Normally a good time to do this would be in early Spring, once the pond thaws out and things are starting to warm up a bit - and before your lilies have started growing back too much.

Some people would recommend dividing your water lilies every year, but I don't think that's practical or necessary for most people (unless you're a pond nut like me), but after awhile you WILL have to divide your lily rhizome as it outgrows its current pot or planting container.

A good way to determine if your water lily needs dividing is if it's not blooming or producing nearly as many pads as normal. What can happen is the root (or rhizome) has become so overgrown that it has essentially run out of room in the pot, and can't effectively absorb nutrients to grow.

Fortunately, it's easy to remedy this problem - and you'll most likely wind up with several new lilies to plant, or give away to friends.

The first thing to do is to remove the pot, and dig up the rhizome from the pot. Notice how the root has become twisted and overgrown.

All you need to do in order to refresh and invigorate the plant is to either cut or break off and remove several sections of the root/rhizome to create a better root to soil ratio, letting the root more effectively absorb waterborne nutrients.

You'll be left with several new sections or baby lilies that you can then re-plant and grow into new plants of their own.

Now we'll take a look at how to fertilize your lilies (new and old) to make sure they're ready for Spring and Summer, and to make sure they'll keep blooming and growing all season long.

Here's a trick I use to fertilize my lilies quickly and easily...

Have a fairly wide tipped flathead screwdriver nearby, and then use it to punch a clear path into the soil and through the existing roots. Then give it a good twisting to hollow out your hole.

You'd be surprised how hard it can be to push a fertilizer tab down into a dense root pack - so try this next time and tell me if it isn't 100% easier.

Now that you have your 'holes' dug - take 3-4 water lily fertilizer tabs out (we like the Tetra Pond fertilizer tabs), and push them down into the holes with your index finger.

That's it -- you're done!

Once fertilized, you're ready to replant and put back in the pond.

It's a good idea to add some more 'fresh' soil (never potting soil), which I usually just dig up from the yard. Adding fresh soil will usually re-energize the plant, and give it some more room for its new roots to develop. I recommend a good 2"-3" of new dirt right on top.

Similarly, with your new Rhizome cuttings - plant them in a new container with some fresh soil on the bottom, and then covered by some more fresh dirt (around 1" for new cuttings). Use a shallow planter for the new cuttings, just to get them started. Once they start to grow again, move them to a deeper pot with more dirt.

Add some gravel on top, to keep you fish from burrowing in the dirt (as koi are known to do), but only a thin layer of pea gravel -- anything too deep will make it difficult for the new lily pads to 'push' through.

On existing lilies - I prefer to use the mesh bags for my lilies. They seem to allow a better absorption on nutrients from the pond water and I like the fact that I can cut holes in the corners and cable tie them over the dirt - to also keep the koi from 'burrowing' in the dirt. You can find these at most nurseries and water garden centers.

Here's another trick I use - Don't just drop the pot back into the pond, as trapped air bubbles can sometimes uproot the lily or some soil.

This is especially true for new pottings, as the soil has not been properly 'set'. Here's what I do:

Lower the pot into the water, just enough to fill it with water, then raise back up out of the water until you see all the air bubbles disappear.

Do this a few more times, until you think you've removed all the air bubbles from the pot. Then slowly lower it down into the pond.

There's nothing more frustrating than having a newly potted lily (or any plant) suddenly lift up out of the pot, dumping dirt all over the pond, and having to be repotted. It's happened to me more than once...

Brett Fogle is the owner of MacArthur Water Gardens and several other pond-related websites including www.MacArthurWatergardens.com and www.Pond-Filters-Online.com He also publishes a free monthly newsletter called PondStuff! with a reader circulation of over 9,000. To sign up for the free newsletter and receive our FREE 'New Pond Owners Guide' visit MacArthur Water Gardens today.