil or compost intended for soil plants.  These mixes use a lot of oxygen as they break down and can cause your tuber to rot or cause algae blooms.  Use an inert medium- top soil, sandy loam, gravel or an aquatic plant “soil”.   See my blog on Planting Hardy Water Lilies for more details.

Pest Control:  Water lilies get few pests & diseases.  Aphids can be a problem and can spread quickly.  Never use a pesticide on any pond plant that is not labeled safe for aquatic life- fish are very sensitive!  A natural method is to coat the leaves of the lily infected with aphids with “Diatomaceous Earth”or DE- a whitish powder make up the shells of microscopic organisms called diatoms (avoid breathing in the dust particles).

Texas Dawn

The sharp edges of the diatoms cut the insects and suffocate them.  Wait a day and spray off your lily pads with a gentle stream from a garden hose.  You may have to repeat this several times until they are gone.  The fish may eat some of the aphids for you and the DE will not harm fish.  Another potential problem is root rot, which usually happens to potted lilies.

Dead Heading / Leaf Care: Each water lily bloom lasts up to 5 days or so, opening and closing each day until it expires. You can cut spent flowers to stimulate more blooms and to keep your lilies tidy.   Dead or ugly leaves can be trimmed as needed.  Do not cut the “indicator” leaves that grow out from the base of the tuber, they tell the plant when to grow in the spring.

If you have any questions email at: thepondpad@gmail.com or stop by The Pond Pad at Alpine Nursery.  Kerri Bailey, owner,  has been working with aquatic plants since 1989 and in the horticulture & pond industry since 1998.  She has  a BS in Biology and is a Certified Herbalist.  See her other blogs on Planting Hardy Lilies and  Water Lily Facts.