Expert: Kenneth Joergensen - 7/1/2004

Question
I'm in zone 8.  My lillies are doing well and have been in same place for 3 yrs.  I would like to divide them and transplant.  When should I dig & divide?  how deep?  Use bone meal?  Thanks, M

Answer
I would wait until fall when the flower stem starts to turn brown and wither. Then dig up the bulbs and replant.

The bulbs should be planted in a hole which preferably has been amended with plenty of compost or humus (available in bags at garden centers and home improvement centers). Make sure you cover the lily with 2-3 times the amount of soil as the bulb is tall. Do not plant too shallowly. At the bottom of the planting hole, make a small mount of soil and then place the bulb on this mount. Spread the roots (which comes out from the basal plate at the bottom) around on either side of the mount. The tips should be pointing up Then backfill with about 1" of soil to cover the roots.
Next, I like to mix in a bit of annual plant fertilizer (such as osmocote 14-14-14) into the rest of the backfill soil. Or you can just fill the hole and then distribute the fertilizer on top of the soil after firming down. You can use any annual plant fertilizer of your choice.

Mulch the area with a 2-3" layer of shredded hardwood mulch or shredded leaves. Water very well for a long time to ensure the soil settles around the roots. I like to turn a gardenhose on and let it drip/trickle for about 1-2 hours to make sure the water really gets deep.

Smaller bulblets can also be replanted (use same guideline, e.g. 2-3 times the dept of the height of the bulb).

When you dig, dig deep as the bulbs do pull themselves deeper into the ground with age. Also several offsets may have appeared around the mother bulb and make the dig so wide that you do not accidently slice the bulbs. I like to dig a big "root ball" and then break it apart with my hands. You can also be guided by the flower stem.

Small pea sized bulblets should be planted really shallowly (1-2" soil to cover) and will flower in 2-3 years.

I am not into bone meal.

I am about to publish an article on monday about oriental lilies. The article will be published here:
http://www.suite101.com/article.cfm/18505/109330

The link wont work until monday July 5th, but I am providing it anyway because I think it may be of interest.

Kenneth