When to Divide Lily of the NIle

Q. When is the best time of year to divide a Lily of the Nile? Please tell me how to do it. I have 1 that is about 10 years old and it isn’t looking very good.
A. The soil might be getting exhausted. They do like a fairly rich soil and if you do not apply compost to them frequently the soil can get mineralized and they will begin to look peaked (yellowing with little growth or poor flowering). They like organic mulches and do not like rock mulch at all.

Lily of the Nile has a bit different rhizome than some other plants. In the trades they refer to them as bulbs but they are not bulbs at all. It is late (April) to do it now but you can divide them in early spring (February) or fall around October 1 to 15.

You would wet the soil and lift them with a shovel being careful not to damage the “bulb”. After lifting them, wash the bulb (looks like fingers) with a strong stream of water from a hose and get the mud off of them. Cut them apart with a sharp knife. It is best to not divide them into too many small “bulbs” but you should have two or three growing points in each “bulb” that you replant.

Wash the cuts and dust them with a fungicide like Thiram or allow them to air dry in the shade before you replant them. Replant them with the buds (in the spring you may see a bud but in the fall it’s the end with the leaves) pointing up and about two inches deep. They can be planted about 18 to 24 inches apart with soil amended with compost and a starter fertilizer.