Divide and Conquer: The unique romance of plant propagation

Dividing plants is easy and doesn't require special tools. A serrated bread knife works great for small and medium specimens.
Dividing plants is easy and doesn’t require special tools. A serrated bread knife works great for small and medium specimens.

Birds do it … bees do it … koi definitely do it … and so do plants. In fact, aquatic plants reproduce very freely, although much more discreetly than koi. The big difference with aquatics is that they use multiple reproduction methods … and sometimes the same plant uses several at once!

Nature’s bountiful procreation strategy provides obvious opportunities for growers. However, it can also be profitable for other water garden and pond businesses. Because aquatics have never-ending reproduction cycles, there is an ongoing need both for midwives to help with the process and for using the added plants. This basic introduction to aquatic plant propagation will help you determine ways to expand your services and meet this ongoing need.

There are many kinds of aquatic plants. The majority can be propagated by root division, which quickly results in mature plants.
There are many kinds of aquatic plants. The majority can be propagated by root division, which quickly results in mature plants.

Down and Dirty: The Basic, Most Popular Method

Water gardeners often use division, which is the simplest and most common technique for propagating plants. It also happens to be the easiest, quickest and most reliable way to get more full-sized plants just like the parent. Division is not difficult, although it’s messy and definitely gets dirt under your fingernails. (Neat folks use rubber gloves … extra long are best.) Of course, if your koi have spawned, you already know the meaning of messy.

There are numerous factors that influence how long to wait before a plant will need dividing: length of growing season, plant variety, container size, soil, fertilizing schedule, amount of sun and pest damage. Besides making more plants, there is another benefit: dividing over- grown specimens can be good for them. The overgrowth becomes stunted or stressed and is more likely to be attacked by pests. These plants are also untidy and have fewer blooms.

In northern areas, a plant may need dividing every other year. In warmer climates with longer growing seasons, annual division may be necessary. (Some businesses offer this service to busy pond owners who don’t want the hassle. It provides added income and generates extra plants to sell later. It is also a popular topic for seminar schedules.)

Overgrown plants are usually stressed and therefore are more susceptible to nutrient deficiencies and pest attacks.
Overgrown plants are usually stressed and therefore are more susceptible to nutrient deficiencies and pest attacks.

Up to Your Elbows in Plants: Making the Job Easier

Some procedures will make propagating aquatics quicker and less stressful for both you and the plant. Most importantly, work in the shade whenever possible, especially when dividing or repotting waterlilies. Lily pads wilt and die very quickly when out of the water. Always keep any offshoots or cuttings moist until they can be planted.

The time of year that’s best for any type of plant propagation depends upon location, with spring being the most popular in both warm and cool climates. The new plants created then have a full season to develop. Because the air and water temperatures are more comfortable in late summer or fall, water gardeners sometimes divide overgrown plants then, after the aquatics have gotten to full size or outgrown their pots. This must be done with enough time for the plants to recover before winter arrives.

When a plant becomes overgrown it diverts energy to stay alive. All these baby lilies prevent the mother plant from blooming.
When a plant becomes overgrown it diverts energy to stay alive. All these baby lilies prevent the mother plant from blooming.

When dividing an overgrown potted plant, such as iris or papyrus, take it out of the pot and hose away all the soil. With the roots exposed, it becomes easier and safer to cut or pull apart the mass of roots. Trim away the older growth and keep only the newer sections for repot- ting. In cases of extreme overgrowth, it may be necessary to use a sharp shovel or a chainsaw to cut through stubborn clumps. When repotting the separated plants, place them in the pot based on their growth preference. For horizontally rooted plants (iris or hardy waterlilies) put the older section toward the container’s outside edge. For vertical-growing plants (tropical lilies, for instance) place the round tuber in the middle. Planting this way allows maximum room for new growth and extends the time before repotting will be necessary.

Aquatics grow in restrictive environments and need our help to thrive. Without it, they try to escape from confinement to search for food.
Aquatics grow in restrictive environments and need our help to thrive. Without it, they try to escape from confinement to search for food.

Extra plants should never, ever be discarded into the wild. For some invasive aquatic plants it might even be illegal. The potential for damage to local ecosystems is extremely high. If you can’t keep the excess for resale or to exchange with a colleague, add them to your compost pile. As a related note, you should always be up to date with aquatic plant varieties that are prohibited by federal and state regulations. (For a printable list, visit https://www.pondtrademag.com/ resources.)

Let Me Count the Ways: The Methods of Plant Reproduction

Unlike koi, plants have more than one way to produce offspring. In fact, it is common for aquatics to use multiple reproduction techniques. Certain tropical waterlilies are excellent examples. They produce seeds from the flower, offshoots from the tuber-like root and new little plants from the leaves.

We’ve already covered the popular and common division propagation method. However, there are times when other techniques may also be suitable for your business.

Irises are strong horizontal growers and able to jump pots when more space is needed. They can survive indefinitely without soil.
Irises are strong horizontal growers and able to jump pots when more space is needed. They can survive indefinitely without soil.
  • Division of rootstock: For convenience, this is the recommended method of aquatic plant propagation. Frequently used for marginals and water-lilies, the root masses are separated by pulling or cutting. This type of reproduction guarantees a second plant just like the parent, plus quick development of the offspring to maturity.
  • Seed: Although not all aquatics produce seeds, this method can be the easiest and cheapest way to obtain a large quantity of new plants. Unfortunately, seed propagation can take the longest to produce full-sized plants. Another factor is that like other sexual reproduction methods, the offspring may not look like the parents.
  • Offshoots from tubers and rhizomes: Waterlilies and some marginals can be propagated by cutting or breaking off the new eyes or side shoots from the parent rootstock. This occurs with both tubers of tropical lilies and rhizomes of hardy lilies or marginals. The little buds are then potted and will develop into a full-sized plant, usually within a growing season.
  • To make dividing roots easier, empty the overgrown plant (like this lotus) and wash away the soil.
    To make dividing roots easier, empty the overgrown plant (like this lotus) and wash away the soil.
  • Cuttings: Some fleshy aquatics can be propagated by stem cuttings, just like terrestrial plants. It is an easy way (neater than division) to get more plants exactly like the parents.
  • There are a limited number of plants that will grow from cuttings, including some submerged aquatics. (Many invasives spread this way.)

  • Runners: There are aquatic plants that send out runners with lots of new little plants, which send out runners with lots of new little plants, and … you get the idea. Water hyacinth is a well-known example that can overtake a body of water (small or large) if not killed by cold.
  • Seeds can be used to propagate some aquatics. It’s an inexpensive way to produce lots of plants, but much slower than division.
    Seeds can be used to propagate some aquatics. It’s an inexpensive way to produce lots of plants, but much slower than division.
  • Viviparous: This unusual method of plant parenthood is used by certain tropical waterlilies. New plants grow from the lily pads, piggyback-style. They can be potted and quickly develop into full-sized lilies. Although rare, a few hardy lilies produce new plantlets from the flowers. Some papyrus varieties are viviparous and produce offspring from the mop-like top of each stalk.
  • Plant new divisions according to how they grow. Horizontal aquatics should be placed at the pot’s edge to give them room to grow.
    Plant new divisions according to how they grow. Horizontal aquatics should be placed at the pot’s edge to give them room to grow.
  • Tissue culture: Also called cloning, this is done by a few specialized companies. Only a limited number of aquatics can be propagated this way. However, if significant quantities are required, tissue culture is a profitable way to produce completely uniform plants. The “Dwarf Giant” papyrus is a successful example. Research continues to find other aquatics suitable for this technique.
  • Multiply and Be Profitable

    Propagating plants is not rocket science. It is learning how to understand and utilize the plants’ natural growing cycles. In our field, this is especially important because aquatics grow in restrictive environments and need human assistance to adapt and to look good. Thus, mastery of basic propagation techniques can help you maximize both the aquatic plants’ appearance and your opportunities for profit from that knowledge.

    One overgrown tropical lily produced all these offshoots.
    One overgrown tropical lily produced all these offshoots.
     They can be potted to grow up looking exactly like the mother plant. Tropical waterlilies grow from round tubers, which develop small side tubers.
    They can be potted to grow up looking exactly like the mother plant. Tropical waterlilies grow from round tubers, which develop small side tubers.
    Those can be separated and potted. Hardy waterlilies grow from horizontal rhizomes. The small offshoots can be cut off and potted. They’ll mature rapidly.
    Those can be separated and potted. Hardy waterlilies grow from horizontal rhizomes. The small offshoots can be cut off and potted. They’ll mature rapidly.
    When plants have plenty of room and enough nutrients, they thrive and look wonderful.
    When plants have plenty of room and enough nutrients, they thrive and look wonderful.

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