Dividing Hosta

Here are the two clumps I have chosen for division. The clump on the right is a sun beaten Hosta 'Colossal' 
and the one on the left is Hosta 'Francee'.

The 'Francee' is three years old and is at the perfect stage for division, while the 'Colossal' is six years old 
and the crown is too crowded.

As a rule the larger and more dense the clump the less divisions that are possible. On fast growing Hosta, 
three or four year plants produce the largest and best divisions, while on slower growing plants like
the 'tokudama' and 'Sieboldiana' types, old mature clumps that are eight or more years old produce
the easiest and largest divisions.
 

Our two clumps are ready for washing, note the hose end sprayer - this works well for cleaning the dirt 
off the crown and roots. Do not worry about damaging the roots with the jet of water- they are tough and can 
take the abuse.

Clean the dirt off of the top and then turn the clump onto its side and clean again; do this a number of times. 
It also helps to pull the roots up and off to the sides as you wash.

Personally, if I have the time, I take the clumps to the lake and swish them in the water while I am pulling each 
cluster of roots apart; the more dirt you get off the clump the easier it is to pull the divisions apart or to see where 
you need to make cuts.

The best tools I have found for the removal of Hosta clumps from the ground are the above fork with flat blades
and a tiling spade. Dig around the clump, starting six inches from the base of the clump.
Once you have cut a circle around the clump, pry the clump lose and pop it out of the ground.
On very large clumps in heavy rocky soils or clay based soils it can be a chore.
 

The dirt is washed off and I only lost one or two leaves. We want to keep as many leaves and as many roots
as possible on our new divisions so that the plant will grow fast and become strong for next year.

Hosta can be divided any time of the year, but mid to late summer is best, because at this time of the year plants 
are actively growing new roots. After some practice, you can produce nice plants that do not even look 
like they have been divided.

If you divide in the spring before the eyes have completely expanded, expect to have smaller and shorter leaves if
you have to use a knife and cut the crowns. If you can keep from cutting up the crowns you can expect 
good results with a nice balanced  clump shape.
 

If you divide in late spring after the leaves are out most of the way - many times you will end up with clumps that
look floppy the rest of the season or until new leaves grow if you choose to cut off the old leaves.
 

The less cutting that you can do on your clumps, the better your divisions will look and grow.

The first step, after cleaning the dirt off of the roots, is to pull any easily removable stems from the crown.

After you have removed the easy divisions, wash the clump again and pull the clump in half. Keep pulling the different
sections in half until you get to the number of stems per division you want. In most cases.
I divide my Hosta for increase or to sell the next year- so I divide down to single stems and keep them well watered 
and fertilized with a mild foliar spray.

To remove a stem from the crown, use a back and forth pulling motion and  not a side wise motion, work the stem
back and forth until it comes loose or breaks from the crown.  In the above picture, we see a nice large division on 
the right ready for potting up - it will have three or more eyes next spring. On those Hosta that are slower growing, 
like the large blues, a nice large well rooted single stemmed division like this one will give you a nice large mature 
single or double set of stems next year, with very large leaves.

The other two clumps I will divide more for multiplication purposes and half would be ready for selling and the other
half will go back in the ground to grow out.
 

A nice sharp knife will have to be used. Spread the roots out so that you can located a place to make your cut. 
Remember that you want to keep as many roots and leaves as possible, so make your cuts through the crown but 
not into the roots. I start by cutting the crown in half. I do this by placing the knife in the center of the crown, 
as far away as I can be from any large stems.

Make the cut about half way through the crown and then see if you can pull it apart by hand; use the same back 
and forth pulling motion. If you can't pull it apart then make the cut deeper.
 

If you are just making a division for a friend or another plant for a different place in the garden - these two pieces 
would make  nice looking clumps next year the way they are now.
 

From the 'Francee', I produced 20 divisions with ten large ones that were potted up for next year and ten that 
were planted back in the ground. All of them had a good set of balanced roots and will produce nice looking plants
next year that will be much large than our replanted divisions.

From the 'Colossal', I produced five divisions for selling and five that needed to be replanted. Those I had to replant 
will be smaller next year.

Once you have your divisions, the next step is planting them. Do not let the roots dry out too much. If you can not 
plant them right away, place some moist dirt or peat moss on the roots and put them in a place out of direct sun light. 
If your roots dry a little bit before you get a chance to replant - soak them in a bucket of water with a small amount 
of fertilizer. Do not leave the plants in water for more than a day, the roots will begin to rot.

For divisions that you have produced by pulling them apart and which have a nice balanced root distribution - 
plant your divisions about 1 inch deep- spread the roots out and cover the stems until you cannot see any of the 
white portions at the base of the stems. Water them in well so that there are no large air pockets in the soil.
Do not step on the soil around the plants - this will compact the soil.

If you had to use a knife and cut up the crown - plant the divisions around 1.5-2 inches deeper and water in well.