People often put water lilies in their backyard ponds because they are so pretty and well-known. They immediately make me think of peace and calm because of their big, floating leaves and beautiful flowers. But to keep your water lilies looking their best, they need to be divided every so often. Water lilies flower better when they are spread out so they don’t get too crowded. Follow this step-by-step guide to successfully divide your water lilies.
When to Divide Water Lilies
Water lilies should be divided every 2-3 years. Early spring is the best time, before the water gets warmer and new plants start to grow. When you divide in the spring, the new sections have time to get established before the heat of summer.
Signs that it’s time to divide include
- Decreased number of leaves and flowers
- Flowers smaller than previous years
- Lily pads appear crowded or are splitting pots
- Evidence of rot or dead foliage
Dividing relieves overcrowding and rejuvenates plants Don’t wait until plants decline to divide them.
How to Divide Water Lilies
Dividing water lilies is a straightforward process, but does require getting wet! Waders or old clothes and shoes are recommended.
Step 1: Remove the Plant from the Pond
Be careful not to hurt the leaves and growth that are already there as you lift the water lily pot out of the pond. Getting help from a friend is helpful because the pots are heavy.
Step 2: Wash Off Excess Soil
Spray off as much of the old potting soil as you can with a hose. This makes it easy to see the root and tuber mass.
Step 3: Locate and Remove the Tuber
The tuber is the thickened rhizome that grows horizontally under the soil and stores energy for the plant. Carefully remove the tuber from the pot and wash off any remaining soil.
Step 4: Trim Away Dead Roots and Foliage
Use a sharp knife or pruners to trim off any dead, damaged, or rotting roots. Also remove any dead foliage.
Step 5: Divide the Tuber
Examine the tuber for small bud-like growth points called eyes. These will sprout new growth. Cut the tuber into sections, ensuring each piece has at least 2-3 eyes. Pieces should be approximately 3-4 inches big.
Step 6: Repot the Divided Tubers
Place each tuber section in its own pot filled halfway with aquatic soil meant for pond plants. Position the tuber piece sideways with the eyes facing upward near the soil’s edge. Cover with more soil to secure.
Step 7: Return Plants to the Pond
Lower the repotted lily sections gently into the shallows of the pond. Allow them to acclimate before moving them into deeper water.
Caring for Divided Water Lilies
Once divided, water lilies require some specialized care to get re-established.
- Place in shallow water until new growth is visible.
- Provide supplemental fertilizer every 4-6 weeks. Use tablets formulated for aquatic plants.
- Remove any dead or damaged foliage to encourage new leaves.
- As plants mature, reposition into deeper water areas.
Dividing stimulates extensive new root growth. Be patient waiting for leaves and flowers as energy goes to root production first. With proper care, divided water lily sections will flourish, filling your pond with beautiful blooms.
Tips for Dividing Water Lilies
Follow these tips for optimal results when dividing water lilies:
- Use a sharp knife or pruners to make clean cuts when dividing tubers.
- Bigger is better – larger tuber sections re-establish quicker.
- Handle tubers gently to avoid damaging growth points.
- Disinfect tools with diluted bleach solution between plants to prevent disease spread.
- Repot into containers 2-3 inches larger than the root mass to allow for growth.
- Layer pea gravel on top of soil to prevent tubers from floating up.
- Start fertilizing when small leaves are visible at water’s surface.
Dividing Different Types of Water Lilies
While all water lily varieties are divided using the same basic process, there are a few differences depending on the type.
Tropical Water Lilies
- Prefer water temps above 70°F.
- Tubers are often clustered together and intertwined.
- Make sections containing a piece of the tuber’s growth tip.
Hardy Water Lilies
- Tolerate cooler water temps down to 50°F.
- Have larger individual tubers that are easily separated.
- Hardy lilies often spread via stolons in addition to tubers.
Lotus
- Not a true lily but requires similar dividing.
- Have tubers connected by rhizome “chains”.
- Carefully separate tuber sections from the rhizome.
- Keep at least one growth tip per section.
Common Problems When Dividing Lilies
Dividing water lilies is straightforward when done properly. However, here are some common issues to watch out for:
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Missing growth points – Without eyes, divided tuber sections will not grow into new plants. Always check for these before replanting.
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Wrong time of year – Dividing in mid-summer interrupts growth and flowering. Late fall dividing doesn’t allow plants to establish before winter dormancy.
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Inadequate fertilizer – Dividing is taxing on the plant. Supplemental fertilizer is vital for recovery and re-establishment.
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Water too deep – Newly divided lilies need shallow water until foliage is present. Placing replanted tubers into deep water is a common mistake.
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Inappropriate potting mix – Regular garden soil quickly turns to muck in water. Use porous aquatic potting media.
FAQs About Dividing Water Lilies
Here are answers to some frequently asked questions about dividing water lilies:
How often should water lilies be divided?
Plan to divide water lilies every 2-3 years for optimal plant health and flowering. Dividing annually is too frequent in most cases.
Can I divide water lilies in the summer?
It’s best to divide water lilies in early spring before new growth starts. Dividing in mid-summer will disrupt growth and flowering.
Do I need to fertilize divided water lilies?
Yes, applying aquatic plant fertilizer tabs every 4-6 weeks after dividing encourages faster recovery and growth of the new sections.
How long does it take divided water lilies to bloom again?
Depending on the variety and growing conditions, blooming typically resumes 12-16 weeks after dividing water lilies. Be patient, as the plant focuses energy on roots first.
Is it OK to divide water lilies into small pieces?
For fastest re-establishment, larger tuber sections with at least 2-3 eyes are best. Very small divisions may be slow to recover.
The Takeaway on Dividing Water Lilies
Dividing water lilies every few years is essential to maintain plant vigor and blooms in backyard ponds. Follow the steps outlined above taking care to avoid common mistakes, and you’ll have stunning water lilies again in no time. Pay close attention to using the right potting mix, fertilizing regularly, and initially keeping newly divided plants in shallow water. With proper care after dividing, water lilies will reward you with their spectacular summertime blooms.
Step two: divide the rhizomes
The one plant has been divided into three by making sure each piece has a growing point and roots.
Water lilies spread along rhizomes, which are chunky horizontal underground stems that new shoots and roots emerge from at intervals, as you find on irises. Along the rhizome the new growing points appear, which you can see in the above photos. Here I have carefully sliced the rhizome into three pieces, which is very easy to cut through using a sharp knife or secateurs.
I could have tried cutting into four plants but two of the growing points were very close and I only needed three. Chopping a plant up like this seems quite rough but it helps them. Some plants, such as water lilies, can slow down as they become congested in their pots. We can now give each of the three smaller plants its own large basket and nice, fresh compost.
Step three: add loam based compost
Pond plants must be grown in different compost to normal garden plants, it’s actually just soil rather than the multi purpose compost we’re used to. Luckily, aquatic compost shouldn’t contain peat, since peat will break down in the pond (read more on how to avoid peat). Instead, loam is used to grow plants in ponds. Loam is a fancy way of saying soil composed of a mix of sand, clay and silt. If you have a good loamy garden soil, you can just use your own. Otherwise, buy some aquatic compost. Be warned, it’s heavy!.
Hold the new water lily plants in the middle of the basket so that the growing point is level with the new soil, which should be about 0 5 – 1cm lower than the top of the basket. Carefully fill up the basket around the plant and firm in gently. This kind of water-based compost or loamy soil is heavy and dense, making it a good place for roots to grow.